View Full Version : Color Transparency Exposure

Bob Phipps
8-Jun-2004, 10:09
Hi, As a beginner to 4X5, I have tried B/W [Agfa APX]and color transparency {Fugi Velvia & Velvia 100F and E100VS]. My Sekonic 508 is used for exposure readings. The B/W exposure seems to come out okay, but color trans. is terrible. Generally under exposed. What am I missing? I meter for the high lights as I would in 35mm and 120. I have dropped from f45 back to f32 or f22 and still get under exposure. Perplexed. Bob

Edward (Halifax,NS)
8-Jun-2004, 10:18
When you figure it out, let me know too.

Matt Miller
8-Jun-2004, 10:29
Maybe your shutter is slow. It could be & you just don't notice it in the B&W negs.

Edward (Halifax,NS)
8-Jun-2004, 10:34
Matt, if that were the case it would be because I am counting too fast (which is possible) because most of my exposures are in the 2-30 second range. And no, it is not reciprocity. I am using the 100F line of Fuji films.

donald johnson
8-Jun-2004, 10:38
I agree with Matt. I bought a shutter tester from Calumet, and 5 out of my 6 lenses were slow, sometimes by as much as more than a full stop, at the highest (1/125 and up) settings. Curiously, the slow speeds, which everyone is always concerned about, were all within 1/3 stop.

Gem Singer
8-Jun-2004, 11:01
Hi Bob,

If your shutter is too slow, your trannies will be over-exposed. It's possible, but not very probable, that your shutter is too fast, leading to the under-exposure you are experiencing. Simply changing the aperature won't solve the problem unless you also slow down the shutter speed. You probably are rating the speed of your color transparency film too high. Try rating it at a lower speed.

Try spot metering on an 18% gray card, or a middle gray area, instead of the highlights. Then, check the brightness range to make sure it isn't too high for transparency film. Jack Dykinga gives a clear description of this metering procedure in his book "Large Format Nature Photography".

Dan Fromm
8-Jun-2004, 11:23
Eugene has the answer, if not the analysis. If you meter the highlights with a spot meter it will pick an exposure that puts them at mid-grey. Then everything darker will come out, well, darker. That's nearly everything else in the frame.

That your meter wants f/45 may be a tipoff that something's wrong. At what shutter speed does it want f/45 with your ISO 100 films? Come to think of it, what shutter speed are you using at f/22? If faster than 1/50 (right to one stop under as implied by sunny 16 in normal lighting out-and-about) you're almost certainly guaranteed dense transparencies.

It is also possible, as he suggested, that you inadvertently misled your meter by setting a speed higher than the film's speed. I sometimes do that with my main meter, find the mistake when checking with the backup or when the main's recommendations seem, um, out of line with conditions. Its always painful.

Incident metering doesn't always give the right answer, but by george it yields consistent results.



Danny Burk
8-Jun-2004, 11:44
Are you getting satisfactory results with smaller formats? If so, try shooting a test subject on 35mm or 120 at a certain aperture/speed (say f/22 at 1/30 or whatever suitable exposure may be at the moment), and shoot the same settings with the same film on 4x5. You should get equivalent results unless your LF shutter speed is off.

Kirk Gittings
8-Jun-2004, 12:18
I recently was in the market for a new meter because I dropped my Pentax Digital Spot. I was also thinking of getting a newer design. I tried a few of the Sekonic models (4 newish or brand new) which were available thru a friend of mine who was reviewing them and the local camera store. Everyone of them overestimated the light levels by 2/3 to a full stop on the spot meter setting, which would result in over exposure unless you had determined a personal EV. These were mesured against a borrowed Pentax Digital Spot Zone VI Modified that had been recently calibrated by Calumet.

This seems very odd and I can't explain it. Jorge has suggested that the spot meter on the Sekonics is calibrated to 12% grey rather than 18%?

The net result is that I bought the Zone VI modified and sent my broken one in to Calumet to be repaired and modified.

8-Jun-2004, 13:27
I have a similiar problem when shooting color transparencies with my 8x10 (i shoot BW 95% of the time). My BW shots i meter with a spot meter and use the zone system and they seem to come out pretty well. When i shoot 8x10 transparencies they are almost always way too dark, so for transparencies that would be over-exposed would'nt it?

Stan. Laurenson-Batten
8-Jun-2004, 13:38
Good advice above but. The problem is that different people use different values to take readings. One man's highlight is anothers midtone. However, by using the 18% reflectance aid you can be sure that you will get the optimum exposure value for the scene every time. Again, but. Remember that there is considerable difference in the latitude of meduim and slow colour film. So, where it may be possible to get away with a slight under or over exposure in B&W negs. or trans. with colour film, particularly reversal and slow colour,such deviation from the optimum would be disasterous.

Bob Phipps
8-Jun-2004, 14:38
Thanks all, At f45 the shutter was 4 - 8 secs. At f22 the shutter was 1/10 sec[?] I think. Who is good at checking the shutter speed for a Nikkor 150mm f5.6. I am using this with a Toyo 45CF. The camera is great for the landscapes that I do, really a weight saver. Bob

Keith S. Walklet
8-Jun-2004, 14:41
Color transparency generally has a much narrower latitude than print film. Effectively 4-1/2 to 5 stops only. In a high contrast scene (full sun midday), you may not be able to get the full tonal range you have come to expect with B/W negative film, hence the saying, "expose for the highlights and pray for the shadows." Accessories such as neutral density filters (to knock down the highlights) or flashes (to open up the shadows) help to effectively narrow the overall scene brightness range from brightest highlight to darkest shadow, but are not always a complete solution.

And different films handle contrast, well, differently. Velvia is notoriously high contrast to begin with, while 100F handles the higher contrast scenes more ably, at the cost of lower color saturation.

Since "film is cheap" and "being there is expensive", in addition to the aforementioned suggestions from other folks, you may want to do some film tests to see exactly how your film behaves and accurately determine where the highlight/shadow detail disappears.

There is a counterpart to the B/W Zone system for color transparency, with a slightly different approach. You essentially learn a vocabulary of colors; which colors are more flexible to under and over-exposure, and with that information are able to see where you have wiggle room in your exposure to get the most out of the film.

BTW, I have long used the Sekonic 775 as my spot meter. Recently I've been using a Canon EOS Digital Rebel as my meter. I take a digital picture of the scene with the same ISO rating and framing as I have set up with my 4x5, evaluate the histogram to make sure I got all the highlight and shadow information, and adjust my exposure accordingly. It works fabulously!

Steve J Murray
8-Jun-2004, 15:39
Bob, I think Eugene hit on the answer. Spot metering off a highlight makes it middle gray. Get an 18% gray card and meter a close scene, like your house,not a distant vista, and do an exposure. Also, try a landscape on a nice sunny day and use the "sunny 16" rule and compare it to what your meter is telling you. The average shot at noon on a sunny day should give you a good exposure for 100 ei film as: f45 at 1/15 =(f16 at 1/125).

Also, you note that you get a reading for f45 for 4-8 seconds,and for f22 it is 1/10? That doesn't make any sense. That's only two f-stops difference, and the exposures you give are 6-7 stops apart. Something is not adding up right. If 1/10 sec is correct for f-22, then f-45 should be about 1/2 second. If 4 seconds is correct for f-45, then f-22 should be one second.


Kirk Gittings
8-Jun-2004, 15:40
"Everyone of them overestimated the light levels by 2/3 to a full stop on the spot meter setting, which would result in over exposure unless you had determined a personal EV."

Sorry I meant result in underexposure!

ronald moravec
8-Jun-2004, 16:29
There is nothing like an incident meter. No guessing tones. Just make sure you meter the same light falling on the subject. I do use a Pentax digital spot meter where I can`t get to the right spot, like a sunset or stained glass windows. This is the same reason why most all electronic flash meters for studio use are incident types, with few exceptions.

All my leicas have calibrated shutters and meters, and I check the copals with the Calumet. I shoot transparencies, B & w, and color neg at rated speeds with NO problems. Although sometimes I overexpose b & w or transparencies and reduce development for contrast control. I`ll probably get a lot of flack on this, but calibrate your shutters, calculate bellows extention, and make sure you equipment is working up to snuff before you start telling me HP5 is 600 or 250or whatever. If E 6 highlighlites are right and shadow detail is present in the correct amount on negs for normal contrast scenes, then everything is correct.

8-Jun-2004, 16:34
one thing you could try would be to use the meter to get a rough exposure and then work towards the final with polaroid. some polaroid b&w films--like 55 p/n have a pretty short latitude (in the positive) and make good proof films for chrome. where I work, we shoot mostly fuji 100F at a half stop less than polaroid 55 pos. The exposure is based off the highlight detail--with the print backlit (some call this "candling") to view the shadow detail. The neg is used to check fine-focus. after awhile, you'll get a feel for what the proof needs to look like to get the chrome how you like it. the 100 speed (coaterless) polaroid is good film for this too--but in the end, this stuff only works if your process remains consistent, so my advice would be to double up on your exposures, run half the film and then make adjustments to the remaining sheets if needed--or you can throw them away or have backup shots etc. you probably only need to think about bracketing a half stop or so either way depending on the subject matter.since you only have about 5 stops or less to work with, you'll see it in the polaroid. fwiw--I've proofed fuji 64T in 35mm by using the histrogram on a digital slr, and much to my surprise, it worked very similarly to polaroid....of course, with 4x5--it's great to use polaroid, because it's sitting there where the film is, and can be a real lifesaver sometimes....

Frank Petronio
8-Jun-2004, 18:08
I usually put the white fluffies at Zone 7.5 to 8 and let the rest fall where it may. Then I bracket three to five sheets depending on how strongly I feel about the subject. If I am organzied, I'll slightly underexpose three sheets, test one with normal processing, then push process the next sheet based on the test, with the third sheet for back-up or fine tuning. Works well with Readyloads and a Sharpie - hard to deal with loose sheet film on location without having a lot of boxes to segregate each shot (and a sharp assistant.)

And that is another reason why commerical photographers bring lights everywhere - gotta control the contrast.

Ben Calwell
8-Jun-2004, 18:26
I recently did a test shot of a building using Velvia 100F. The building is a sandy tan color. Using my old Pentax analog spot meter, I metered the building facade (which was in hazy sunlight) and placed it on Zone VI. I bracketed a third of stop on either side of the reading, and they came out beautifully. I checked my exposure by reading some gray cinderblocks, which fell on Zone V.

Roger Scott
8-Jun-2004, 18:42
Hi Bob,

It's always worth shooting a roll of 35mm or 120 (cheaper than sheets) on a film latitude test. You basically take a photo of a grey card (or something close) going from -5 to +5 in either 1/2 or 1 stops depending on how accurate you'd like to be. Although each film is different in general for transparencies you'll find the highlights blow out after about +2 stops and the shadows lose detail beyond -3 stops. In this instance if you meter from the highlights you'll need to adjust that reading by +2 for correct exposure. Of course if your shadows and highlights differ by more than 5 stops unless you're happy to lose some detail you're going to have to tweak something (usually with either grad ND filters or using a different film). The closer your subject is to the latitude of the film the more accurate you have to be. It's also worth taking note of the incident light - if you find your exposure differing by a stop or more it's worth checking things again.

Keith S. Walklet
8-Jun-2004, 18:51
Frank's method is similar to my own approach, passed along years ago by Pat Ohara. Using QuickLoad film, make three exposures at the same settings. Each of the three film sleeves is marked the same way, to indicate exposure, filtering, compostion. On a day where I create twelve unique images, that means 36 exposures.

When I get home I log the exposures in the order that I took them, numbering each in sequence. (Some folks number and letter such as #121-A, #121-B, #121-C but I've found just sequential numbering works just as well). Then I take one from each set of three frames (say frame A) to the lab to be processed normally.

Since some compositions are only slight variations on a theme, the lab needs to "twin check" the film with a pair of identical numbers (one on the film, one on the sleeve) in order to keep the film organized. That means in addition to my film, I get my sleeves back so I can match my notes to a particular image.

I then evaluate the exposed film. If it is off, I make an adjustment to the processing instructions for that image and send in the second (frame B) of the set. And so on.

If I get it right the first time, I have three well-exposed duplicate images. If I miss on the first frame, I have two more chances to get it right.

This is one of the real advantages to using single pieces of film, vs. a roll, and the reason I typically use the Quikloads (which are heavier) instead of loading my own film.

Jim Rice
8-Jun-2004, 19:10
Actually I'm throwing in with Ronald here, at least with regards to color tranny materials. An incident meter is the cheap/dirty WORKS way to go. I use a 30 year old Sekonic L-28 c2 that i bought new long long ago. I also rate Velvia at ei. 40.

Jim Rice
8-Jun-2004, 19:30
And congratulations, Frank.

Henry Ambrose
8-Jun-2004, 19:39
Bob, having your shutter checked is a good idea if you think it is off compared to a "known good" camera.

But more important -- test your outfit!

Go out with your 4X5 camera and 150mm Nikkor, pick an average kind of scene that is stable light wise, meter as usual, expose one sheet as metered with the meter set at manufacturers box film speed, then add one third more light to each succeeding sheet. For 100 speed film this would give the following settings on your meter for each shot: 100, 80, 64, 50, 40, 32. You'll end up with six sheets of film that will tell you most all you need to know about your meter, your camera, the film you use and the way you meter.

And for what its worth I've never found a transparency film that looks right without a bit more exposure than the box says. For me Velvia is 32-40, Provia is 64-80. You should test to get your own numbers.

Michael S. Briggs
9-Jun-2004, 06:40
What were the lighting conditions when you used f45 at a few seconds, and f22 at 1/10 s?

You can use the "Sunny 16" rule as a backup "sanity check". Somewhere on the web you will find suggested correction factors for various conditions, such as light overcast, heavy overcast, etc. Using these, if the extended Sunny 16 rule gives an exposure much different from your metering, then you are probably making a blunder.

You might consider using color negative film instead of transparency film. The exposure lattitude is much larger. This will help with small mistakes in exposure and also get better photos of subjects with a wide brightness range.

It is possible that the problem is the accuracy of the shutter speeds, but I think it unlikely. Obviously the few seconds exposure wasn't controlled by the shutter. Modern Copals are usually quite accurate. Finding a shutter to be slow at 1/125 or faster with the Calumet shutter tester is a red herring for two reasons. First, such fast shutter speeds are virtually never used in LF photography. Second, the shutter is calibrated in effective speed, and, most users of the Calumet shutter tester are probably measuring total opening time. Used in the obvious manner, the Calumet shutter testing starts timing as soon as the blades open. When the blades first open, the aperture is smaller than that set by the aperture diaphragm, so the total opening time and the effective time differ. This only matters for the fastest speeds, for which the travel time of the blades is important. This has been discussed here before.

Unless your desired depth-of-field requires f45, I suggest using wider apertures. Your image from a modern Nikkor will definitely be softer at f45 than at wider apertures because of diffraction.

Don Miller
9-Jun-2004, 07:13
It's probably something simple like bellows factor, big rise/ shift or similiar. Try testing with a simple distant subject. Have you read the exposure articles on this site? If you can expose velvia correctly with your other cameras (using the same meter) there's nothing much different with LF except what I mentioned above.

Most of us want to take the new camera out into the wilderness without testing/learning first. When that doesn't work well one ends up in the back yard doing simple tests.


Jim Becia
9-Jun-2004, 07:18

As a 508 owner also, I can tell you that I have to rate my Velvia at 32 and my E100VS at 64 to get the exposures that I consider correct. It seems that the meter is calibrated differently. Oh, I have a friend with one also, and he, likewise, has to rate his film at these numbers to get a proper exposure. Jim

Keith S. Walklet
9-Jun-2004, 09:36
Another factor in the film evaluation equation is whether or not you have a proper light table. Ideally this should be rated at 5000 K.

Mind you, illumination often varies across the surface of the light table depending on where the bulbs are. For critical evaluation and consistency, you should identify the sweet spot on your table and do your evaluations there.

tim o'brien
9-Jun-2004, 16:42
After reading all these great answers, my question Bob is... What do you mean under-exposed? Is the tranny dark or light in respect to what you expect?

tim in san jose

Frank Petronio
9-Jun-2004, 20:33
Another meatball way that I use for color (and for B&W portraits) is to meter my hand. The inside of my palm is Zone 6.5, the tanned backside is Zone 5.5. I'm a dark Italian - your mileage may vary. Get's you in the ball park and is good when the highlights go specular (like water reflections) and are just going to blow heck outta the highlights out anyway.

Ansel is spinning in his grave...

Bob Phipps
9-Jun-2004, 21:40
Thanks All, Great suggestions. After 35 years working professionally in 35mm and 120 text, card, and calendar sales with Nikon and Bronica, it just seems strange that I cannot get trans with images light enough to see. Most of the trans are 2 to 3 stops under exposed [dark] {for Tim's question}. I've used "Sunny 16", considered the bellows factor for a close-up. Scenics have ranged from gray overcast rain to full sunlight. I use the light boards ranging from 16X20 to 4'X5' with color correct bulbs. Could not stay in business without them. This has been a real problem. I guess trying settings to match the F5 would be a start. The film ratings I'll try too. Thanks for the help and suggestions. My reason for expanding to 4X5 is to open another area of sales - wall paper murals. Bob

Roger Scott
9-Jun-2004, 22:25
Hi Bob,

One other thought which I hope won't offend - are you loading the film around the right way in the holder? Assuming the metering is correct, the shutter is reasonably accurate and you're taking into account bellows factors it's about the only other thing I can think of.

10-Jun-2004, 09:23
2-3 stops under is alot for chrome film. even if your shutter is off, it doesn't really matter as long as it's consistent. again, this is where shooting some polaroid would be really helpful. at the very least it would narrow down the problems to either the camera or the film/process.