I love reading how everybody does their test strips. So much great information in here (and things I intend to try during my next session). Thanks to the OP for posting the question and thanks all for the wonderful answers...
I'm with you on this one, Mr. Carnie. I use half sheets (of 11x14 paper), eyeball it for a given density and move on from there. I usually have it close by the third piece. I tried test strips by they don't agree with my brain. I rather make the call from the complete image.
Originally Posted by Bob Carnie
I use a sheet or strip large enough that every segment will have both highlights and shadows.
Turn on the light, and count while progressively covering the paper.
I cover the first sector after 4 seconds, then 5 1/2, 8, 11, 16, 22, 32 and 45 seconds.
The first is almost white, and the last almost black. but there is a half stop between each segment, so if the correct exposure should have been 22 seconds, i can open half a stop and expose at 16 seconds, or a full stop and expose at 11 seconds, or close down in the same way to get 32 and 45 seconds.
This also tells me if I should use a harder or softer grade to get the mid-tones I want - if the steps are too easy to see it's too hard, if the changes are too week it's too soft.
-- Ole Tjugen, Luddite Elitist
I can appreciate how some may consider test strips a waste of time, especially if you've got a good handle on your printing process. Unfortunately for me, I started with a digital camera, and I've only been shooting film for the past year. In fact, I've been in the darkroom for only a few months! So while I get the hang of the darkroom, I'll probably want to stick to test strips while I work on getting a "feel" for printing.
In particular, I've liked the notes from Ole regarding determining the correct contrast grade, and samcomet regarding the relationship between stops and height of the enlarger.
At present I use a Kodak Projection Print Scale to determine the center point for making the standard test strip. http://www.flickr.com/photos/kb1awv/5357450760/
For example, if the Projection Print Scale reveals that after dry-down an exposure of 28 seconds would be a good general exposure I then make a normal test strip (card pulling) with set intervals above and below the 28 second exposure. ie; 24, 25, 26, 27, 28, 29, 30, 31, 32 seconds. These test strips eventually end up in a file folder w/notes for that print.
Last edited by anon12345; 01-28-2011 at 12:40 PM. Click to view previous post history.
Reason: spellin errors
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I have found a hot-glue gun and thin black foam-core or mat board (the cheap type that is opaque) to be ideal when making darkroom gadgets like test strip printers. A mat cutter makes quick work of cutting the bits to a precise size.
If exposure is correct, that gives you a base. Make one or more contacts changing exposure if you must.
Make your contact print at 8x height and and 8x10 will print at the same time/aperture. With 35 mm. 3.5x 5x 8x 11x and 16x progressively reguire double the time plus resciprocity compensation if you alter time.
Test strip is a narrow strip that spans highlight & shadow. A whole sheet is very expensive and you gain nothing. It does not matter the angle of the strip, just get it to cover the right places.
Lay a strip of cardboard down so you place it properly.
Trust me, sloppy exposures are expensive also. My contact sheets are all uniformly exposed. Saves a ton of time and expense.
Now we are talking , whole sheet plus out flanking.
Originally Posted by MaximusM3
I like your method: f-stop timing easily accomplished. I may adopt it myself, or some variant thereof. Don't know why I hadn't thought of something along that line already (even though working with percentages has always seemed logical to me).
I use a StopClock 500 (RH Designs) and I am happy with its f-stop test strip generation mode. You set the interval, I usually start with 1/4f for new negatives and 1/6-1/12f for ones I know, and just expose progressively shading more of the paper. I would aim for about 7-8 steps. When split-grade printing with this timer, I usually have two extreme grade strips done and evaluated in about 7-8 minutes and I can now move onto the fun part of working out the dodging and burning.
Last edited by Rafal Lukawiecki; 02-12-2011 at 12:57 PM. Click to view previous post history.