Well, sure. I just got back from the mid day dog walk, and it was -1F actual temp. But...if you're just running some tests, you can photograph out of a window.....Originally Posted by monochromeFan
Well, sure. I just got back from the mid day dog walk, and it was -1F actual temp. But...if you're just running some tests, you can photograph out of a window.....
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
monochdromeFan,
You've got the idea for the exposure basically correct. Two stops less exposure than the meter reads is either stopping down two stops or increasing the shutter speed two stops (note: you wrote "reduce the shutter speed," but changing from a slower 1/15 second to a faster 1/60 second is actually increasing the shutter speed). In either case, you are letting less light in to expose the film.
As for development: Development is independent of film exposure. Development determines the contrast gradient of the negative. More development = more contrast, less development = less contrast.
For a "normal" scene, you want "normal" contrast. You don't fiddle with development times when you change exposure; exposure depends on the lighting intensity for the scene.
Metering a shadow value is a good technique because it keeps you from underexposing in contrasty lighting and ensures you get the shadow detail you desire. The complication with metering shadows is that the meter wants to give you an exposure that will make what you are metering middle gray. If you want what your are metering to be a textured black, then you need to underexpose two stops from the meter reading to make that happen. This has nothing to do with your developing time whatsoever.
Either you have misunderstood Roger Lowe or he's wrong (I haven't seen the video).
The point of finding a developing time for normal-contrast scenes that prints best right in the middle of the contrast range of the VC paper you are using is so that you have room on either side of "normal" for the more- and less-contrasty extremes.
Clear now?
Best,
Doremus
I liked reading the David Vestal book, but it doesn't mention Zone System at all. He also didn't know what we know now about Selenium cell light meters. They are all losing sensitivity.
What light meter are you using? It might help us suggest exercises.
We're all teachers here and love to talk about Zone System because it's a great way to learn how Black and White film photography works.
The Zone System lets you look at any part of your subject and decide in advance how you want to see it on the print.
So far you've been talking about one Zone: Zone III - Dark gray/almost black. It's an important Zone to start with so always keep it in mind.
But the Zone System's true strength comes from the fact you can take any meter reading, of any part of the subject, and choose the shade of gray you want it to come out. It's about your intentions, and making them come to fruition.
For example, suppose you meter the whitewash walls of a church and want to make it come out almost pure white: Place the reading on Zone VIII (count from Zone V to VI, VII, VIII - and choose a base exposure 3 stops greater than the meter reading).
Hint: The resulting f/stop and shutter speed might very well be the exact same as you arrived at when you took a reading in the shade and "placed" it on Zone III.
In a Normal scene, every meter reading you look at and "place" on the shade of gray you would like... will arrive at the same f/stop and shutter speed.
If you treat everything as Normal and make compromises about some of the readings that don't fall where you wish... you can keep going with normal developing.
The next steps that you will eventually want to get into learning, are only necessary when you are unwilling to compromise. Then you may place one reading and decide development to make the other important tone come out the way you want.
But if everything falls naturally into a shade of gray that you can be happy with. You can go a long way with Normal.
Long ago & far away when I lived in Florida, Phil & I spent the morning (& afternoon) testing Xtol on every Kodak & Ilford film we could find. While walking out of the darkroom towards dinner, he spotted a box of Agfa 100 in my pack. Dinner was delayed another hour…
He sure taught me a lot on how & why the photo process actually works.
“You can’t have everything. Where would you put it?”
If the meter is the problem in cold weather then fresh batteries may fix things - just like an old car battery can't crank the engine when it is cold. Ditto cold lubricants in the camera can stiffen and mess things up.
Darkroom Automation / Cleveland Engineering Design, LLC
f-Stop Timers & Enlarging meters http://www.darkroomautomation.com/da-main.htm
https://www.largeformatphotography.i...s/ZoneDial.pdf
easy link from the website yeeeaasss..
if i understand it correctly,,
i take my light meter, set my film speed on it.
Take a reading of my important area, decide on my prefered aperture, thumb through the meters output until i find the aperture i want to use, and then see the suggested shutter speed.
Move the big dial so that the shutter speed number is under my chosen lens aperture.
See what EV number is on the V, and turn the number to my DESIRED zone, then go down to my aperture and see the new shutter speed.
I never understood the use of the Zone Dials. My Pentax digital spotmeter, and the analog one before it, don't have them. I simply take a reading, line up my desired aperture, and read the shutter speed. I know this is for middle grey so if what I metered I want to place in Zone III I simply reduce the exposure time two stops. If shutter speed is read to be 1/15, I will shoot 1/60. It's that simple. I usually only meter looking for deep shadows, shadow with detail, and then sometimes look for what "middle grey" is in the scene and maybe make sure that bright area with detail isn't going much over Zone VII or VIII. I'm pretty lackadaisical with my Zone process these days though and rarely ever do push/pull except in special situations.
This is almost exactly how I determine exposure as well. In practice, I don't need to get any more specific than that. And let's not forget, most modern films have so much latitude anyway, that errors (especially in the overexposure direction) have far less impact on image quality than they once did.
High performance films like TMax need careful exposure placement if you're going to get the most out of them. Relying on "latitude" is just looking for trouble. Yesterday I was out scouting in the rain with some Triassic X in my Nikon; so TTL metering based on Z III shadow placement in that moderate contrast situation was fine. But I plan to go back today with the 6X9 and TMX100, plus the spot meter, and I sure as heck am not going to waste any valuable real estate left behind down in ZII and ZI fudging the exposure like I can get away with using Tri-X for a more casual purpose, which will probably never get printed anyway.
Zone labels? One of my Pentax meters had one on it when I bought it, and I instantly removed it. What's the point? The engraved scale tells you everything you need anyway. That meter was almost brand new, and I bought it for a song. The same fellow was selling off his Sinar 8x10 and filmholders etc too - all seemingly unused. Maybe he kept the AA-wannabee Stetson cowboy hat. Dunno.
The "Zone System" is based on the principle of "expose for the shadows", and then "develop for the highlights." This offers two degrees of freedom for controlling the outcome of the negative. (Traditional B&W photography has only a single degree of freedom: take an average exposure of the scene and then develop film for the recommended time/temperature.) Thereby, the Zone Systems gives you greater control over the negative.
You have the first degree of freedom (expose for the shadows) described correctly: take a meter reading of a Zone III area of the scene, and then expose the film at two stops darker.
Your question about controlling contrast relates to the 2nd degree of freedom above: "develop for the highlights."
Sidestepping a lot of peripheral testing, a very good place to begin is the following. Set your ASA film speed at half the manufacturer's recommended speed. For example, if 400ASA is recommended, use film speed ASA 200. (Just about every time that I actually test for film speed of either MF or sheet film, it comes out at half the manufacturer recommended film speed.)
Then, determine the normal (N) development time to be that development time that renders a Zone VII area in the scene (on the negative) to be 2.35 density units . (This 1.35 is very close to the Zone VII value that John Sexton uses.) Of course, this requires a densitometer. But personally, I would never engage in zone system preparation without a densitometer. (I have a Tobias densitometer that works very well for me.)
One can set up a Zone VII area of the scene by illuminating a white card, set the exposure and aperture on the lens according to a meter reading (zone V) of the white card, and then expose the negative to this white card after first opening the aperture by two stops. Of course, this requires some trail an error by gradually increasing (or decreasing?) development time until 1.35 density units on the negative is actually reached.
Thereafter, the N+1 development time is that which yields 2.35 density units after increasing the aperture for the white card by only one stop. (Versus two stops.) N-1 development time is that which yields 2.35 density units after increasing the the aperture for the white card by three stops. Etc.
Once you have these development times, and possibly N+2 and N-2 development time, proceed as your Zone System book describes.
About the best book I've found on the Zone System is "The New Zone System Manual" by Minor/Zakia/Lorentz. Don't try to use Ansel Adams book "The Negative" to understand the Zone System. He pivoted on Zone V versus Zone VII, the latter of which is typically used in practice. I would also avoid using Fred Picker's book to understand the Zone System. He has some good testing in that book, but his book's description of the Zone System is at best clumsy and incomplete.
Added Later . . .
It's important to use daylight corrected (bluish color) bulbs to illuminate the white card. This is because black and white, panchromatic film, is daylight corrected.
Last edited by neil poulsen; 18-Jan-2024 at 09:16.
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