Zone I Testing Again
Here I go again. I just finished testing Tri-X 4x5, 120 and 35mm and Fuji Neopan 100 Across for Zone I; Developed in XTOL 1:1
The test results are as follows:
35mm EI 200
120 EI 250
Fuji EI 100 (full speed - I'm surprised)
The 4x5 Tri-X were all too dense.
Has this ever happened to any of you? The tests were all done in the exact same lighting conditions, same meter. The EV readings were always the same. Same developer, at suggested time/temp - the whole nine yards. The lens shutter was tested for accuracy and was actually on the fast side. Obviously I did something wrong, but I'm stumped.
I'm going to test again, but I'm open to suggestions as to what might have gone wrong.
You should tell us your exact procedure.
Of course: I followed the instructions in Picker's Zone VI Workshop book. Black card in shade. A series of exposures for Zone I, rating the film at 320 640 250 160 80 and one unexposed negative. What is weird is that the other formats had successful results following the same procedure. I must have goofed somehow, i just wish I could figure out how.
Originally Posted by Renato Tonelli
No surprise to me. I tested three films last year and two of them resulted in faster film speeds than the manufacturer's. My lens was tested soon afterwards and was fine.
Ilford Panf EI 40
Fuji Acros EI 125
Tri-X EI 500
If you are confident that you did the procedure correctly, then you gotta take the results as they are.
How are you determining Zone I? Do you have a densitometer, (if so, are you developing in pyro, which will give false readings)? What values are you using for Zone I?
Are you using a printing method, e.g. "first recognizable step above maximum black"? Are you sure your meter reads well in the predominantly blue light of open shade?
Also, you may want to test for highlights (Zone VIII density) soon. If you are overdeveloping for "Normal," your film speed will be proportionately higher (1/3 to 1 stop depending).
There are many things you need to tell us/take into consideration before you can nail down "Zone I".
I make "Zone Rulers" at different EIs and contact print them to calibrate my film. This gives me the right development for the particular paper I like to use without any densitometer middle step. If you are interested in my method, contact me off-forum and I'll e-mail you the procedure.
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Yes, I'm using a densitometer to check the negatives. Development was/is as per Kodak's recommendations.
I tested the film again today, and the proper Zone one negative seems to be EI 800! In the mix I also had a portrait negative exposed at 320 and to the naked eye it looks like its overxposed by at least two f/stops.
If Peter (two posts, above) hadn't mentioned his test results, I would not believe them.
So, I've gained a lot of EI "speed" which I am very happy about. What am I losing?
Tomorrow I start testing for Zone VIII/Normal development.
Renato: Since you are using different cameras, you have to make sure shutter speeds on all lenses are accurate. Be that as it may, if the shutter used for the 4x5 gives you an effective EI of 500, then that's how you rate Tri-X with that lens/shutter. But when you use another lens/shutter, you may not get the same results, i.e. the effective EI may be different if the shutters are not matched.
Doremus: He is using Xtol, so pyro is not an issue.
Honey, I promise no more searching eBay for cameras.
Points well taken. As I slog through these endless tests, I have come across a shutter on my Fuji 300mm that is 1/3 slower. The focal plane shutter on my Rollei 3003 (35mm) is fast, the one on the Rollei SL66 is right on the money. I am making labels to note all these things and I must admit that it's more time consuming than I remember from when I last did it.
One question though: can testing for Zone VIII be accomplished with a densitometer, similar in procedure to testing for a Zone I? Not having to test print on paper would save several hours.
Yes you can find Zone VIII with the densitometer. Check Adam's book for the exact method. Should be in the negative.
From Adams' book;
Originally Posted by Nick Zentena
"As stated in the text, I have found that a Zone VIII density of about 1.25 to 1.35 is optimum with diffusion enlargers, or 1.15 to 1.25 with condenser enlargers. The corresponding densities for Zone V exposures are 0.65 to 0.75 with diffusion enlargers, or 0.60 to 0.70 for condenser enlargers. You may use these values for the development test, but you should judiciously adjust them if you find that they do not consistently produce the optimum negative scale in your own work."
From "Ansel Adams, The Negative, Book 2 of The New Ansel Adams Photography Series," Appendix 1 "Film Testing Procedures" Page 242.
Hope this helps,
Last edited by Zathras; 06-01-2007 at 04:06 PM. Click to view previous post history.