I'm a film testing moron- wadda ya think?
I undertook the endeavour of film testing a few months ago when I was only shooting 35mm, because I seemed to be underexposing everything using the film (FP4+) box speed and Ilford's development time for Ilfosol S (6 1/2 min). On the 35 mm frame, I came up with a film speed of ISO 64, but didn't get around to testing development time, as I aquired a view camera.
So, I've tried doing some 5x7 film (FP4+) testing using an "inspection" approach, as I have no densitometer. Essentially placing a dark cloth on zone 1, making 5 exposures and developing by manufacturer's recommendations (Ilfosol S for 6 1/2 min). Then using a 0.1 ND filter on a piece of developed unexposed film, comparing the 5 pieces to determine film speed. Here lies problem #1. For the life of me, I can't get a piece of film with equal density across it, so my comparisons are invalid. I don't think it's my developing technique, as I've developed a number of actual photos I've taken, and none are uneven. I actually have found tray processing of the film quite easy from the start.
To find development time, I made 6 exposures of a white wall placed on zone 8 using the "film speed" I determined in step one (I used the closest piece of film I could find in what I was already considering a flawed test- ISO 64). I developed the film and started removing pieces to the stop bath every 30 sec starting at 5 1/2 min. Next is a contact sheet made with half of each piece of film covered for the minimum time to achieve maximum black on the paper. Once dried, I am to inspect each interface on the paper where the film was covered looking for the faintest hint of tone, thus being Zone 8, and that piece of film was developed for the correct time. Here lies problem #2. For the life of me, I can't reliably see a faint trace of tone for *any* of these pieces of film. I can maybe convince myself that I saw a trace on 2 of the samples, so that would indicate a development time of 6 min at 20 deg C.
I tried some still life's of some flowers, and when I contact printed them, they were way overexposed, overdeveloped or both. I was also reading BTZS at this time, and was considering having the testing done for me. Before doing that though, I wanted to give it another try using HC-110 at 1:31. I had not been happy with Ilfosol's shelf-life. So, I did it again, had the exact same problems, came up with a film speed of ISO 80 (which I don't trust) and a development time of 6 1/2 min (which I also don't trust).
I'm pretty fed up with this scheme- I am obviously inept at something, because in all these books I've read, the authors make it sound so simple to set up a card and make the exposures, etc. This is very frustrating to me, because it all seems so simple, makes perfect sense to me in theory, and I work in a very methodical fashion. But my results are crap! I'm throwing the Zone System out the window once and for all, along with doing my own testing. I'll let the View Camera store do the testing for me. BTZS makes more sense to me anyway.
Just out of curiosity, what are other people rating FP4+ at and how long are you developing for in HC-110/ Ilfotec HC, and in Ilfosol S?
Why are you bothering to do this, especially if it all frustrates you? Some people love doing this stuff, and some people hate it (you it seems, and I as well). You can test to the moon and back but it's so much easier just shooting and fixing it as you go along. If you are paying attention (writing down your development times and iso)it takes at most 2 or 3 rolls (or sheets in your case) before you've got it down right. I had a couple assignments in school that dealt with curves, testing, plotting d log h log and i dont even remember what else. I've never used those skills since.
I'm sure someone reading this will laugh to themselves and mutter "amateur" but I don't think a great photograph from b&w negatives can be ruined by 30 seconds too long development or 1/2 stop too much or too little exposure. We're getting into OCD territory when we start worrying about this stuff.
go out and take some real photos, a stop either way is not gonna matter
Tim, I'm wondering how are you doing your metering? Dan
Haven't used Ilfosol S, but I used to get development times of around 6 minutes for HC110-B.
Originally Posted by timbo10ca
More to the point. After having gone the route you have (I used a spot meter in conjunction with the .1 ND filter to read through the filter/film sandwich on a light box when running the Zone I test.) I have, as of late, more and more found myself using an incident meter, even with my view camera.
My reasoning was this: with my medium format stuff, I'd been using incident readings just fine and getting very printable negs. If I was in doubt about a particular scene, I listened for the ghost of Ansel Adams whispering in my ear, "Bracket, dummy," and did so. Most all the negs are very printable.
Modern T-grain film, particularly Delta 400 and ACROS are very forgiving and don't respond quite as readily to N+ or N- development as older films anyway, so I'm finding that in at least 75% of cases when I'm shooting 4X5, I simply rate the film one stop lower, e.g. Delta 400 rated at 200, use an incident meter, and develop for the time that seems to give me the greatest number of good, printable (with full range of tones) negs. Since I have a Sekonic 508, I always have the option of the spot meter in those cases where I think I really need it.
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You can try the method suggested by the late Barry Thornton. You simply use your contacts to zero in on your EI and development times. Basically, you contact all your negs at the min-time-for-max-black at grade 2. It is then obvious if your shadows are too dark (decrease your EI) or the highlights are blown (reduce your development time) or vise-versa. This rather assumes that you are not using a condenser enlarger, but IIRC, there are ways to compensate for that if you are.
See www.barrythornton.com - Andy Hollingsworth is keeping the site alive - articles on Personal Dev Time, Personal Film Speed, UnZone etc (in fact read the lot ).
Good luck, Bob.
Your first test should be of shutter speeds and f-stops. It seems that the effective film speed you got with one camera doesn't work with the other. Maybe you should try using box speed with the first camera and assume that the effective lower speed was caused by the shutter, not the film.
There are several ways to check shutter speed. If you have a phonograph turntable you can tape a penlight to its outer edge, photograph it rotating and calculate the effective shutter speed by the angle through which the light moved. You can photograph a TV screen with your favorite show on and find how many scan lines show. Each method has its limitations, but if you find an error at one speed you'll get some idea of what to expect when you try to establish film speed. What I'm really trying to say is that the effective film speed you get for one camera is in fact not likely to apply to all cameras using that film, and may not apply to all shutter speeds.
The first time around I used a cardboard box- it didn't seem to work. That's why I switched the the black cloth (a bedsheet, actually). I pulled it taught and spotmeterd all over it, ensuring even illumination and no shadow thrown by the camera. I put the bellows to infinity focus and set the camera right in front of the sheet to make the exposures. I even took lens coverage into account, and made sure the camera was set at neutral (sounds inuitive, but I was trying to ensure all bases were covered). Obviously I'm making a fundamental error, but can't think of what it might be. The only things I can think of is if the lens is too out of focus, and causing flares or distortions (is this even possible?), and the fact that I cut the film sheets in half before loading the holders to save on film usage. They were definitely loaded properly with no chance for light leakage.
I think it's time to jump into BTZS with both feet and let them do my testing. I feel the need to do this because my brain and experience level don't allow me the option of fiddling until I get it right. As rjas sais- why am I bothering? Well, it's time for a new, less aggravating approach. If anything, it's been a learning experience. Thanks everyone for your input.
Tim, I have re-read your testing procedure, and I am horrified, I have absolutely no idea what you're doing!
I would second the Thornton method just to get you on your feet with good negatives and stop worrying about complicated details.
After that, if you want, expose a flat sheet at Zones 0 - X and develop all the film for the same time. Contact print, and then you can figure out whether you need to expose more/less and develop more/less.
You absolutely don't need a densitometer to make useful film tests. A densitometer is for plotting film/paper curves, and critical control. It's a refinement, not an addition, to one's method.
Using film since before it was hip.
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, Vol. 1 (8 Jan. 1819): 8-29. p. 11
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Don't forget to check the camera. The camera is your measuring instrument. You don't know what your measurements mean if you don't know your instrument. This is true for any measurement of any physical system. Even a Leica can be out of calibration. That is why their shutters have adjustment screws.