View Full Version : I'm a film testing moron- wadda ya think?

18-May-2007, 21:44
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?


Mike Davis
18-May-2007, 21:54

Did you redetermine your Person EI after switching to th View Camera. Personally I use FP4 at either 100 or box speed and general produce negatives suitable for ~grade 3. But this is with my lenses, dip and dunk method, etc.

I don't think it matters how you get to the point where you have the negatives you want, but I'm not sure how someone else can do all of your testing without your camera and your development (and printing for that matter). But maybe I'm missing something.

The fact that the still lifes were overexposed makes me think that you are rating the film too slow. But I have hear of others rating FP4 at 64 or so as well.


Brian Ellis
18-May-2007, 22:12
I used to do my own testing but after going through a box and a half of APX 100 film trying to get consistent results and being unable to, I started using The View Camera Store, which is what I'd recommend you do. It costs about $35 and you'll get more and better infromation that way than you'll ever get on your own, plus you'll save a lot of time and frustration.

But just in case you choose to continue on your own - did you check to make sure the dark cloth (or the parts of it you were photographing) was evenly lit from center to edge and corner to corner? You can check this with a spot meter. A dark cloth doesn't strike me as something that would make an ideal target because of little folds and wrinkles that usually find their way into the cloth. The target is supposed to be smooth, without any indentations or major variations in texture, such as a piece of card board or a gray card. Obviously if your target isn't evenly lit the film will have different densities no matter how good your development technique is.

18-May-2007, 22:23
I use a kind of sloppy zone system test for my cameras. I guess at best it would be a little bit of Picker, and a little of BTZS. Set up a large card, and bracket around zone I to get the film speed. I read the densities on the processed film with a handheld digital light meter on my lightbox to find 0.1 over film base+fog. Then I do a zone VII and VIII exposure, print them at a previously determined maximum black time at my enlarger and visually compare the two. I adjust the film developing time to get zones VII and VIII in the proper places.

That's the precise and nerdy way to do it, yet when it seems every other month papers are discontinued, film formulas are changed, chemistries disappear ........ it hardly seems worth the effort these days. As soon as everything is dialed in, "poof!" something on the supply side changes and the whole process has to be redone. And what about old negatives I want to reprint? Some of those old papers I calibrated to are gone forever (Agfa MCC).

I mostly judge everything all by eye now. Good enough shadow detail, develop so there aren't any really blown highlights. Sloppier still, but in a way it's bit liberating. :)

19-May-2007, 04:02
Ya I wonder about the dark cloth to. I also wonder if you focussed at infinity during the test? Or if you took bellows factor into account if you didn't.

I use a wall that's zone VI. It's fairly evenly lit from large windows most days. Plus I can always wait for an overcast day.

Over developed should have been higher then expected contrast.

I tend to test with smaller formats then do a final sanity check with the bigger camera and lenses.

19-May-2007, 11:00
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. Thanks for your input.

Henry Ambrose
19-May-2007, 14:41
I think you're using too many materials, ratings and too short a development time. These things make your system too responsive. (at least for now since you're just starting)

The difference between 64 and 80 is only 1/3 stop. For practical purposes under reasonable conditions you'd have a decent negative using either speed. Which is another part of the problem. You might think that number should make a big difference but it does not.

I suggest you shoot a typical scene illuminated by open sky under constant conditions with three sheets of film exposed all the same. Set up on the shady side of a building out of direct sun but lit my open sky and shoot your film quickly but carefully all at the same exposure. The scene could include an open book, a mid colored bath towel and a black fuzzy stuffed animal. (just examples but the scene should include a nice range of reflectances). Don't make it macro, stay away from extension factors. Set up the camera several yards away. Stay away from slow and high speeds. Try for 1/30- 1/125th or so. Maybe its gonna be around f11 at 1/30 under the set up I defined.

Rate your FP4 at 64 or 80 (either one, just pick one and stick with it for now). Look up a dilution of your developer (stick with HC110 since you have that now and don't change for several months) that calls for around 10 minutes development. Develop your three sheets one each 8, 10, 12 minutes. (20% change either way) Longer times help you be more precise with your changes and make your timing mistakes proportionately smaller.

Print these negatives per your usual practice. One of them will be clearly best. Use that time as your normal if you can make a nice print with it. Then go make some pictures. You can fine tune from there but I think you're gonna be real close.

Glenn Thoreson
19-May-2007, 18:14
I don't understand all the testing. Everyone has their own way to do it, each with different results. I just shoot FP-4 at 100, using some very simplified zone system methods. and/or a gray card, and develop in PMK Pyro. It works. All the tones are there and they print easily. With other materials, I may use D-76 at 1:1 or Diafine, but I have pretty good results without a lot of fuss. Even when using box cameras, which give little or no control. I know some would consider me a little off my rocker, but to me, simple is better.

Bruce Barlow
20-May-2007, 06:20
Howz come you didn't return to the source and ask? I oughtta have hurt feelings...

Is there any chance that the tests are right, but the field practice has a flaw? You're way too close with your test results to be getting the results you appear to get in the field. A WAY overexposed will also be WAY overdeveloped, so I suspect a flaw in, maybe, metering technique. Spotmeter? Aim it at the brightest thing in the picture (white, fluffy clouds, for example). Take the exposure the meter tells you and open up three stops (meter's telling you the clouds are Zone VI gray, open up three stops to get them Zone VIII white). Set the opened-up exposure and make picture. Accept gratefully what you get in the shadows, cuz they're unlikely to be below Zone III anyway, and that's lovely. Print higher contrast if you need to. If you get the exposure right, I'll bet you the development time is very close to perfect. By the way, my own testing of FP4 gave me an ISO of 80 and an HC-110 development time of 5 1/2 minutes (but see caveat below).

Another possibility is that your proofing time is too short, and thus proofs too light. Are you SURE you're calibrated for minimum exposure for maximum black through clear (film base+fog) film?

I don't understand the uneven test negative stuff at all, since you describe following the instructions quite well. As far as development time, I don't know what Winnepeg water is like, but my development times changed when suburban Chicago changed from hard well water to much softer Lake Michigan water. So as a caveat, water hardness or softness matters for development time.

So, to also agree with others here, the time for testing is over. recheck your metering and exposure setting technique, and then make real pictures. Minor speed and development time adjustments can be made from examining your Proper Proofs.

Good luck. If you're still having trouble, contact me at BBarlow690@aol.com and we'll figure it out.

All best,

22-May-2007, 17:50
Bruce- thanks, as well as everybody else. I don't think the system is flawed (so please don't take offense ;) ), just my method of puting it into practice. I know that metering can be tricky, and it may confound me from time to time, but I feel confident for these "simple" exercises I've done. I'm also confident in my proofing time. I found similar difficulties when I was calibrating my enlarging meter- also comparing black and white tiles. I stare too long at them, then can't tell what I'm seeing!

These are all good suggestions- I will see how things go this time around. I'll try 6 1/2 minutes to start. Iwill use +25% for N+1 and +33% for N+2, and the opposite for Minus- this seems to be the general consensus.