test strip methods

[Michael R]

There's nothing primitive about simple test strips. Evaluating them is another matter, and will improve with experience. I don't state this as a default method. I do have very sophisticated options, including a very precise easel densitometer, full feedback colorhead circuitry, and tons of experience doing densitometer plots and even inventing special math formulas related to all this. These did have a purpose with respect to sophisticated color printing strategies using multiple precisely matched steps. But for simple silver gelatin printing, or even basic RA4 color neg printing, test strips are the straightest route from Point A to Point B. And I'm about as nitpicky as they get when it comes to print quality. Why make it harder than it needs to be?

I just slice off a strip of the printing paper two or three inches wide, place it in an appropriate position in the easel, and then section off the increments using a big sheet of cardboard. A typical example might be 9 / 12 / 15 / 18 seconds at f/11 - all depending of course on the specific paper, enlarger lens choice, degree of enlargement, and particular light source I'm using. Then after development, I squeegee off the strip, and dry it for about 20 second in a little nearby toaster oven, and examine it in what is equivalent to display lighting. And I factor in the supplemental contrast deepening due to post-toning. But due to sheer experience working with particular papers, often I bypass the dryer step. The real litmus test is the following day, seeing with fresh eyes the full air-dried print itself, toned n' all.

Drew, I agree completely B&W tests strips/prints made using basic/simple methods tell us all we need to know. But what are these fancy math(s) things you invented? I hope they were not based on the work of that friend of yours who figured out how to accelerate particles to >c

[Drew Wiley]

Well, my friends up at LBL have all retired, and had some staggeringly fancy equipment to worth with. Just solid gold target in that >C case was the size of a brick - so go figure the overall budget. I don't personally have any interest in counting muons or quarks or Mr. Higg's mini-bisons. But I do have a densitometer that reads as precisely to .01 density, along with a basic ten buck log calculator. That kind of stuff was all used in relation to establishing certain very tight lab film protocols. But once thoroughly plotted and accustomed to, it didn't need to be used again every time. I have less math memory than a Planaria having trouble dividing into two, so wisely wrote my own little owner's manual. It's helpful when I actually need to go analytic, mostly in relation to sophisticated color printing controls. I never bother with that stuff in ordinary black and white work.

But it does explain another reason for me touting TMax100, due to its excellent highly-predictable batch to batch quality control.

I presume you are contemplating a new career in quantum computing now that the air temperatures up there are approaching absolute zero. Or has global warming spoiled at that?

[Fred L]

Test strips are just a beginning to homing in on paper contrast and exposure. Once I have a beginning exposure and contrast grade that seems appropriate, I jump to whole sheets of paper, and optimize exposure/contrast, and dodge/burn.

E v e n t u a l l y, I end up with the print that I like.

yup, pretty much describes my process. Sometimes I may adjust contrast if the full print needs it. but otherwise...

and I always place the test strip on the most important part of the image.

[Doremus Scudder]

Test strips are just a means to get a ballpark exposure for a test print.

It's really the first full straight print (or one with an initial trial dodge/burn scheme) that tells the tale.

So, find an important highlight area, place your test strip there, make strip with wide-enough and evenly-spaced-enough increments to give you the information necessary to decide on base exposure for your test print.

Some things that help me:

I make proper proofs of all my negatives (that's minimum exposure for ~max black for the film rebate at my chosen "standard" paper contrast). These give me information about starting contrast setting for the test strip. They also serve as a control on my film exposure and development.

If my test print isn't the contrast I want, I change contrast settings and make a new test strip. Trying to save time by guessing the exposure change needed when switching contrast settings significantly just wastes paper. Similarly, if my initial test strip doesn't have full information and a too dark and a too light stripe, I'll make a new one at a different exposure instead of guessing.

I hang up my test print made with the contrast setting I want (close, at least). Let it dry completely and spend time examining it under the viewing lighting (a mix of daylight and tungsten lights at an illumination level I consider average gallery lighting). My motto here is "waste time, not paper." I sit with my legal pad and come up with a strategy for dodging, burning, exposure changes, split-grade manipulations, etc. Maybe I'll even bleach an area of the test print to see if that is something I want to work into the mix. When that's all done and decided...

...I'll make my first work print. This one with all the manipulations and changes I've planned. From there on, it's dry, view, strategize, make another work print, till I've reached the stage of fine prints.

Then I'll make a couple slightly different in contrast/exposure/whatever so I can choose the best. This is a bit of a ring-around to home in on the best of the best. Often, more than one of these will be keepers. Then I'll make another one or two (more if the print's really difficult, so I have some stock) to keep in storage.

The test strips, get me quickly to the work print. The time is spent after that step.

FWIW, I make strips by leaving the enlarger light on the whole time and progressively covering parts of the strip. I time with a metronome and keep count in my head (trained musician here; used to counting). My test strips are in 30% increments (kind of like f-stop timing, but without the pesky calculations). I like exposures in the 15-30-second range, so my test strip looks like: 10 sec., 13 sec., 17 sec., 22 sec., 29 sec., 38 sec. (count is: 10-3-4-5-7-9, approximate but close enough and easy to remember). I'll extrapolate intermediate exposure from this if one stripe isn't exactly right.

On a peripheral note: I don't understand all the negative comments about developing in tubes. I develop in trays, but certainly don't do any manipulations to the print while it's in the developer; just agitate and develop for the proper time. Tubes will do the same thing. There's not much you can do with a print while it's in the developer except extend or shorten development time, and that's really not a good solution nor a substitute for getting print exposure right. Tubes should work just fine, even for beginners.

Best,

Doremus

[Pieter]

Test strips are just a means to get a ballpark exposure for a test print.

There's not much you can do with a print while it's in the developer except extend or shorten development time, and that's really not a good solution nor a substitute for getting print exposure right.

+1

[Drew Wiley]

I have a high rate of success going straight from test strip to final. "Work prints" are what I would otherwise term trashcan "duds". A few are inevitable, especially if a complex dodging/burning sequence is called for. But for me, they're more the exception than the rule. Good paper is getting darn expensive. "Inflation" is an understatement. ... So, I'm perfectly happy to break the "rules" in order to conserve paper, like recognizing variable development time for what it really is - another highly useful tool.

[Doremus Scudder]

I have a high rate of success going straight from test strip to final. "Work prints" are what I would otherwise term trashcan "duds". A few are inevitable, especially if a complex dodging/burning sequence is called for. But for me, they're more the exception than the rule. Good paper is getting darn expensive. "Inflation" is an understatement. ... So, I'm perfectly happy to break the "rules" in order to conserve paper, like recognizing variable development time for what it really is - another highly useful tool.

I think variable development time is, indeed, a useful tool. I just can't seem to plan on it from viewing a test strip

It's not often I can arrive at a final fine print on the first take after the test strip. If you're doing that consistently, you're a better man than I am, Gunga Din!

My trash can is my best tool.

Doremus

[Torquemada]

I think variable development time is, indeed, a useful tool. I just can't seem to plan on it from viewing a test strip

It's not often I can arrive at a final fine print on the first take after the test strip. If you're doing that consistently, you're a better man than I am, Gunga Din!

My trash can is my best tool.

Doremus

enlarger paper makes wonderful kindling paper.

[Tin Can]

I learned test strip MUST be from same box of paper.

Slowly

[Michael R]

I think variable development time is, indeed, a useful tool. I just can't seem to plan on it from viewing a test strip

It's not often I can arrive at a final fine print on the first take after the test strip. If you're doing that consistently, you're a better man than I am, Gunga Din!

My trash can is my best tool.

Doremus

I think you’re in good company, Doremus. Anyone interested in making great prints ought to familiarize him/herself with the trash can. In fact I’m surprised no one has yet decided to sell split grade or f-stop trash cans.

I sort of agree regarding print development “controls” - not that I agree it’s a useful control but the part about how to use it. Look at a test strip and decide it needs adjustment, make the decision the adjustment will be via altered print development, and then what? What change do you make? Unless beforehand one has done some sort of controlled, comprehensive series of “tests” of a particular paper/developer combination, how do you know what to do?