Kodak 400TX development time
Posted: Thu Dec 15, 2011 4:58 pm
I am in the process of establishing the proper development time for 400TX film with my camera and darkroom equipment. However, the time resulting from tests so far seems unworkably short.
Details - I first established my personal ISO speed for this film, 500 in my my case. Then I exposed a roll (120 size, 12 exposures) one frame each at Zones I through VIII, two more at zone V, and two unexposed frames, and developed it for five minutes and 37 seconds in HC110 B. Next, with an unexposed negative in the enlarger I did the two second interval strip test to find the minimum exposure needed to produce maximum black; this was 18 seconds at f22.
Then, with the Zone VIII negative in the enlarger I gave a piece of paper the same exposure , 18 seconds at f22, with half of the paper covered to prevent any exposure. The expectation is that, if the negative was developed for the proper time, the exposed half of the paper should exhibit a very slight tonality, or departure from totally white, compared with the covered half. This procedure is described in the book entitled The Zone VI Workshop by Fred Picker.
The paper printed completely white with no discernible difference from the covered half, indicating that the negative was developed too long. The next logical step would be to process another roll with a shorter development time, say 25 percent less, and try again, but but here it gets puzzling. The Kodak data sheet for 400 TX recommends 3/3/4 minutes but a footnote at the bottom cautions that development times shorter than five minutes may yield unsatisfactory results. At 5 1/2 minutes I am already nearly at that.
Might a more dilute solution than B (1/2 ounce in 16 ounces of solution) do the trick?
I note that the Massive Development Chart recommends 7 1/2 minutes for 400TX at 68F. That's what I started with before going to 5 1/2 minutes.
I am using Ilford RC paper.
Thanks for any help,
John Billings
Details - I first established my personal ISO speed for this film, 500 in my my case. Then I exposed a roll (120 size, 12 exposures) one frame each at Zones I through VIII, two more at zone V, and two unexposed frames, and developed it for five minutes and 37 seconds in HC110 B. Next, with an unexposed negative in the enlarger I did the two second interval strip test to find the minimum exposure needed to produce maximum black; this was 18 seconds at f22.
Then, with the Zone VIII negative in the enlarger I gave a piece of paper the same exposure , 18 seconds at f22, with half of the paper covered to prevent any exposure. The expectation is that, if the negative was developed for the proper time, the exposed half of the paper should exhibit a very slight tonality, or departure from totally white, compared with the covered half. This procedure is described in the book entitled The Zone VI Workshop by Fred Picker.
The paper printed completely white with no discernible difference from the covered half, indicating that the negative was developed too long. The next logical step would be to process another roll with a shorter development time, say 25 percent less, and try again, but but here it gets puzzling. The Kodak data sheet for 400 TX recommends 3/3/4 minutes but a footnote at the bottom cautions that development times shorter than five minutes may yield unsatisfactory results. At 5 1/2 minutes I am already nearly at that.
Might a more dilute solution than B (1/2 ounce in 16 ounces of solution) do the trick?
I note that the Massive Development Chart recommends 7 1/2 minutes for 400TX at 68F. That's what I started with before going to 5 1/2 minutes.
I am using Ilford RC paper.
Thanks for any help,
John Billings