Test strip method

reub2000 · Feb 2, 2007

I'm curious to find out how my fellow apugers create test strips.

I find graduated test strips to be off little use. Each separate area is usually too small to evaluate, and often doesn't contain a full range of tones. Instead I rip off 1/3rd of a piece of paper, and guess the exposure. Then I go from there, exposing more test strips, until I have a time and contrast filter that works.

Steve Smith · Feb 2, 2007

Usually, I can estimate fairly well based on what I have done in the past so I cut a piece of paper about 3" square and place that in an area with a good range of tones, expose it and process it. I will then make additional tests on similar sized pieces depending on the results of the previous tests.

I will then do a test strip based on my results (though not always). i.e. if the 20 second test is too light and the 30 second test is too dark, then that is the range that the test strip will be in.

Steve.

ijsbeer · Feb 2, 2007

I've got a teststripmaker from Kodak. You must expose it for 60 seconds and develop, then I think in half stopts to get more black or white. When ive got the oxposure pinned down I'm gonna concentrate on the contrast. Mostly I make a few small testprints with different contrast settings. But with experience (wich i have not much of) i can guess in the direction of the good contrast setting.

Ijsbeer

Nick Zentena · Feb 2, 2007

For B&W I use spilt filtering. My test "strips" work fine. The first one gets me the yellow filter setting. The second one the magenta. Then a test print with both. Giving me exposure and contrast.

With colour I like the magic black box figure out everything.

Chuck_P · Feb 2, 2007

In split grade printing:

For the "soft" test, filter #0: I make sure the test strip covers the most important highlight where I wish for there to be detail present and the shadow area where I made my low value placement on the gray scale. The high value area is usually in a zone VII/VIII area. Not necessarily the area where the brightest whites are; the exposure shouldn't be based on full white areas, zone X, because adding more exposure to them will just make them a muddy gray.

For the "hard" test, filter #5: I place the test strip over the exact same area as for the soft test and make my exposures. Usually, I base the hard test exposure time on the appropriate contrast that keeps my low value placement where I invisioned it when I exposed the negative.

This gets me to my #0 and #5 exosure times by which to make a straight, unmanipulated print. Essentially, I'm working toward an unmanipulated print that holds my low value placement as true as it can while exposing the important high value area properly to hold that as true as it can. Then, of course, the dodging and burning begin from there.

Chuck

reellis67 · Feb 2, 2007

I use test strips. I have a good idea of where to start just based on the image on the easel, but I make a strip of 10/20/40/80 and that gets me in the range. Then I make a test print of the entire print and usually make a minor adjustment off of that based on the most important areas. For any given print I tend to make 1 test strip and 1 test print and then I work with dodging/burning, flashing, etc... from there if needed. In the beginning I used more test prints than I do now, but that was because I was not very good at recognizing the effects of exposure changes.

I also have a neat little device that I just picked up the other day - an Ilford EM-10. I have only used to for resizing known good prints so far, but when I have time I plan on trying to use it to eliminate the test strip stage.

- Randy

Neal · Feb 3, 2007

Just used test strips last night. 5 second exposures in 4 strips.

Neal Wydra

telkwa · Feb 5, 2007

i'm pretty good at guessing contrast, so ignore than for now.
i'll test strip different tonal sections independently, then guess for a final print as follows:

i'll do a test strip for the important shadows, a test strip for the important highlights, and a test strip for the mid-tones. each test strip is quite small, and i 'll usually give the mid-tones exactly what my test strip showed then dodge/burn the shadows and highlights if they needed time differs from the mid-tones.

MurrayMinchin · Feb 5, 2007

I use big and beefy test strips that hold lots of information from important parts of an image.

I've figured out the max-black times (the exposure time just before a clear negative prints as max black) for a range of contrast settings, so let's say I was doing a test strip for 'normal contrast' which has a max-black time of 18 seconds. I would go 15sec +2+3+4+5+6 for exposures of 15, 17, 20, 24, 29, and 35 seconds. This gets my foot in the door, and gives ballpark estimates for things like burning in a sky.

Later strips can be closer times, or single exposures.

I also write what contrast settings and what development time, if different than normal, in pencil on the back of the strip. After making a whole mess of them I can fish them out of the holding tray and compare them...how do you know you've gone far enough, if you haven't gone too far and then back tracked?

Murray

Roger Hicks · Feb 5, 2007

Steve Smith said:
Usually, I can estimate fairly well based on what I have done in the past so I cut a piece of paper about 3" square and place that in an area with a good range of tones, expose it and process it. I will then make additional tests on similar sized pieces depending on the results of the previous tests.

I will then do a test strip based on my results (though not always). i.e. if the 20 second test is too light and the 30 second test is too dark, then that is the range that the test strip will be in.

Steve.

Dear Steve,

My wife and I do something very similar. Some of the other suggestions look fantastically complicated.

Cheers,

R.

Lee L · Feb 5, 2007

I didn't like doing equal step test strips because the difference between steps becomes minimal at longer times. So in the mid-80's, before I'd heard of f-stop timing, I adopted a method using the Fibonacci series, which gives steps of just over a half stop. The series is generated by adding the most recent two numbers to find the next in the sequence, and gives a ratio between numbers of about 1:1.6, near the "golden ratio". The sequence goes:

1 1 2 3 5 8 13 21 34 55 89 ...

I worked out a way of using this for test strips using a metronome and a card to progressively cover up the paper. You can't go straight through the sequence, but can decide on the number of seconds in the series you want for your minimum and maximum exposure strips, then easily build the sequence from there. I'll just put two examples here so you can see the pattern needed to get a properly stepped sequence.

This sequence: 2 1 2 3 5 8 13 covering the paper as you move through the sequence yields a test strip with exposures of 2 3 5 8 13 21 34 seconds.

If you want to start with 5 seconds as the minimum, use 5 3 5 8 13 21 34 to build exposures of 5 8 13 21 34 55 89 seconds.

The trick is to start at your chosen base time, then drop one number from that in the Fibonacci series for the second strip, then start back up. With a metronome or beeping timer, you can easily count seconds for each step and then move the card, as the sequence isn't hard to memorize or post where you can see it.

Once I'm used to a particular enlarger/paper setup, as when I worked putting out 2000 custom B&W prints each month, I would only use this method to "bracket" around what I estimated by eye to be the best exposure for a negative that looked problematic. In that situation, it also helped to use only Fibonacci numbers because it simplified my work, and I could duplicate a print very accurately if someone came back for more copies.

Lee

ooze · Feb 5, 2007

I find an area which I think is important and contains a good range of tones. Then I use several strips of paper (sizes depending on the size of the area), and expose all of them around a guessed exposure time, which comes from past experience. For example, if I think that the print will need around 15 seconds, then I will usually use either 3 strips with exposures of 10s, 14s and 20s, or 4 strips with exposures of 10s, 13s, 16s and 20s. If I'm pretty sure that I'll need 15 seconds, then I may make strips of 13s, 15s and 17s. If it's an unusually dense or light negative I may expose a single strip with a considerably longer or less exposure time to get a rough idea and than continue from there.
The main idea is that I expose strips of paper over an important part of the image. The details may change according to the kind of music I'm listening to

Cheers...

jstraw · Feb 5, 2007

In this thread:

(there was a url link here which no longer exists)

I describe how I combine f-stop printing and split-grade and how that's managed in terms of test strips. I have some scans there of the test strips, labeled with times.

Blighty · Feb 5, 2007

Roger Hicks said:
My wife and I do something very similar. Some of the other suggestions look fantastically complicated.

Wonder what Roger would make of my method? I split-grade print (most of the time). For the soft exposure I make a test strip based on an important highlight but instead of moving a card across the paper, the same highlight area is given a series of gradually increasing exposures on the one strip. This obviously means masking off the already exposed segments. Once I've found the correct soft exposure, I make another series of tests with an increasing hard exposure (with the soft exposure on top), again on a particular area of print. Sounds complex but isn't (honestly).

ChuckP · Feb 5, 2007

Years ago I built a device that has a 1 in opening and allows a piece of paper (up to 8x10) to be slid along under the opening. I normally slide a 4x10 piece giving me 9 different exposures of the same area. I try to find a place that has both highlight and shadow so I can get some feel for contrast. The thing makes it very easy to find the best exposure point for the look you want. Downside is each new exposure starts from zero so it takes more time. I'd be lost without this thing.

timbo10ca · Feb 5, 2007

Chuck1 said:
In split grade printing:

For the "soft" test, filter #0: I make sure the test strip covers the most important highlight where I wish for there to be detail present and the shadow area where I made my low value placement on the gray scale. The high value area is usually in a zone VII/VIII area. Not necessarily the area where the brightest whites are; the exposure shouldn't be based on full white areas, zone X, because adding more exposure to them will just make them a muddy gray.

Chuck

Why do you have the low value area as well? Is it to get an idea of the density you're going to see there with just the yellow filter, so you can subtract a bit of time from your "ideal" Magenta time on the 2nd test strip?

Tim

timbo10ca · Feb 5, 2007

Blighty said:
Wonder what Roger would make of my method? I split-grade print (most of the time). For the soft exposure I make a test strip based on an important highlight but instead of moving a card across the paper, the same highlight area is given a series of gradually increasing exposures on the one strip. This obviously means masking off the already exposed segments. Once I've found the correct soft exposure, I make another series of tests with an increasing hard exposure (with the soft exposure on top), again on a particular area of print. Sounds complex but isn't (honestly).

When I learned split grade printing, I was told to do Magenta first, but it didn't really mater. To me it makes more sense to do the yellow first so you can have this base exposure present in the shadows from the yellow, then test stip with magenta to find the ideal time for shadows- Is this what you are suggesting here? Does yellow filtration have more of an effect on shadows than magenta has on highlights? Seems to me, either way you do it, there will be at least a little bit of density added either way, and you therefore have to drop your time a little bit from whichever you test first???? ARRRRRGHHHH- circular.. argument... brain...about .....to....explode....

Last night, I actually ran into this problem a bit. I had a low contrast neg, and I was under the impression you only really split grade for contrasty negs. Well, I found my contrast I liked (grade 4) for my dark regions ( a tree), but the snow and sky were completely burned out. So I added some time with 200 Yellow to bring out the density in the highlights. But this made my shadows go too dark, so I backed off a couple seconds on the magenta exposure. Finished product was to my liking. Is this a standard practice among others, because when I learned split grade, they said to dial in max Magenta...... I feel this would have been too much contrast in my print though.... or does the 200 Yellow balance it off? (sorry- a bit off topic).

Tim

Chuck_P · Feb 5, 2007

timbo10ca said:
Why do you have the low value area as well? Is it to get an idea of the density you're going to see there with just the yellow filter, so you can subtract a bit of time from your "ideal" Magenta time on the 2nd test strip?

Tim

Tim,

I include the important low value when possible in the "soft" test so that I can see all the detail that is present on the negative in that area. A soft test of the important low density areas of the negative can reveal detail present, and this gives me an idea of how much "hard" filtration I need to fulfil my original visualization of the low value placement---I find this most helpful when I have made low value placements at Zones I and II. It's hard to provide such an answer without the ZS verbage, but it fits, and I have found that it works.

Chuck

timbo10ca · Feb 5, 2007

Chuck1 said:
Tim,

I include the important low value when possible in the "soft" test so that I can see all the detail that is present on the negative in that area. A soft test of the important low density areas of the negative can reveal detail present, and this gives me an idea of how much "hard" filtration I need to fulfil my original visualization of the low value placement---I find this most helpful when I have made low value placements at Zones I and II. It's hard to provide such an answer without the ZS verbage, but it fits, and I have found that it works.

Chuck

Chuck- makes perfect sense. Thanks.

Tim

Blighty · Feb 6, 2007

Hey Tim! Sorry I should have also added that I find an area of the image that has highlight and shadow information. I don't always do the soft test-strip first. If the neg is soft, I find it much easier to do a 'hard' test-strip first, to find the best overall contrast, and then add what little soft exposure is needed. Sounds arse over tit, but it works for me!

Blighty · Feb 6, 2007

Tim,
I should add that many times I am faced with this problem of having a soft exposure 'leech' into the shadows, making them mushy. The great beauty of split-grade printing is that it allows me to dodge those shadow areas during the soft exposure and therefore alter the soft/hard exposure ratio to give me the effective grade required.

timbo10ca · Feb 6, 2007

Blighty said:
Tim,
I should add that many times I am faced with this problem of having a soft exposure 'leech' into the shadows, making them mushy. The great beauty of split-grade printing is that it allows me to dodge those shadow areas during the soft exposure and therefore alter the soft/hard exposure ratio to give me the effective grade required.

Makes sense, but I was under the impression that the major benefit of split grade printing is to minimize the need for dodging and burning, especially when there are difficult areas to address.

Tim

Chuck_P · Feb 6, 2007

timbo10ca said:
Makes sense, but I was under the impression that the major benefit of split grade printing is to minimize the need for dodging and burning, especially when there are difficult areas to address.

Tim

Tim,

I want the best straight print that I can possibly produce and that is only possible by well controlled film exosure and development. This is leading me to say that, IMO, properly exposing and developing your film is the single best way to minimize the need for dodging and burning during the printing process. If you find that you are consistently relying on excessive dodging and burning for final print value control, then I would rethink how I am exposing and developing my film. That old saying of "expose for the shadows and develop for the highlights" is as true a statement as there ever was in black and white analogue photography. I have found that my dodging and buring are so much more productive since I have a firm grasp on my film and development procedures---in other words, my straight prints are pretty good as they go, but they always benefit from additional value controls such as the dodge and burn, toning, etc...

IMO, the major benefit of split grade printing is best stated by quoting from Steve Anchell's Variable Contrast Printing Manual: it can "enable the printer to maintain precise control over the final image by observing and making incremental separate adjustments to the shadows and highlights."

Regards,
Chuck

Blighty · Feb 8, 2007

Chuck1 said:
IMO, the major benefit of split grade printing is best stated by quoting from Steve Anchell's Variable Contrast Printing Manual: it can "enable the printer to maintain precise control over the final image by observing and making incremental separate adjustments to the shadows and highlights."

Well I never read Anchells book, but his quote sums up perfectly what I like about SPG.

erich potgieter · Feb 17, 2007

Blighty said:
I split-grade print (most of the time). For the soft exposure I make a test strip based on an important highlight but instead of moving a card across the paper, the same highlight area is given a series of gradually increasing exposures on the one strip. This obviously means masking off the already exposed segments. Once I've found the correct soft exposure, I make another series of tests with an increasing hard exposure (with the soft exposure on top), again on a particular area of print. Sounds complex but isn't (honestly).

In "Way Beyond Monochrome" by Ralph Lambrecht and Chris Woodhouse (excellent, by the way) there's a description of a hinged test strip printing frame that allows you to do exactly what Blighty describes here. I had a lot of fun making this out of really heavy cardboard (they suggest "1/4 inch opaque plastic sheets"). It allows for 10 one-inch-wide strips across a piece of 8x10 paper, and I use 1/4 stop exposure increments.

This book also got me hooked on split-grade printing, so I follow the same process that Blighty describes. The only thing that's a bit painful for me is switching from grade 00 to grade 5 filters between every strip, when you're overlaying the hard exposures on top of the soft one - I initially thought, no problem, do all the soft ones first and then the hard ones, but this causes registration problems because you're moving the paper for each new strip.

(I also guess that this sounds complicated, but it isn't really - just slow.)

My only criticism might be that the one-inch strips are a bit narrow - I might make another frame with two-inch-wide strips.

Test strip method

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