View Full Version : Grey card wrong?
Hello all.
I got out my Kodak grey card and decided to try something different. I had gone to the local craft shop and purchased a 150mm poly whatever (styrene I think) foam ball. You know, the white ones. I also purchased some cheap acrylic paint in tubes - one white, one black. I mixed up what I thought might be a good shade of grey and painted the ball with it. As it turns out it darkened a little upon drying.
Then I sat my newly painted but dry (not glossy) ball on a stick and had my daughter hold the Kodak grey card alongside in even but afternoon light ...
Guess what ? The centre of the ball came up with the same exposure as the incident reading yet the grey card - which does appear lighter and a little glossy I must say - gave a reading 2/3rds of a stop different. I was up pretty close to the ball and card so that the meter was reading in the centre of each.
I'm using a very new Sekonic L758DR mind you which talks in 1 tenth stops.
What do you think ? Could the grey card be out ? Should I now paint the grey card and the ball ?!?! Should I just get over it and leave the grey card alone from now on ? Lastly, should I use the grey card as-is but realise it is 2/3rds of a stop out of 'calibration' with my meter ?
Measurements were within 10 seconds of one another if you're thinking there may be a time factor in it.
This is not the first time I've queried the grey card mind you. It was out with my other meter too - an L358.
Rgds,
Steve
Disregarding the fact that the sun is upside down for you folks...
You're not using the gray card properly.
They're designed and calibrated for use with off-axis light, i.e. not coming from directly behind/above the camera.
The card should be oriented such that a line perpendicular to its surface bisects the angle between the light source and the camera.
The Kodak cards that I've purchased over the years included those instructions.
Perhaps they were missing from yours, or maybe Kodak no longer includes them (to save money).
Also, forgive the observation, but the quality control used to produce those cards exceeds the accuracy of your method by many orders of magnitude.
- Leigh
OK. Instructions are long gone I suspect. I don't recall seeing any actually.
The card is now probably towards 10 years of age ... does this make a difference ? The direction of the light wasn't completely behind me as such and adjustments on the angle of the card made diddly squat difference really. Not anywhere near 2/3rds of a stop. The difference is also backed up by another lightmeter.
I know this isn't the most scientific test but hey ! Cut some slack. The results are too far out to ignore and too far out to be because of an alignment problem. I just wonder if others have seen similar results or if there is a glaring problem with what I'm doing.
Its night time now but I could repeat at different incident angles to the card tomorrow but I don't think it'll make much of a difference.
The QC issue is between Kodak painted surface and Sekonic ? Hmmm. I guess I must trust the Sekonic as it will be the piece of equipment that comes with me.
Rgds,
Excuse me the sincerity but your experiment as well as its description borders on technical lunacy. A ball, measured in its centre - one must wonder about the weird idea. Sorry for the sincerity.
Hello all.
I mixed up what I thought might be a good shade of grey and painted the ball with it. As it turns out it darkened a little upon drying.
What do you think ? Could the grey card be out ? Should I now paint the grey card and the ball ?!?!
Steve
On second thought - most definitely. Take as many balls as possible and paint them up to the moment when it starts to be tiring. It could help.
Bruce Barlow
6-Apr-2014, 04:02
It is a well-known, totally unscientific fact that meters are often off, and 2/3 of a stop is not unusual. My 2 Pentax Digital meters are a stop apart at the moment, or would be if I had batteries... They were a stop off when they were both working. That's 2 meters aiming at the same thing from the same angle, with little room for error. I just changed the ISO on one so that the indicated exposures would match. From experience, I actually knew which one was correct.
If meters didn't go out of accuracy, Richard Ritter wouldn't make pocket change calibrating them. He routinely calibrates cinematographers' meters to have them match - I think one guy sends him 4 at once. 3 is not uncommon.
So just to make life more strange, I'll go with a meter that's off. If it's off so that you are overexposing by 2/3 of a stop, I'd even bet that they set it that way on purpose. Better shadow detail.
Wait a minute, just reread your original post. You said you took an INCIDENT reading? An incident reading reads the light source, not what the light is reflected from, using, typically, a little white hemisphere over the sensor. If that's so, you can't blame the grey card. Blame the sun, and now you have a real mystery. Cool!
I would also caution you that 2/3 of a stop is a lot less than you think, and your ball and the card may not be a match. Go into the darkroom and make 2 prints that are a stop apart. You'll be surprised, I think, at how similar they still seem to be. Then make 2 that are 2 stops apart. See what I mean? This exercise is fabulous eye training.
BTW, you said the ball paint darkened as it dried. Voila! You experienced dry-down in real life. Remember that when you make prints.
I am no expert but have read that an 18% gray card will only represent middle gray when the scene has a 5-stop range of contrast. An 18% gray card is perfect for copying flat documents for that reason because there's around 5 stops difference between black ink and white paper. The same card may be less than ideal as a "middle gray" reference for outdoor portraits, landscapes, etc.
You might find this article interesting: http://btzs.org/Articles/Sensitometry%20Part%205.pdf.
It is a well-known, totally unscientific fact that meters are often off, and 2/3 of a stop is not unusual. My 2 Pentax Digital meters are a stop apart at the moment, or would be if I had batteries... They were a stop off when they were both working. That's 2 meters aiming at the same thing from the same angle, with little room for error. I just changed the ISO on one so that the indicated exposures would match. From experience, I actually knew which one was correct.
If meters didn't go out of accuracy, Richard Ritter wouldn't make pocket change calibrating them. He routinely calibrates cinematographers' meters to have them match - I think one guy sends him 4 at once. 3 is not uncommon.
So just to make life more strange, I'll go with a meter that's off. If it's off so that you are overexposing by 2/3 of a stop, I'd even bet that they set it that way on purpose. Better shadow detail.
Wait a minute, just reread your original post. You said you took an INCIDENT reading? An incident reading reads the light source, not what the light is reflected from, using, typically, a little white hemisphere over the sensor. If that's so, you can't blame the grey card. Blame the sun, and now you have a real mystery. Cool!
I would also caution you that 2/3 of a stop is a lot less than you think, and your ball and the card may not be a match. Go into the darkroom and make 2 prints that are a stop apart. You'll be surprised, I think, at how similar they still seem to be. Then make 2 that are 2 stops apart. See what I mean? This exercise is fabulous eye training.
BTW, you said the ball paint darkened as it dried. Voila! You experienced dry-down in real life. Remember that when you make prints.
2/3 of a stop isn't much unless you're shooting chromes. Then it's a LOT and unnacceptable:)
ic-racer
6-Apr-2014, 06:46
http://dpanswers.com/content/tech_kfactor.php
Bill Burk
6-Apr-2014, 07:28
I'm using a very new Sekonic L758DR.
There is plenty of Internet information that explains 18% gray card is not the equivalent of incident mode. Meters are not calibrated to 18%.
I use the same meter and have the Sekonic gray card which includes patches in 1/3 stop intervals so I can find the patch that does give the same spotmeter reading as incident mode in the same light. I find the reading is closer to 12%, which agrees with correspondence I've had here and on APUG, and it agrees with Internet lore*.
Instead of confirming exposure with a gray card, I satisfy my "sanity" by taking a spotmeter reading of the palm of my hand. When I "place the reading on Zone VI," my readings agree well with the incident mode, and then I feel more reassured.
*But of course that doesn't prove the Internet lore is correct.
Bill Burk
6-Apr-2014, 07:34
http://dpanswers.com/content/tech_kfactor.php
This article looks like a better summary than usual...
Greg Miller
6-Apr-2014, 07:55
Hello all.
I got out my Kodak grey card and decided to try something different. I had gone to the local craft shop and purchased a 150mm poly whatever (styrene I think) foam ball. You know, the white ones. I also purchased some cheap acrylic paint in tubes - one white, one black. I mixed up what I thought might be a good shade of grey and painted the ball with it. As it turns out it darkened a little upon drying.
Then I sat my newly painted but dry (not glossy) ball on a stick and had my daughter hold the Kodak grey card alongside in even but afternoon light ...
Guess what ? The centre of the ball came up with the same exposure as the incident reading yet the grey card - which does appear lighter and a little glossy I must say - gave a reading 2/3rds of a stop different. I was up pretty close to the ball and card so that the meter was reading in the centre of each.
I'm using a very new Sekonic L758DR mind you which talks in 1 tenth stops.
What do you think ? Could the grey card be out ? Should I now paint the grey card and the ball ?!?! Should I just get over it and leave the grey card alone from now on ? Lastly, should I use the grey card as-is but realise it is 2/3rds of a stop out of 'calibration' with my meter ?
Measurements were within 10 seconds of one another if you're thinking there may be a time factor in it.
This is not the first time I've queried the grey card mind you. It was out with my other meter too - an L358.
Rgds,
Steve
Your test is flawed from the start. An 18% gray card is middle gray that reflects 18% of the light that illuminates it (18% reflectance). A styrene ball, being porous, will have a much lower reflectance value that 18%. So, using a reflective light meter, I owuld never expect to get the same exposure value when comparing an 18% gray card and a styrene ball (even assuming your styprene ball is really middle gray).
WayneStevenson
6-Apr-2014, 08:04
The Kodak Neutral Test Card tells you to hold the card in front of the subject so that it faces half way between the camera and the main light.
Importantly, it also states (this quote is actually taken from "Kodak Professional Black-and-White Films" but the card instructions say the same): "If you make a reflected-light reading from a gray card with incandescent illumination in the studio, use the exposure indicated by the meter. If you use the gray card to determine exposure outdoors in sunlight, increase the exposure indicated by the meter by 1/2 stop."
In dimly lit scenes, you can use the 90% white reflectance side, keeping in mind that there is a difference of five stops between your neutral gray and white (18% and 90% reflectance).
Bruce Barlow
6-Apr-2014, 08:23
2/3 of a stop isn't much unless you're shooting chromes. Then it's a LOT and unnacceptable:)
Agreed. What's color?
Kirk Gittings
6-Apr-2014, 08:47
There is plenty of Internet information that explains 18% gray card is not the equivalent of incident mode. Meters are not calibrated to 18%.
I use the same meter and have the Sekonic gray card which includes patches in 1/3 stop intervals so I can find the patch that does give the same spotmeter reading as incident mode in the same light. I find the reading is closer to 12%, which agrees with correspondence I've had here and on APUG, and it agrees with Internet lore*.
Instead of confirming exposure with a gray card, I satisfy my "sanity" by taking a spotmeter reading of the palm of my hand. When I "place the reading on Zone VI," my readings agree well with the incident mode, and then I feel more reassured.
*But of course that doesn't prove the Internet lore is correct.
However not everyones palm should be placed on ZI as pigmentation varies. Just saying as mine never reads one stop brighter than middle grey. But do I meter off it and place it on ZI in a pinch? You bet. Always gets me in the ballpark. In changing light with rapidly moving clouds etc. It gets me a quick relatively accurate exposure right off. Then for the next exposure I can take more time.
Bill Burk
6-Apr-2014, 10:03
However not everyones palm should be placed on ZVI as pigmentation varies. Just saying as mine never reads one stop brighter than middle grey.
Haaa, yes I keep forgetting people differ, and this is just what works for ME.
swmcl, if reading YOUR palm and placing on ZVI matches the reading from incident mode... Then, like me, you'll have a confidence-building quick check.
At least you will catch BIG mistakes like incident metering the light falling on your ear when you think you are spotmetering.
I went through the same doubt when my meter was new, and I was about to remove the K factor from the meter (because you CAN).
Until I found this much better plan... By USING the Zone System meter-and-place technique to confirm the Incident Mode.
I gave up the confidence-shaking result of working with a Gray Card and trying to remember the exact relationship.
...USING the Zone System meter-and-place technique to confirm the Incident Mode.
Sorry, Bill.
Incident metering is significantly more accurate in all cases than using the ZS.
Of course this assumes that you haven't mucked with the meter's calibration.
The ZS relies on your perception of tonality, which is imperfect even in a highly experienced practitioner.
The perceived reflectance (tonality or "zone") of a surface varies due to many factors.
Human perception of reflectance can be influenced by color, angle of incident light, angle of surface to line of sight, and reflectance of adjacent areas.
It's easy to demonstrate this fact by simply spotmetering a gray card at different angles.
That's why the instructions tell you to position it quite specifically relative to incident and lens axis.
- Leigh
Jim Noel
6-Apr-2014, 10:38
Gray cards fade with time and with exposure to UV.
Sounds like apples and oranges in technique. Either paint another flat card and then match the styles of reading, or recognize that you need to do an incident reading rather than a reflective reading from the ball because the shapes between flat and curved, no matter how small an area, change how the light reflects from the curve surface.
Bernard_L
6-Apr-2014, 11:58
The card should be oriented such that a line perpendicular to its surface bisects the angle between the light source and the camera.
Disagree. This maximizes the (unwanted) specular reflection. Use your gray card with sun incident at 45°, and meter staring along perpendicular. Please try and report back.
John Olsen
6-Apr-2014, 13:32
Right now I'm using my Calumet Grey Card as a base for shooting some silver jewelry. It works great for that. As for metering, I'd rather go with palm-of-hand as Zone VI or moderately-aged asphalt as Zone V.
One of the earlier commentors noted that his two Pentax Spotmeters were a stop apart. I've got two and they agree perfectly with each other. For the last 7 years they have held a particular spot on my darkroom wall as 7 2/3 EV. I check every time I pack them up. Please don't dis my meters!
Bruce Barlow
6-Apr-2014, 13:36
I have always found blue sky to be a reliable Zone V. I point my meter straight up on a cloudless day, or in-between clouds.
Thanks to all who contributed a helpful response to my ignorances especially Bill Burk. Confidence building is the key here. There are too many other things to worry about and now the 'K' factor too ! Off to read my palms !
I will trust the meters only and pretend the K factor doesnt exist. There is no way I'm getting meters calibrated. No way in the world.
To that, I will say that my photography took a giant leap forward a few years ago when I purchased my first flashmeter - the Sekonic L358. I generally go out of my way to get an incident reading - when I can - just to give me a 'reference' (my term) exposure - something in the ballpark. Reflected meter readings I do only when I absolutely have to - I find them OK only when I relate the reading to my incident 'reference'. I feel that insecure about reflected readings now !
Cheers
Kirk Gittings
6-Apr-2014, 15:07
Incident metering is significantly more accurate in all cases than using the ZS. Leigh
I've never used an incident meter but conceptually I've always had a doubt about using one in a common lighting situation I find myself in. When shooting landscape I often times find myself in lighting where my camera position is say in shade but the main subject in the distance is sunlit. What do you do with an incident meter in that situation?
My Pentax spot meter is good....but, only as good as the shutter accuracy of the lens I plan to use at the time and my development practices....not to mention my idea of where I should place a value. I like the Zone system with my palm at zone 6 as a starting point. If I remember to include filter factor and bellows draw........occasionally, I get it right.
I also use a Minolta auto meter IV F for my flash exposures....... that thing is amazing!!
Bruce Barlow
6-Apr-2014, 17:00
If you reel-y want to get good, each time you are going to use your meter, guess what the exposure will be first. Then meter, and figure out how to make your next guess better.
F'rinstance, I know that with my lens and shutter, Tri-X on a sunny day will be 1/60 at f22. Take it to the bank. On a day like that, between, oh, 10 and 3, all my exposures will be at that setting. On a cloudy day, I guess first, or if I'm in a special situation, I guess first. After a little practice, you'll see light much better, which is a useful thing.
Why wouldn't you want to have your meter calibrated? That said, "calibration" can amount to setting the ISO to where it gives you the "correct" exposure.
Bill Burk
6-Apr-2014, 18:20
Sorry, Bill.
Incident metering is significantly more accurate in all cases than using the ZS.
Of course this assumes that you haven't mucked with the meter's calibration.
The ZS relies on your perception of tonality, which is imperfect even in a highly experienced practitioner.
The perceived reflectance (tonality or "zone") of a surface varies due to many factors.
Human perception of reflectance can be influenced by color, angle of incident light, angle of surface to line of sight, and reflectance of adjacent areas.
It's easy to demonstrate this fact by simply spotmetering a gray card at different angles.
That's why the instructions tell you to position it quite specifically relative to incident and lens axis.
- Leigh
Incident metering has its strengths, among which are speed of work and accurate results. Nobody need ask more than that.
And I agree suppose you meter a random object, and plan it for a particular Zone, say Zone V... I would expect inaccuracies for all the reasons you stated.
But my "Zone System" readings usually agree with incident readings. Maybe it's because I have been practicing. I make multiple readings of the scene with the spotmeter (or reflective reading meter) and mentally "place" each reading in an intended Zone. Making multiple readings gives me the opportunity to favor some readings or throw out readings I think don't fit in. The reading I most often throw out is foliage. Palm of my hand is the most favored.
I get what Kirk Gittings says too, I was out not long ago with a meter (Sekonic TwinMate) that only has Incident and Averaging reflected light modes... But I was facing into the light and would have appreciated a spotmeter reading.
Bill Burk
6-Apr-2014, 18:23
If you reel-y want to get good, each time you are going to use your meter, guess what the exposure will be first. Then meter, and figure out how to make your next guess better.
F'rinstance, I know that with my lens and shutter, Tri-X on a sunny day will be 1/60 at f22. Take it to the bank. On a day like that, between, oh, 10 and 3, all my exposures will be at that setting. On a cloudy day, I guess first, or if I'm in a special situation, I guess first. After a little practice, you'll see light much better, which is a useful thing.
Why wouldn't you want to have your meter calibrated? That said, "calibration" can amount to setting the ISO to where it gives you the "correct" exposure.
Good advice to practice guessing in advance!
I think swmcl doesn't want to "calibrate" the meter in the sense that it's brand new and should have been calibrated correctly at the factory.
Bruce, I was thinking calibration would be changing some mapping in an IC inside the unit. No way. Simply dialling in a different ASA is entirely reasonable!
Kirk, in cases where I can't get to the subject because it is a landscape in the distance I try to get there even so !! Then again, the sunlight in Australia is pretty even and direct. Not too much atmospheric haze or some such (usually) so climbing the sandhill or some such is usually pretty close. My chrome failures would be 5% compared to previously relying on in-camera meters ('failure' for me is a grossy unacceptable image based on an exposure error)
Shutter accuracies aside !
Fair number of variables what !
Greg Miller
6-Apr-2014, 18:38
I've never used an incident meter but conceptually I've always had a doubt about using one in a common lighting situation I find myself in. When shooting landscape I often times find myself in lighting where my camera position is say in shade but the main subject in the distance is sunlit. What do you do with an incident meter in that situation?
An incident meter isn't going to give you scene dynamic range either in that situation. And our film records reflected light from actual reflective objects, not incident light.
There's millions of photographers successfully using both kinds of meters. Photographers just need to pick a metering type, and master it, just like all the other things we have to master in photography.
djdister
6-Apr-2014, 18:47
There's millions of photographers successfully using both kinds of meters. Photographers just need to pick a metering type, and master it, just like all the other things we have to master in photography.
So true. I would much rather hear about successful metering methods of either type rather than debating which type is better. I still remember the data sheets that Kodak packed in with film many years ago, and when guessing what my exposure should be (before metering) I still see that little diagram with Sunny, Cloudy Bright, Overcast, and Open Shade situations in my head. Sometimes I can recall the f/stop they recommended in those settings too...
ic-racer
6-Apr-2014, 19:34
Incident meter reading is only as good as the person taking the reading. How is it calibrated; to produce minimum acceptable density 3 stops or 4 stops from the indicated reading? Where to hold it? Sun? Shade? Aimed toward the light source? Aimed toward the camera? Half way in-between? Flat disk or dome? All those factors need to be accounted for to obtain the exposure.
Bruce Barlow
7-Apr-2014, 03:32
swmcl,
There's usually a little screw or two inside that adjusts the meter to calibrate it. It's pretty simple and quick, assuming you have a calibrated, known reference light source, which Richard Ritter has for just this purpose. So no remapping of anything inside happens.
That said, we agree that changing the ISO is faster, less expensive, doesn't require shipping your meter to Richard in the wilderness of Vermont. That'll keep you in the photography biz, now and forevermore.
Cheers!
Jim Jones
7-Apr-2014, 06:59
swmcl,
There's usually a little screw or two inside that adjusts the meter to calibrate it. It's pretty simple and quick, assuming you have a calibrated, known reference light source, which Richard Ritter has for just this purpose. So no remapping of anything inside happens.
That said, we agree that changing the ISO is faster, less expensive, doesn't require shipping your meter to Richard in the wilderness of Vermont. That'll keep you in the photography biz, now and forevermore.
Cheers!
The most obvious adjusting screw in many analog meters is a zero adjustment, not a calibration adjustment. With no light reaching the sensor, an analog meter should read zero when the meter is held in any position. If it is always off by a certain amount, the zero should be adjusted. Otherwise, low light measurements will be inaccurate. If the meter's zero reading is inconsistent when the meter is held in different positions, the armature is out of balance. The photographer might allow for this inconsistency, or have a qualified technician correct the problem. I agree with Bruce; it is better to understand meters and metering well enough to compensate for errors.
C. D. Keth
7-Apr-2014, 08:50
These are all good suggestions but none of them matter until the OP gets a new greycard. 10 years is really old for a greycard. It's probably faded or yellowed a quite large degree in that time.
OP, while I appreciate and encourage your curiosity, I don't see how your test is accurate at all. Surface specular reflection accounts for a great deal, as already mentioned. How did you determine the painted ball to be anywhere near middle grey?
These threads unfortunately and always rapidly degenerate into Zoney vs. Non. FWIW (apparently to none), in mostly normal contrast I pay little attention to middle grey (V) in the composition – I'm too busy reigning in (e.g., placing) shadows and highlights, sliding the scale as it were – V be damned. I do, however, focus on middle values more closely in low contrast situations or when I am having trouble deciding on whether highlights or shadows are most important in a very high contrast scene. I don't consider that to be an "imperfection", more of an asset.
Drew Wiley
7-Apr-2014, 09:25
Quality control tends to be horrible on gray cards. Plus they fade or get dirty. I told this story before, but I once measured a whole stack of them on a spectrophotometer, and not only were they vary greatly in reflectance, but also in color of gray, so that the spectral sensitivity point differed. I spotmeter scenes
based on a comparison of the various values and never use a gray card except for the studio copystand, where I understand what how particular gray will read.
The gray patches on unfaded MacBeath Color Checker charts are the most accurate I've found. I personally standardize on 18%, and since I did chromes for a long
time, don't allow even a third of a stop error in routine practice. I did make up a batch of true 18% paint once, which was accurate within plus or minus one percent over the entire visible spectrum. It took about two weeks to do using a high-end spectrophotometer and would be incredibly difficult for anyone else to replicate. Nobody casually mixing black and white paint together can do that. In fact, there is really no such thing as black. Every black pigment has a distinct spectral bias which is significant and has to be balanced out with something else. Some blacks like lampblack are purplish, and mineral blacks tend to be greenish.
The casual observer might not be able to see this, but once they're diluted with white, they're never ever neutral gray. Metamerism can be an understatement.
Disagree. This maximizes the (unwanted) specular reflection. Use your gray card with sun incident at 45°, and meter staring along perpendicular. Please try and report back.
Those are the instructions from Kodak for proper use of their gray card.
Argue with Kodak, not me.
- Leigh
...or moderately-aged asphalt as Zone V.
That's a precise reference if ever I heard one.
- Leigh
Incident metering has its strengths, among which are speed of work and accurate results. Nobody need ask more than that.
And I agree suppose you meter a random object, and plan it for a particular Zone, say Zone V... I would expect inaccuracies for all the reasons you stated.
But my "Zone System" readings usually agree with incident readings. Maybe it's because I have been practicing. I make multiple readings of the scene with the spotmeter (or reflective reading meter) and mentally "place" each reading in an intended Zone. Making multiple readings gives me the opportunity to favor some readings or throw out readings I think don't fit in. The reading I most often throw out is foliage. Palm of my hand is the most favored.
I get what Kirk Gittings says too, I was out not long ago with a meter (Sekonic TwinMate) that only has Incident and Averaging reflected light modes... But I was facing into the light and would have appreciated a spotmeter reading.
Hi Bill,
My comments were based on the use of "Zone System" metering without truly using the Zone System as a complete controlled process.
For the ZS to be used correctly requires an awful lot of calibration of every step from scene selection to the final print. I know of few people who have actually taken the time to do the required tests, and who then follow their process definitions religiously.
It can be easily demonstrated that any fully-defined process will yield consistent results if followed without deviation.
My comment about errors in ZS exposure are based on the fact that the human eye cannot perceive white as a defined value. The iris adjusts based on scene brightness, and the mind interprets the results by scaling the values.
True ZS practitioners can certainly achieve outstanding results.
I suggest that those who pick and choose aspects of ZS to be used while ignoring others are deluding themselves.
This is not to say that they can't achieve proper exposures. Anyone can do so if they do the same thing the same way every time. The point is that they're not using the ZS as defined by our friend Ansel, or any of its derivatives.
- Leigh
Drew Wiley
7-Apr-2014, 09:53
That's why roads were paved in the first place!
Drew Wiley
7-Apr-2014, 10:02
Leigh - the Zone System is actually crude. It's basically just a set of pigeonholes a stop apart, making it convenient to classify individuals shots for normal, plus,
or minus development. And different film & developer combinations can behave quite differently, so you'd hypothetically need a whole different ZS for every
significantly different set. Some people make a religion out of all this. No need. Black and white exposure isn't all that difficult unless you're doing something like
color separation negatives, in which can the Zone System is itself insufficient, and no substitute for plotting actual curves. So yes, I do pick and choose what applies to the shot, regarding ZS technique, and don't think I am deluded. More often, I'm visualizing in my mind, often intuitively and spontaneously from experience - but nonetheless visually the shape of the specific film curve, especially with regard to placement of readings on the SHAPE of the toe and highlight portions, so in this respect am a step ahead of what the ZS offers. But then I might label the shot plus or minus or whatever. If it works, it works. No need to
examine the entrails of an owl every shot.
More often, I'm visualizing in my mind, often intuitively and spontaneously from experience - but nonetheless visually the shape of the specific film curve, especially with regard to placement of readings on the SHAPE of the toe and highlight portions, so in this respect am a step ahead of what the ZS offers. But then I might label the shot plus or minus or whatever. If it works, it works. No need to
examine the entrails of an owl every shot.
That's hilarious Drew. Can I have your phone number for the next time I forget my spot meter? All kidding aside, I actually do appreciate what you mean though. Sometimes, I find myself slavishly and somewhat embarrassingly metering new scenes throughout the day where the light has not appreciably changed. I could have just taken the shot knowing either my previous aperture or speed. Doh! What fun is that?;)
Drew Wiley
7-Apr-2014, 11:22
I have had to do without a meter several times up in the snow, either due to frozen batteries or a dunked meter (= stupidity coefficient). Just from memory even my chromes came out perfect. ... wasn't guessing... just years of experience with similar lighting. The important thing in all this is sheer familiarity with one's chosen meter and the nature of the scene itself. I'd trust my own intuition more than the average gray card.
Kirk Gittings
7-Apr-2014, 11:44
I have had to do without a meter several times up in the snow, either due to frozen batteries or a dunked meter (= stupidity coefficient). Just from memory even my chromes came out perfect. ... wasn't guessing... just years of experience with similar lighting. The important thing in all this is sheer familiarity with one's chosen meter and the nature of the scene itself. I'd trust my own intuition more than the average gray card.
Jeez with all that experience do you even need film? :)
Drew Wiley
7-Apr-2014, 12:04
Obviously I needed film. I don't do Fauxtoshop. But that was spoken in the context of lighting conditions I've spent literally hundreds of photography backpacking
trips in. It wouldn't apply to just anywhere. And I was forced into it by meter, er, malfunction - in other words, my own stupidity dropping it in the creek. Now I
have a fully tight little clasp on the tripod which won't allow the meter loop to come free if I carry the tripod and camera rifle style. And some time back I learned to keep the meter in the sleeping bag during really cold nights. The only massive exposure bellyflops I've made recently were due to simply misreading the meter - so now habitually look at the little numbers on the spotmeter rings thru my focus loupe, so I don't have to pull out reading glasses. But even when I was a kid with just an external CDS meter clipped to an early Pentax, I never seemed to goof a shot on Kodachrome or that horrendously contrasty early Agfachrome. There were more important things to worry about, like not getting gored by a bull when taking a picture in a meadow...
Greg Miller
7-Apr-2014, 12:12
Jeez with all that experience do you even need film? :)
Aren't you glad you asked???
Kirk Gittings
8-Apr-2014, 19:34
Leigh, I asked you a question up at #24.
Alan Gales
8-Apr-2014, 20:27
Incident meters are all right but you just can't beat a Spot meter. With a spot I can read any part of the scene I want whether I'm in the same light or not.
Kirk Gittings
8-Apr-2014, 20:39
Incident meters are all right but you just can't beat a Spot meter. With a spot I can read any part of the scene I want whether I'm in the same light or not.
Exactly. That's what I don't get about incident.
When shooting landscape I often times find myself in lighting where my camera position is say in shade but the main subject in the distance is sunlit. What do you do with an incident meter in that situation?
Move into the same light as the subject, i.e. move out of the shade.
I did not claim that incident meters were universally more useful than spot meters.
No tool is most useful under all possible conditions.
I said they were more accurate, because they eliminate the subjective evaluation of tonality
inherent in the spot metering system.
A spot meter can be used to good advantage by a shooter who is experienced in its application.
But obtaining that level of proficiency can take a lifetime of practice.
- Leigh
Alan Gales
8-Apr-2014, 20:53
Exactly. That's what I don't get about incident.
The argument that I always hear is that it's fast.
Well, metering off a grey card or something that you feel is middle grey is just as fast to me. I don't know. I like my spot meter. It's definitely more versatile.
Your gray card is not wrong, your ball is wrong.
So you took four total readings. Incident v. reflected on the gray ball, and incident v. reflective off the card. On the theory that since you're taking the reading off the center of each, their reflective readings should match their incident reading. But you discovered that the incident and reflected reading from the flat gray card do not match each other, whilst the incident v reflective reading off the ball do.
This is actually quite interesting.
Since youre metering off the same card, it doesn't really make a difference if the card is faded or not etc.. And for the same reason,since you're using the same lightmeter for each reading, then lightmeter calibration is eliminated as a source of the discrepancy in the readings from the ball vs readings off the card. The same lightmeter should result in the same calibration discrepancy between reflective v incident readings off the ball compared to the card. So lets say that the incident meter is calibrated so that it is based on 13% gray instead of the card's 18% gray -- the same 5% difference should appear in incidence v reflective readings off of both the ball and the card. This would be true if the card was 22% gray or 2% gray since whatever the tone of the card, the difference in reflective v incident readings should be consistent. So again, neither meter calibration nor card calibration is the issue.
Other banal explanations exist though, such as how the card is tipped, and it could be that your lightmeter's sensitivity is plus-or-minus 2/3 of a stop (doubtfull. i hope) or, I would guess, it is a due to the reflectance off the texture of the material used.
Here's your answer, I bet. Really, the gray card is doing its job fine if the incident v reflective reading does not match for it. It isn't supposed to. So the real question is why do the incident and reflective readings match eachother on the ball. The ball surface is not as smooth as the card in reality, perhaps it is rougher and so does not reflect the light as well as the card surface... So the reflective reading does not show the discrepancy it is SUPPOSED to show assuming it was as smooth as the cards, but it just happens coincidentally that the reflective reading matches incident readings?.
Hmm... to test this theory you can use a second ball that is painted to match the color of the gray card exactly. >.. I think, thus eliminating the shape and texture differences in the material as potential confounding factors
Alan Gales
8-Apr-2014, 21:20
A spot meter can be used to good advantage by a shooter who is experienced in its application.
But obtaining that level of proficiency can take a lifetime of practice.
- Leigh
You know, Leigh, I agree with your first sentence but learning to properly use a spot meter can take a lifetime?
Leigh, I agree with your first sentence but learning to properly use a spot meter can take a lifetime?
Hi Alan,
I said "obtaining that level of proficiency".
That does not refer to pressing the button on the meter and reading the display.
Any kid can push a button and read a display.
I refer specifically to understanding and properly interpreting tonality of various subject elements.
- Leigh
Darin Boville
8-Apr-2014, 22:13
When I was a teenager i worked in a camera store. We had the Kodak card stock gray card. We had a smaller, plastic one from some other company. And one or two more. Maybe a Fred Picker book or something that claimed to have a gray card patch in it.
Of course, none of them metered the same. The didn't even look the same. And then you figure out that different meters give you different readings from the same card. Then that the reflected doesn't match incident.
Then, as a person just starting out in photography, you are completely befuddled.
--Darin
Alan Gales
8-Apr-2014, 22:38
Hi Alan,
I said "obtaining that level of proficiency".
That does not refer to pressing the button on the meter and reading the display.
Any kid can push a button and read a display.
I refer specifically to understanding and properly interpreting tonality of various subject elements.
- Leigh
You know, Leigh, I'm sorry but I just disagree. I never felt that learning how to use a spot meter was that hard. Of course in all fairness I must admit that I had quite a few years of shooting cameras before I bought my first spot meter.
Alan Gales
8-Apr-2014, 22:40
When I was a teenager i worked in a camera store. We had the Kodak card stock gray card. We had a smaller, plastic one from some other company. And one or two more. Maybe a Fred Picker book or something that claimed to have a gray card patch in it.
Of course, none of them metered the same. The didn't even look the same. And then you figure out that different meters give you different readings from the same card. Then that the reflected doesn't match incident.
Then, as a person just starting out in photography, you are completely befuddled.
--Darin
Don't feel lonesome, Darin. I think we were all befuddled back then.
I never felt that learning how to use a spot meter was that hard.
Alan...
Let me say this one more time.
Learning to use a spot meter is simple and easy. Any kid can do it.
Learning to accurately evaluate the reflectance of different textures, colors, and surfaces is a very complex challenge.
- Leigh
Alan Gales
8-Apr-2014, 22:53
Alan...
Let me say this one more time.
Learning to use a spot meter is simple and easy. Any kid can do it.
Learning to accurately evaluate the reflectance of different textures, colors, and surfaces is a very complex challenge.
- Leigh
OK Leigh. I got ya. Yes, you are right. It can be difficult. That's why you take multiple readings. I still don't think it's that hard but .....you do have a point. I still prefer a spot though. To each their own. :)
I still prefer a spot though. To each their own. :)
Hi Alan,
I use a spot meter quite frequently, probably close to 50% of the time.
The meters I carry are Sekonic L-558, which have incident, reflectance, and 1-degree spot all available.
My concern is that proper use of ZS metering is a complex subject, with many subtleties that can be lost on newbies.
I always recommend starting with incident reading to get familiar with the concept and environmental variables.
Once the student is able to get consistent results, then ZS can be introduced for finer control.
- Leigh
Alan Gales
8-Apr-2014, 23:36
Leigh, I started out as most of us with a reflective meter in a 35mm camera. I owned a Contax 139 with Zeiss lenses and shot Kodachrome 25 and printed with my Beseler enlarger with Schneider lens on Cibachrome. That's learning exposure the hard way. :) Everything so contrasty!
I fully understand using incident meters for students. It's easier for a newbie. For the experienced medium and large format crowd I feel a spot meter is the best way to go.
I used to hate in camera reflective meters but I have to admit that the in camera matrix meter in my Nikon D300 is unbelievable.
Steve Smith
8-Apr-2014, 23:59
It seems to me that a white card would be better than a grey card.
It would be much easier to get a consistent reflectance than with a printed grey colour and a greater percentage of light reflected makes for a more accurate reading, especially in lower light situations.
It just needs compensation added at the metering stage.
Steve.
Effectively then what I've done is paint a styro ball such that it gives me the same reading from the spotmeter as I get from using the incident meter (directed at the camera) at the same location in the same light. Being a ball and assuming the paint is uniform all over it should then give me a reading that is the same as the incident meter in all orientations. Not that there are that many given its got a hole in it for a stick !
I noticed that the reading from either ball or incident was around 2/3rds of a stop different to anything I got from the grey card. Yes the grey card is old and I reckon a bit shiny from sweating it out in a plastic sleeve for 10+ years too.
This query has evolved in directions not envisaged. It is precisely because I'm not confident enough in my own perceptive abilities when using spot that I rely on an incident reading to get me closer in the first place. Don't get me wrong, I do use spot and realise there are situations where one can only use spot but I much prefer to know the incident reading if possible. There certainly is a real skill in being able to use a spot meter effectively. There are a number on this forum who would be in the most elite of practitioners I'm sure.
Actually, what I have done in the past is take an incident reading and evaluate the scene. If there is a very wide range of values (landscapes in Aus can go well beyond a 11 stop SBR) then pull development. In fact, pull development anyway !
To a great extent I already know I'll lose information at either end of the spectrum so worrying about a stop here and there is a bit pointless I reckon. When shooting chromes bracketing is mandatory really. That or forget general scenes and perhaps focus onto a smaller lower SBR subject.
Quite a few years ago I got awarded a free licence for that SBR software with the Eiffel tower on its website ... Photomatix because I found a glitch that wouldn't allow certain large file sizes or they couldn't process them properly or something... I never did use the software again but I have been concerned with high SBR for some time just because of where I live.
One of the reasons for using Pyrocat-HD in glycol for me was that 'highlights don't blow out' ... but now I'm a bit bored with what I think is a bit of a flat tonality. I'm still learning though and hopefully always will to some extent.
Salute !
Effectively then what I've done is paint a styro ball such that it gives me the same reading from the spotmeter as I get from using the incident meter (directed at the camera) at the same location in the same light. Being a ball and assuming the paint is uniform all over it should then give me a reading that is the same as the incident meter in all orientations. Not that there are that many given its got a hole in it for a stick !
I noticed that the reading from either ball or incident was around 2/3rds of a stop different to anything I got from the grey card. Yes the grey card is old and I reckon a bit shiny from sweating it out in a plastic sleeve for 10+ years too.
This query has evolved in directions not envisaged.
Indeed, but I'm still trying to figure out your readings. How smoothly painted is the ball? would the surfce texture make a diffrernce i wondeer
djdister
9-Apr-2014, 08:16
Effectively then what I've done is paint a styro ball such that it gives me the same reading from the spotmeter as I get from using the incident meter (directed at the camera) at the same location in the same light. Being a ball and assuming the paint is uniform all over it should then give me a reading that is the same as the incident meter in all orientations. Not that there are that many given its got a hole in it for a stick !
I don't understand the use of a spherical shape for spot readings. Depending where you direct your spot meter, the ball will have shadows and highlights on it. The purpose of a ball shape on an incident meter is a different approach, such that it acts as a representative and averaging 3D collector of the illumination hitting an object, but I wouldn't select a ball shape to take a spot reading off of.
Kirk Gittings
9-Apr-2014, 08:40
Move into the same light as the subject, i.e. move out of the shade.
I did not claim that incident meters were universally more useful than spot meters.
No tool is most useful under all possible conditions.
I said they were more accurate, because they eliminate the subjective evaluation of tonality
inherent in the spot metering system.
A spot meter can be used to good advantage by a shooter who is experienced in its application.
But obtaining that level of proficiency can take a lifetime of practice.
- Leigh
Well that's the point isn't it. In a landscape the shade may extend for a mile or more. It's simply not feasible to always find a way to stand in the same light as the subject. This is a no brainer with a spot meter, but I don't know how I would asses an exposure here with an incident meter. I could get the shadows from where I am but I really need to know he brightness of the sunlit cliffs and the sunlit clouds to get at proper exposure and development-for me anyway. Also I would say it takes a couple of years of practice-not a lifetime.
Well that's the point isn't it. In a landscape the shade may extend for a mile or more. It's simply not feasible to always find a way to stand in the same light as the subject. This is a no brainer with a spot meter, but I don't know how I would asses an exposure here with an incident meter. I could get the shadows from where I am but I really need to know he brightness of the sunlit cliffs and the sunlit clouds to get at proper exposure and development-for me anyway. Also I would say it takes a couple of years of practice-not a lifetime.
Kirk,
That would be a very easy scene to meter with an incident meter. The value of the open shadow will be virtually same in the distance, where you are standing, or somewhere nearby. You can even simulate the shadow value by taking the reading in the shade of your vehicle, or under a tree. Yes, you need to know the brightness of the cliff, but not for exposure. You need to know this, and the brightness of other highlight values, for development. And this will be different for your process. One would develop differently for negatives that are to be scanned, for VC silver papers, and pt/pd. This of course you must determine with some system, perhaps Zone, or BTZS or some personal method. But it is a development issue, not an exposure one.
In any event, the landscape vista with cliffs and clouds would be a very easy subject for an incident reading for anyone with a working knowledge of BTZS, or failing that, just meter for the shadows and don't develop so much that you are not able to scan the highlights, or print them with your process.
Sandy
Drew Wiley
9-Apr-2014, 09:45
Gosh that's a magnificent scene, Kirk. Once again your timing was spot on. But with regard the other kind of "spot", namely spotmetering, it's good to keep in mind
that some of us use these things not only for black and white work but color also. Meters needs to be calibrated and understood not only in relation to gray value
but also spectral sensitivity, because the two things are actually related. The cell in the Pentax and Minolta spotmeters has peak sensitivity very similar to the
human eye, right around 550nm mid-green, then rather evenly tapers off each direction. The people who are generally way ahead of any of us in understanding
meter ability are obviously color filmmakers, and the Pentax was specifically manufactured for their needs. That's why there are IRE markings on these, and not just
EV values, or some paste-over Zone sticker like Fred Picker sold. I use such spotmeters for everything, even 35mm snapshot work, and find this method of working
much more precise than any TTL system. I'm not going to get in an argument over this versus the merits of incident metering, other than to state that the latter
method never really worked for me. Often I need to compare very small areas against one another.
Kirk,
That would be a very easy scene to meter with an incident meter. The value of the open shadow will be the virtually same in the distance, where you are standing, or somewhere nearby. You can even simulate the shadow value by taking the reading in the shade of your vehicle, or under a tree. Yes, you need to know the brightness of the cliff, but not for exposure. You need to know this, and the brightness of other highlight values, for development. And this will be different for your process. One would develop differently for negatives that are to be scanned, for VC silver papers, and pt/pd. This of course you must determine with some system, perhaps Zone, or BTZS or some personal method. But it is a development issue, not an exposure one.
In any event, the landscape vista with cliffs and clouds would be a very easy subject for an incident reading for anyone with a working knowledge of BTZS, or failing that, just meter for the shadows and don't develop so much that you are not able to scan the highlights, or print them with your process.
Sandy
What Sandy said. I for one am eternally grateful for his clear explanation of these principles.
Here's a sample photo where I just took one incident reading of my own shadow, shot the scene, and went home. (It took a while to get confident about this approach, but I rarely use my spot meter any more.)
Although I go way back with the Zone System, I didn't bother to check the clouds or the values of the rocks, sand, water etc. Besides, which rocks should be on which Zone anyhow ?
http://www.kenleegallery.com/images/forum/Ogun7.jpg
Andrew O'Neill
9-Apr-2014, 10:34
swcml, what was the purpose of your test? You have a gray card. Why not just stick with that?
Drew Wiley
9-Apr-2014, 10:46
In b&w work, my most critical metering involves how I want to separate the deepest shadow values, because that is something that cannot be retrieved later, esp
with the steep-toed films I generally prefer in landscape work. If the highlights are a bit off, that can be salvaged in film dev, using VC papers, masking etc. To
handle extreme contrast scenes I rarely opt for compensating or minus developing techniques because I want very full gradation in the midtones and highlights, as
well as the top and bottom end. I want my cake and eat it too. So I'll shoot something like TMY (or formerly things Bergger 200 or Super XX) which realistically allow one to work on a baseline clear down to Zone I or 0, and still maintain excellent gradation and micotonality. This kind of work would really seem to be a chore with an incident meter. I guess people just get used to whatever meter they own, and eventually get proficient in all kinds of lighting. But given the choice .... And I cut my teeth on color chrome work, which doesn't forgive very much so-called "latitude:.
Kirk Gittings
9-Apr-2014, 10:52
Thanks for the replies about my ignorance of how I would use an incident meter. The closest I ever came to owning one was my Weston Master V with the "Invercone" attachment which I owned back in the 60's and early seventies, but I never used it except as a reflected light meter. Since then it has all been Pentax Spot meters. Many photographers I respect have used incident so I know it works, just never saw any advantage over my spot and associated methods. Would anyone say there is an advantage over a spot meter or is it just an equal but different approach?
Drew Wiley
9-Apr-2014, 11:03
I could cite one distinct example around here where Sandy's incident advice could completely fail. Many summer afternoons the fog in the canyons breaks up
differentially, with a tongue still creeping up here and there. You could be standing in relatively soft light trying to meter something many stops more extreme in
redwoods in open sun, or visa versa. That kind of scenario happens to me rather frequently. The lighting can drastically change just in the time it takes to fetch
the filmholder and insert it. The "dance" with the light can be wonderful, but it's about like tarantulas mating sometimes - good way to kill an expensive sheet of film. I'm sure one of the Westons would have just scratched their heads and winged it based on sheer experience, and bagged the shot most of the time. Me too, sometimes. But a spotmeter takes a lot of the voodoo out of the equation. My late brother was an incident meter guy. Never did figure out how he got so good at it.
BrianShaw
9-Apr-2014, 11:23
.. Many photographers I respect have used incident so I know it works, just never saw any advantage over my spot and associated methods. Would anyone say there is an advantage over a spot meter or is it just an equal but different approach?
The advantage as I experience incident lgiht metering is that it can be quicker in lighting situations that are not too complex or critical.
In b&w work, my most critical metering involves how I want to separate the deepest shadow values, because that is something that cannot be retrieved later, esp
with the steep-toed films I generally prefer in landscape work. If the highlights are a bit off, that can be salvaged in film dev, using VC papers, masking etc. To
handle extreme contrast scenes I rarely opt for compensating or minus developing techniques because I want very full gradation in the midtones and highlights, as
well as the top and bottom end. I want my cake and eat it too. So I'll shoot something like TMY (or formerly things Bergger 200 or Super XX) which realistically allow one to work on a baseline clear down to Zone I or 0, and still maintain excellent gradation and micotonality. This kind of work would really seem to be a chore with an incident meter. I guess people just get used to whatever meter they own, and eventually get proficient in all kinds of lighting. But given the choice .... And I cut my teeth on color chrome work, which doesn't forgive very much so-called "latitude:.
For B&W films I can not imagine any scenario that would be easier for incident metering than the one you describe above. All that you have to do is decide in exactly what part of the scene you want to hold some texture and detail and take the incident metering at that spot. Hopefully that spot is not 50 feet down inside a cave.
As for your other scenario, no system is absolute and each depends on understanding what you are trying to achieve. My point is simply that exposure and development need to be addressed as two separate issues, regardless of what system you use.
Forget about chrome films if you are exposing for B&W negatives. Shooting chromes is actually a lot more like exposing with a digital camera.
Sandy
Kirk Gittings
9-Apr-2014, 12:04
The advantage as I experience incident lgiht metering is that it can be quicker in lighting situations that are not too complex or critical.
How so? In a pinch (where there is not too much contrast) I point the spot at a relatively well known subject value place that value on the respective zone and I have an exposure to use. Takes.......a couple of seconds. Where it takes more time is when I want to be critical and need to expand or contract contrast. Generally unless the subject is terribly flat I don't bother with expanded development but deal with it in PS or with variable contrast papers. I worry more about blown highlights on days with direct sun and deep shadows and sunlit clouds- and generally take more time then.
Drew Wiley
9-Apr-2014, 12:10
Well, sometimes it is literally fifty or a hundred feet down a cave or tunnel, looking either in to the depths, or out to overwhelming glare. I've got all kind of prints of such things. But how do I take a reading of some hypothetical texture in high-contrast intricate lighting, across a canyon with an incident meter, when where I happen to be standing is in a completely different kind of lighting? And why would I forget about chromes? I carry both color and black and white film, and truly attribute my precision with black and white to having had to learn exact metering beforehand. I don't want "some texture and detail" in the shadows - I want to know exactly where a reading is on the lower geometry of the film curve, and how the deep shadows will likely differentiate in the print. Unless I go thru the headache of shadow masking as a remedial resort, I don't reconfigure the curve like you might do in PS. Or lets say I'm up in the mtns under deep shade as the sun sets on my side of the canyon, but the entire opposite canyon wall is still under a fantastic variety of lighting. Am I supposed to do some Spider-Man leap
across something six thousand feet deep to take the reading, then instantly leap back to trip the shutter? ... Oh well... whatever works, I suppose. I'm happy
with spotmeters, obviously.
Darin Boville
9-Apr-2014, 12:12
We're not really having this discussion are we?
--Darin
Drew Wiley
9-Apr-2014, 12:16
Why not, Darin?
Drew Wiley
9-Apr-2014, 12:19
I should have qualified that. Doesn't use of a gray card inherently imply a reflected light reading?
I don't understand the use of a spherical shape for spot readings. Depending where you direct your spot meter, the ball will have shadows and highlights on it. The purpose of a ball shape on an incident meter is a different approach, such that it acts as a representative and averaging 3D collector of the illumination hitting an object, but I wouldn't select a ball shape to take a spot reading off of.
The idea behind using the ball to take a reflected meter reading (from the center of the ball) is to eliminate the shadows and highlights issue, so as long as the reading is taken from the center, the the orientation of the surface wont affect the reading -- it is automaticall evened out.
The purpose of my test is 5 styro balls in an arrangement such that I have 2 balls in the uppermost corner of the image, 2 black balls in the lower two corners and the 'middle grey' one in the centre. Its a 35mm image. The ball in the centre is quite large 150mm whilst the balls on the corners are quite small maybe 100mm but maybe 75mm. The balls do dominate the image. I think IIRC the grey ball fills the viewfinder well beyond the circle used for centre-weighted metering on my Nikon.
It all about running a roll of film for dev testing purposes. The balls in the corners let me know where to cut the film under all circumstances ! If the shot is grossly underexposed then the white balls will still show up on the neg and when the shot is grossly overexposed the black balls show up in the other two corners.
I stick the densitometer in the middle of the frame ...
The grey ball is a matt paint and is painted twice. There are no white bits and the surface is pretty evenly coloured (read - "I can't see any colour variation"). The grey ball is (hopefully) big enough for me to get a good or consistent average densitometer figure off for the test. It'll be OK !! I just need a gradient (contrast index).
But I should say that it is my thought for a number of years that an inflatable ball that did just this would be very handy. Grey cards are a pain because they need someone holding them and re-orienting them to the right angle - a real pain to use properly.
I'm a little outside the box and it probably doesn't obey a number of 'laws' but for my purposes right now it'll do !
The purpose of my test is 5 styro balls in an arrangement such that I have 2 balls in the uppermost corner of the image, 2 black balls in the lower two corners and the 'middle grey' one in the centre. Its a 35mm image. The ball in the centre is quite large 150mm whilst the balls on the corners are quite small maybe 100mm but maybe 75mm. The balls do dominate the image. I think IIRC the grey ball fills the viewfinder well beyond the circle used for centre-weighted metering on my Nikon.
It all about running a roll of film for dev testing purposes. The balls in the corners let me know where to cut the film under all circumstances ! If the shot is grossly underexposed then the white balls will still show up on the neg and when the shot is grossly overexposed the black balls show up in the other two corners.
I stick the densitometer in the middle of the frame ...
The grey ball is a matt paint and is painted twice. There are no white bits and the surface is pretty evenly coloured (read - "I can't see any colour variation"). The grey ball is (hopefully) big enough for me to get a good or consistent average densitometer figure off for the test. It'll be OK !! I just need a gradient (contrast index).
But I should say that it is my thought for a number of years that an inflatable ball that did just this would be very handy. Grey cards are a pain because they need someone holding them and re-orienting them to the right angle - a real pain to use properly.
I'm a little outside the box and it probably doesn't obey a number of 'laws' but for my purposes right now it'll do !
Nothing short of ingenious! If I can add my modest advice - continue to paint balls.
On second thought - would not 3 balls in the corners be better than 2?
Drew Wiley
9-Apr-2014, 13:45
OK. I've got the perfect idea. You can invest in my helium-filled bellows patent, but we'll paint the bellows middle gray, and without the "Goodyear" lettering on it like
an ordinary blimp.
Kirk,
The other reason for owning a incident flashmeter is the use of it in the studio or when using fill flash. One meter for every photographic situation. It is very fast to a generic photo of sorts. It is pretty difficult to not get a reasonable photo using an incident meter. A perfect exposure would vary from the incident reading by experienced people using a reflective meter in my opinion but sometimes even a one degree spot is too big and I note the progression of the small format digital cameras towards sensing gazillions of spots in the image trying ever so hard to do the job for you ...
:-)
Greg Miller
9-Apr-2014, 14:15
Kirk,
The other reason for owning a incident flashmeter is the use of it in the studio or when using fill flash. One meter for every photographic situation. It is very fast to a generic photo of sorts. It is pretty difficult to not get a reasonable photo using an incident meter. A perfect exposure would vary from the incident reading by experienced people using a reflective meter in my opinion but sometimes even a one degree spot is too big and I note the progression of the small format digital cameras towards sensing gazillions of spots in the image trying ever so hard to do the job for you ...
:-)
As I wrote earlier in this thread, there are millions of photographers successfully using both types of meters. So to each their own, and whatever for for each is all good.
As for me personally, I have used a hand held spot meter (which had a built in incident meter as well) for LF chromes, and built-in reflective meters in 35mm cameras for chromes. And never had a problem with getting exposure correct (usually bracketing 2 shots at 1/3 stop difference between the two). I did a 2 week paid expedition (hired to be the expedition photographer) in extremely remote Patagonia where I could carry only enough chrome film where bracketing was not an option - and only lost 2 photos in extremely difficult light for the entire trip due to bad exposure. I just can't image doing that with chrome film with an incident meter (while recognizing that those who have mastered an incident meter might feel otherwise). Even today with a Nikon D800 with a dynamic range capability much more forgiving than chrome film, I would prefer the built in reflective meter for exposing to the right than an incident meter. I'm sure others who primarily use an incident meter might feel differently, but I have always used a reflective meter, it didn't take a lifetime to figure out, and consistently get accurate exposures. And I am doing paid assignment where I have one chance to get the photos and bad exposure is not an option.
Indecent and repulsive - sorry, I meant - incident and reflective, couldn't we all get along?
In b&w work, my most critical metering involves how I want to separate the deepest shadow values, because that is something that cannot be retrieved later, esp with the steep-toed films I generally prefer in landscape work. If the highlights are a bit off, that can be salvaged in film dev, using VC papers, masking etc.
Yep.
Something about "Expose for the shadows, develop for the highlights." (I didn't invent that rule.)
- Leigh
Drew Wiley
9-Apr-2014, 15:16
Yes and no. Ya obviously gotta expose for the shadows, or there'd be nuthin there to work with. But how I prefer to handle the highlights often differs from the
conventional Zone System approach. Nowhere have I seen proof that God created the world in Eight Zones. That is an arbitrary convenience for "average" film
conditions. Some films will handle twelve "zones" of relatively straight line without resorting to minus or compensating development. How you choose to print that kind of potential goes a bit beyond this thread, however... But catching up on this chatter, I don't see what the point of metering is if you have to bracket to get what you want. That should be real fun to the wallet when shooting 8x10; and let's hope nothing changes between shots, if it's outdoors, which will happen. ... Then that mix half black and half white paint together to get middle gray thing? Well, if it works, it works. But it won't be middle gray by any conventional photographic standard of conversation, because black pigment is more more aggressive than white. It's like mixing 50% eggplant and 50% cayenne pepper - you won't get 50% "warm"!
But I should say that it is my thought for a number of years that an inflatable ball that did just this would be very handy. Grey cards are a pain because they need someone holding them and re-orienting them to the right angle - a real pain to use properly.
Technically, this is brilliant...but I'd feel silly blowing up a ball or ballon whilst people stare at me and my 8x10 anyway.
I honestly cant figure out your metering inconsistency. Other members seem to have written the issue off and are instead discussing incident v reflective metering in general...
The purpose of my test is 5 styro balls in an arrangement such that I have 2 WHITE balls in the uppermost corner of the image, 2 black balls in the lower two corners and the 'middle grey' one in the centre.
I fixed that for you -- now it makes more sense.
Drew Wiley
9-Apr-2014, 16:15
Some commercial "gray cards" are actually made of relatively shiny plastic.... and would obviously be hell to read.
Then that mix half black and half white paint together to get middle gray thing? Well, if it works, it works. But it won't be middle gray by any conventional photographic standard of conversation, because black pigment is more more aggressive than white. It's like mixing 50% eggplant and 50% cayenne pepper - you won't get 50% "warm"!
He's not trying to get middle gray -- any gray works. Something middle-ish is good enough.
Similarly when you're running a film speed test and are advised to photograph a towel for the Zone System the color of the towel doesn't matter.
Drew Wiley
9-Apr-2014, 16:30
Just depends. If you're trying to target a particular end-point density, the color can matter a lot, because different meters are color-biased in what they see, just
as panchromatic film are themselves. And it depends on whether you're trying to do hard sensitometry or just a casual evaluation of the elbow room of your film and
lighting setup. So yeah, I understand what he's doing, and his system seems to work. But tying that into what a gray card is "supposed" to do is another matter.
Sometimes when I've needed a huge "gray card" to check eveness of illumination under a set of copy lights, I simply used a big gray sheet of matboard. But I also
knew either how to skew the result to a more official reading, or had a more trustworthy small gray scale nearby to place at various points on the surface. Jerryrigging is half the fun of studio setups.
Cyrus !
Well spotted. Yes, two white balls in either the top two or bottom two corners and black ones in the other two corners.
Sorry for the confusion.
Bill Burk
10-Apr-2014, 18:29
swmcl,
You could add a "steelie" or two, Ralph Lambrecht includes one on his "Zone Cube" and it's cool to have the shiny metal sphere in your tests.
I personally would prefer the center spot to be a flat disc instead of sphere. But for a test image, you sound like you are having fun.
Bill Burk
13-Apr-2014, 21:23
Instead of confirming exposure with a gray card, I satisfy my "sanity" by taking a spotmeter reading of the palm of my hand. When I "place the reading on Zone VI," my readings agree well with the incident mode, and then I feel more reassured.
I'll have to re-think this. I'm beginning to think that there is a 2/3 stop shift between Zone System calibration and standard meter calibration. Maybe my palm at Zone VI agrees with incident. But if I place shadows on Zone II... I don't think I can expect agreement.
I think I should NOT expect different metering techniques to agree. I should expect a 2/3 stop difference. When metering Zone System style, I would need to use Exposure Index 250 and I should expect that to agree with Incident reading when used with Exposure Index 400.
In practice this is kind of what I have been doing: I set my meter at 250 where I use it for everything until I "need" the 400 speed for some reason, like if I want to do indoor candid photography and I want to shoot handheld. Then I'll set the meter for 400 and use it in a more standard way.
I'll have to re-think this. I'm beginning to think that there is a 2/3 stop shift between Zone System calibration and standard meter calibration. .
If so then this should be apparent and also consistent regardless of the meter or metering technique
Drew Wiley
14-Apr-2014, 08:14
With black and white technique, you basically set your own standards of what is workable. There is nothing absolute about Zone system placements. You tailor them
to your own needs. Color photography, esp with chromes, tends to be more specific, but even then its's more important to be spontaneously comfortable with your
chosen meter technique than to make a religion out of this.
What Sandy said. I for one am eternally grateful for his clear explanation of these principles.
Here's a sample photo where I just took one incident reading of my own shadow, shot the scene, and went home. (It took a while to get confident about this approach, but I rarely use my spot meter any more.)
Although I go way back with the Zone System, I didn't bother to check the clouds or the values of the rocks, sand, water etc. Besides, which rocks should be on which Zone anyhow ?
http://www.kenleegallery.com/images/forum/Ogun7.jpg
With all due respect, and appreciating the fact that you've posted a fine example image, I don't see a lot of shadow detail in large parts of the image. Maybe that is what you intended, but your last statement about not bothering to check important values when you were using it seems to indicate that you weren't fully utilizing the ZS as designed for fine art B/W expression. "which rocks..." indeed – that's the point of using a spot meter with the ZS. Often it is unnecessary to use targeted metering, particularly in wide landscape compositions where incident metering is sufficient, but it can really save your bacon and keep your visualization on task in difficult lighting.
Drew Wiley
14-Apr-2014, 11:18
Nuances aren't something conveyed very well on the web, so I'll withhold my opinion of what might or might not be on that negative.
With black and white technique, you basically set your own standards of what is workable.
There is nothing absolute about Zone system placements. You tailor them to your own needs.
Exactly.
- Leigh
djdister
14-Apr-2014, 12:41
With all due respect, and appreciating the fact that you've posted a fine example image, I don't see a lot of shadow detail in large parts of the image. Maybe that is what you intended, but your last statement about not bothering to check important values when you were using it seems to indicate that you weren't fully utilizing the ZS as designed for fine art B/W expression. "which rocks..." indeed – that's the point of using a spot meter with the ZS. Often it is unnecessary to use targeted metering, particularly in wide landscape compositions where incident metering is sufficient, but it can really save your bacon and keep your visualization on task in difficult lighting.
I don't know, I can see at least four zones in just the rock areas, and if I saw a print I could probably make out 5 different zones in the rocks alone. It is quite possible that in the time spent and analyzing spotmetering zones 1, 2 and 3 in the rock areas, the light would be gone...
Drew Wiley
14-Apr-2014, 12:43
Spotmetering shadow situations like that takes about three seconds.
djdister
14-Apr-2014, 12:44
Spotmetering shadow situations like that takes about three seconds.
And how would the end result have turned out better?
Drew Wiley
14-Apr-2014, 12:51
Because I know, almost instantly, exactly where a specific spot of shadow will fall on the scale in relation to the other key values. The little EV scale on the top of
a Pentax spotmeter is very very convenient for such assessments. There's a reason it's such a popular tool around here.
Greg Miller
14-Apr-2014, 16:30
Exactly.
- Leigh
Which is precisely where the artistive/creative side of photography begins. Perfect technique only gets you to a technically perfect image. Which could be deadly boring, like a player piano. Or could be incredibly moving as a technically perfect image with a unique creative vision. Knowing where the individual tones read on the meter, then choosing how they will render on film, and subsequently in a print, is very powerful for those with a creativite vision. Of course if one has no artistic vision, then they can settle for a technically perfect print that says nothings and moves no-one to feel anything.
Mastering technique is very important, but not an end to itself. Mastering technique so that it becomes instinctive, frees the creative right side of the brain to dominate and that's when the real photography begins.
Bill Burk
14-Apr-2014, 23:38
Ken Lee and Kirk Gittings, your two examples are beautiful and I find it interesting that they almost "tell" of the metering that you did.
Perhaps it's because you selected them to illustrate the statement you were making, but they both fit their descriptions well.
Ken yours evokes the mood of Garrapata Beach by Brett Weston with its stark shadows and bright wet highlights. Kirk, yours evokes the mood of your lightning shot (I don't know exactly how but I suppose that means it's recognizably yours). I don't know how an incident meter would work in that situation. Neither foreground nor cliffs are illuminated same as you.
I prefer to practice all the kinds of metering because I enjoy the journey, and I'll use whatever I have on hand. I am sure I can make anything work, and I am always grateful for the tolerance. But Kirk, yours is the kind of problem that probably is best met with a spotmeter.
Bill Burk
17-Apr-2014, 14:42
Continuing to explain my change in position on this thread - as reflected by reality - When I meter in incident mode, and then switch to reflected-light mode to use a Zone System evaluation (like placing a reading of the palm of my hand on Zone VI)... DOES NOT result in the same reading either way.
What I get by reading two different ways, are two different exposure recommendations, both of which may be considered valid.
Then I make a decision which one fits my needs of the moment. If I need speed for handheld in low-light situation, I might choose the lesser exposure. Otherwise, I usually take the reading that suggests more exposure.
Ken Lee
17-Apr-2014, 15:22
http://www.kenleegallery.com/images/forum/2014-04-02d.jpg
Initially skeptical, I eventually found - and continue to find - that a single incident reading for the shadows always agrees with the reading I derive by taking multiple spot-meter readings.
Last weekend I made this photo and because of this thread I had some doubts - so I checked everything with my 1-degree spot meter. The indicated exposure was the same.
I'm sure there will be situations where one method or another is inadequate. However, for 99% of the use-cases I encounter, the incident reading is reliable. It's not perfect, it's not exclusive, it's just... very convenient.
We might even say that the necessity of a spot meter is one of those "Beliefs" inherited from our "forefathers" (http://www.largeformatphotography.info/forum/showthread.php?112769-quot-Beliefs-quot-inherited-from-our-quot-forefathers-quot).
Bill Burk
17-Apr-2014, 15:42
Initially skeptical, I eventually found - and continue to find - that a single incident reading for the shadows always agrees with the reading I derive by taking multiple spot-meter readings.
When you take the meter reading for the shadows, do you adjust exposure downward in order to make the shadows realistically "darker" than meter suggests?
Reading BTZS I find this is recommended, and since I found I should expect a 2/3 stop difference between incident and reflected... I'm looking for possible reasons why your readings agree with each other.
And if you take your shadow incident reading literally - don't change what you do if it already works for you. It may be that you cancel out the differences between metering incident and spotmetering by NOT compensating when you read incident light in the shadows.
Drew Wiley
17-Apr-2014, 15:52
Brett's approach was really very different (not to slight Ken's image - I'm referring to the visual strategy). He wanted his graphic shadows blacked out, and seems to have often deliberately underexposed and overdeveloped the neg to get both that effect and very rich midtone gradation. And apparently, he didn't generally use meters at all, but worked from memory. Merg Ross could no doubt describe this more accurately than me. But sometimes I use the same strategy myself - not often;
but once in awhile I quite deliberately aim for that BW look in a print, and in my case, I do it with a spotmeter, so I can deliberately lop off a zone or two from a
steep-toed film, then plus-develop.
Ken Lee
17-Apr-2014, 15:55
As suggested in the BTZS book, I set the ISO to 1 stop higher than the ISO at which I rate the film. Since I rate TMY and HP5+ at 200, my incident meter is set to 400.
Beyond the Zone System, 4th Edition, "Metering for the Incident System" pp 134:
"Notice that these film speeds seem exaggerated; they are, in fact, just double the normal speeds. As explained earlier, this is done deliberately to compensate for the 1-stop overexposure that normally results when the camera settings are based on the low-light incident reading."
Bill Burk
17-Apr-2014, 16:00
Great Ken!
Is your spotmeter set at 200 then? It would make sense if you do.
The OP uses an all-in-one meter, the L-758DR which has an ISO1 and ISO2 setting that might be used to follow the BTZS shadow metering technique.
Drew Wiley
17-Apr-2014, 16:11
I'd sure like to see how some of you incident junkies would manage the intricately dappled light here in the redwoods when the sun is out, and twelve stops of range
come into play. It can change by the minute. Guess one just gets accustomed to whatever.
Bill Burk
17-Apr-2014, 16:23
That's when you use the two-exposure trick... One very brief exposure to catch the highlights only... then wait 5 minutes for the fog to roll in and make the base exposure.
sanking
17-Apr-2014, 18:18
I'd sure like to see how some of you incident junkies would manage the intricately dappled light here in the redwoods when the sun is out, and twelve stops of range
come into play. It can change by the minute. Guess one just gets accustomed to whatever.
Assuming we are talking about exposing B&W film this is more of a development issue than an exposure issue. And the fact that the sun is coming and going is not relevant because the reading in the deepest shadow (area not touched by the sun) is not going to change much regardless of whether the sun is shining or hidden by clouds. So whether the sun is shining, or covered by clouds, you could take an incident reading in an area of very deep shadows similar to the spot in the deep redwoods, or you can take a spot reading of the shadows and then figure out how to place it.
But ultimately it is more of an aesthetic issue than one of metering. Do you want to develop the film to show the entire range of tonal values from deepest shadows to highlight highlights, or do you intend to sacrifice one or the other? For this knowing the subject luminance range and how to develop the film for that range is the critical issue, not how you measure the SLR.
Either way, it would not be difficult to meter a scene like that with an incident reading. I could do it with a spot meter also as my meter is a Sekonic that offers both incident reading, and 1º spot.
Sandy
I'd sure like to see how some of you incident junkies would manage the intricately dappled light here in the redwoods when the sun is out, and twelve stops of range come into play.
You're not going to capture twelve stops of range on normal b&w film regardless of how you expose it.
Black is black, as the song says.
- Leigh
Bill Burk
17-Apr-2014, 20:15
You're not going to capture twelve stops of range on normal b&w film regardless of how you expose it.
Black is black, as the song says.
- Leigh
That's where you can use the Fred Picker trick, double exposure, to solve the problem of sun filtering through trees. He explained how he did that on Millerton, New York, 1970
When a cloud covered the sun, he shot the scene with leafy areas on Zone IV. Then he exlained... "When the sun dapples reappeared, I made a meter reading of a nearby sunlit leaf and placed that value on Zone VII."
I could have used those sun dapples today, as it was generally foggy when I was out shooting. Sun did come out later, but that trick wouldn't have been practical. For Fred Picker's trick, you need partly cloudy.
Drew Wiley
21-Apr-2014, 14:11
Double exposure doesn't sound like a very good formula if you don't want a lot of blurred foliage or unpredicatable shadows. And otherwise, yes some films will handle twelve zones. You need a very long straight line film, and then maybe a few tricks in your bag. But compensating of minus development doesn't have to be one of them. There are ways to have your cake and eat it too.
Bruce Barlow
21-Apr-2014, 14:21
I'd sure like to see how some of you incident junkies would manage the intricately dappled light here in the redwoods when the sun is out, and twelve stops of range
come into play. It can change by the minute. Guess one just gets accustomed to whatever.
I pick up the tripod and walk away, and I'm a reflected spotmeter guy. Never seen one worth making anyway. God invented the sun to frustrate photographers, just like all utility engineers are frustrated photographers, so they route poles and lines through all the best potential compositions.
Drew Wiley
21-Apr-2014, 14:37
I'm fascinated by the complexity of forest lighting. Sure, sixty percent of the time, by the time I've got the camera set up of in focus, the light has shifted, and I just
pack things back up. Then the other forty percent of the time, I'll gamble the shot. Maybe a third of those will be what I anticipated. The shadow patterns move around remarkably quickly. Calculating exposure per se if the easy part. Life is a lot easier when the fog is in; but those are different kinds of opportunities.
I must reply back since I started it ...
I went ahead with my tests and they worked to some extent. I have not seen a 35mm roll of film for so long my idea of putting a ball in each corner really wasn't that necessary as I had imagined. The edges of each frame were fairly clear as it turns out. But the idea itself wasn't a failure. I got a film curve or two for my troubles.
The other day was a very miserable overcast day. I plopped the Kodak grey card against an outside wall and took an incident meter reading along with a spot reading from the card... They were identical. Furthermore, I tilted the card this way and that and they remained identical!
So.. I bought out the ball.
It measured the same too.
The next day was back to a normal sort of clear and direct light that is usual. The ball readings worked when the light source was basically over my shoulder. When the light source was more across the ball there was some more variation.
Lesson learned.
The quality of the light makes a difference and so too the directionality. I think the grey card is shinier than when I bought it because it has been stored in a sealed heavy plastic envelope for many years. It never was more than 2/3rds of a stop different to the incident meter anyway.
Cheers!
I must reply back since I started it ...
I went ahead with my tests and they worked to some extent. I have not seen a 35mm roll of film for so long my idea of putting a ball in each corner really wasn't that necessary as I had imagined. The edges of each frame were fairly clear as it turns out. But the idea itself wasn't a failure. I got a film curve or two for my troubles.
The other day was a very miserable overcast day. I plopped the Kodak grey card against an outside wall and took an incident meter reading along with a spot reading from the card... They were identical. Furthermore, I tilted the card this way and that and they remained identical!
So.. I bought out the ball.
It measured the same too.
The next day was back to a normal sort of clear and direct light that is usual. The ball readings worked when the light source was basically over my shoulder. When the light source was more across the ball there was some more variation.
Lesson learned.
The quality of the light makes a difference and so too the directionality. I think the grey card is shinier than when I bought it because it has been stored in a sealed heavy plastic envelope for many years. It never was more than 2/3rds of a stop different to the incident meter anyway.
Cheers!
In case of doubt why not use both flat gray cards and the famous painted balls in corners and the centre together in different lightning situations and learn a lot of lessons from it? Why give up just because of an overcast day?
Bill Burk
1-May-2014, 23:17
good to hear swmcl!
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions Inc. All rights reserved.