Film speed test.

[Heroique]

As [I’m] the OP, maybe some personal information and background would help. …I have the financial resources, but not enough time.

Then I’ll repeat my post #4 – I’d sacrifice testing on the altar of shooting.

More bluntly, get out there and shoot box speed. ;^)

Back home, your real shots can serve as “test” shots for future outings.

And down the road – when you do find more time – think how easy testing will be in the context of all your practical field experience!

[Robert Budding]

Robert - when you say that you wouldn't go out and shoot without testing first, what do you mean? What are you testing for? EI? Or how a certain developer will be different from another? How can you test that before you go out and shoot and process a bunch of film with it, so you can tell the difference?

I can understand testing because you want to fine tune your processes, optimize your exposures for a specific result with a specific film, or a certain look to your prints. What kind of a "quick test" would you do before you even go out and shoot?

I'm only asking this because I'm wondering what kind of test result would prevent you from losing shadow detail (or blowing highlights for that matter) in the negative that you wouldn't have done anyway? You probably already have a pretty good idea how much a given film can handle and how to meter the scene to avoid this happening. What more can testing tell you? (Unless mabe your main subjects are black cats in new fallen snow on bright sunny days, but that's not most people.)

It's an honest question - why couldn't anyone with a little fundamental knowledge and experience go out in the field and make a perfectly acceptable exposure without first testing something?

Or even more, how could someone without any experience go out and apply those test results with any success? Especially in the OPs situation, where he might lack the experience to properly meter a scene, or even be able to just look and know what might or might not work for a particular scene? What's he gonna do different with test results?

I think testing is important, and I did it even when I shot only roll film. I used to use HP5+ in D76 EI 200. That was based on running a film test to establish densities above BPF. Then I switched to XTOL and I found that I could hold shadow detail at EI320. I suppose that I could have shot at box speed initially, but then I'd have lost shadow detail forever. That matters to me, it may not to you.

For quick and dirty development times I make a few Zone VIII exposures and varying development time. A few densitometer readings and I can plot the Zone VIII exposure as a function of time (Pretty easy to pull that exposure down to Zone VI density for my N-2 or push it to Zone X). That gives me enough info to estimate where the various curves will lie based on development times. I could go whole hog and check my EI as a function of development time, but I've found that adding a bit of exposure when I think I need it is fine.

I could have eventually gotten to the same place without testing, but I'd rather no test on photos that I may actual want.

[Leigh]

Not if it's done in conjunction with exposing for the shadows and developing for the highlights.

Sorry, Neil, but you totally misunderstand my statements.

I'm talking about developing single sheets which were exposed under non-average conditions, either unexposed or very saturated (high density).

My point is that development times are based on the amount of developer that's used when processing an "average" scene. If the negative
does not exhibit that overall average density, you may get more or less development than anticipated in a particular amount of time.

The simple solution to this is to expose the negative properly, with select areas having the desired density. It's quite easy to shoot
a test target that has both white and black areas, and a number of gray areas, and has an overall reflectivity of around 18%.

This will yield results that most closely match those of a negative when you shoot a real scene.

- Leigh

[Kevin J. Kolosky]

I wonder what happened to Zones 0, 1, 2, 9, and 10.

[Robert Budding]

I wonder what happened to Zones 0, 1, 2, 9, and 10.

Two points determine a line, and I'm always operating on the linear part of the curve. So I find the other zones by using y = mx +b.

[Cletus]

Kevin - Most people don't usually express print tones in Zones 0,1 or 9, 10 as there isn't really any detail at those extremes and are almost indistinguishable from pure black or pure white (or each other). At least that's my understanding. And also my step Wedge tells me so!

[Kevin J. Kolosky]

"Two points determine a line, and I'm always operating on the linear part of the curve. So I find the other zones by using y = mx +b."

Perhaps you should try operating at the nonlinear parts of the curve just to see whats there. And if you want to use some math while your there you can take the derivative,

f' (X) = lim f(x+h) - f(x)

h - 0 ------------
h

to find the instantaneous rate of change or slope, although I don't know what good that would do for anything.

[Kevin J. Kolosky]

"Two points determine a line, and I'm always operating on the linear part of the curve. So I find the other zones by using y = mx +b."

Perhaps you should try operating at the nonlinear parts of the curve just to see whats there. And if you want to use some math while your there you can take the derivative,

f' (X) = lim f(x+h) - f(x)/h as h approaches 0
to find the instantaneous rate of change or slope, although I don't know what good that would do for anything.

[Robert Budding]

"Two points determine a line, and I'm always operating on the linear part of the curve. So I find the other zones by using y = mx +b."

Perhaps you should try operating at the nonlinear parts of the curve just to see whats there. And if you want to use some math while your there you can take the derivative,

f' (X) = lim f(x+h) - f(x)/h as h approaches 0
to find the instantaneous rate of change or slope, although I don't know what good that would do for anything.

I've done plenty of tests where I expose every zone that I'll use, and a few besides that. Like I said - I work on the linear part of the curve, so there's no need to test the extreme. I understand limits after taking 5 calculus classes in college. And I understand when they are completely and totally irrelevant.

[Kevin J. Kolosky]

"I've done plenty of tests where I expose every zone that I'll use, and a few besides that"

Good for you.