T Max 100 vs T Max 400 development times
Does anyone out there find that the 100 requires slightly more (+10% or so) development time than for the 400? This perplexes me, as slower film usually requires less development.
I have found this, repeatedly, to be the case. I am using fresh film, same developer (both clips developed in same tank), controlled lighting. The determination factors for me here are: identical contrast yielding the same shadow detail. - David Lyga
Good Morning, David,
Optimal "normal" times are slightly different. I use 10 minutes for T-100 and 9 minutes for T-400, both in T-Max developer diluted 1:7 directly from concentrate. With times so close, however, I wouldn't hesitate to process both films together in the same tank for, say, 9.5 minutes, assuming a non-critical situation. With roll film or 35mm, the reel with T-400 film can be put on top in the tank and pulled a minute ahead of any T-100 and dropped in the film washer while the T-100 continues development for another minute. Most of the time, I will slightly adjust the time for either film depending on the subject contrast.
But the fact is that you just confirmed my suspicions and for that I thank you. 'Development tables' are one of the most frustrating factors in analog photography. They ALL state that 100 should be processed LESS than 400. That seems to be the 'necessary' thing to say even if, in the real world, that is not the case.
Usually the slower the film, the less development needed to attain adequate contrast. There was another exception that I remember: Panatomic X which required considerably more development time than Ilford's Pan F does. There simply is no set formula here and each film type must be determined privately because development tables apparently are not all that accurate (or even in agreement with each other's).
Of course, it must be said, with emphasis, that exposure plays a part in the final contrast as well, and this exposure must be accurate in order to be able to compare film development times with the prospect of attaining consistent results. My exposures were exactly two stops apart and conform to the box speeds (which are accurate for these two films.)
Again, Konical, the difference is sufficiently trivial to 'make up' for the difference with enlarger filtration. But that difference goes the WAY that I thought I was experiencing and that is significant to me. - David Lyga
Last edited by David Lyga; 11-08-2012 at 08:47 AM. Click to view previous post history.
You can certainly throw out the impersonal development tables if you use a sensitometer to expose test strips and graph the results... It is very nice to go to the notebooks and see a graph that "fits the ASA triangle" and know that, for that film 11 minutes is "normal".... for me. And once you have a family of curves, you can go from there. Even if you didn't do Zone System notes, you can remember the roll was shot on a foggy day so check the graphs to find which one would "expand" one stop more as if N+1.
Originally Posted by David Lyga
Love the smell of Panatomic-X, couple days ago I took in a deep savoring sniff from the paper backing...
Originally Posted by David Lyga
Also, it only needs 4 minutes in the fix.
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Shoot fuji, the acros 100 in 35 AND 120, the neopan 400 and the 1600 all use the same exact time and can be developed in the same tank.
Strange that tmax 100 need more time as it can be pushed to 200 without changing anything (or so Kodak claims anyway)
A good opportunity to consolidate to using one film. Tmax400 is pretty handy. For big enlargement smoothness and less magnification, I've preferred going up in film size to a MF/LF rather than massively enlarging 35mm tmx even though it has fine grain.
There really isn't any strong connection between the development times of two different films, unless they have been designed to be so connected by their manufacturer.
There is a lot of difference between the two films, so it doesn't surprise me that the development times do not follow the pattern observed in other films.
And as for Kodak's recommendation for dealing with one stop of under-exposure for either T-Max 100 or T-Max 400 (no increase of development time) that is merely a reflection of the fact that Kodak has determined that the inherent latitude of the films means that the loss of shadow contrast resulting from one stop under-exposure is less of a problem then the loss of highlight detail and contrast that results from increasing the development time. It goes without saying that increasing the development time doesn't create shadow detail that isn't there.
“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”
Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2
MattKing, I was careful to not allow highlight blocking through over development but your point is well made about Kodak's reasoning. However, I would refute Kodak in that a one stop underexposure does (slightly) affect contrast and I would therefore increase development time for the underexposed film by maybe 5%. Rather trivial adjustment but theoretically sound. - David Lyga
Last edited by David Lyga; 11-09-2012 at 08:10 AM. Click to view previous post history.
Just a thought David, while I do agree that the total density will be lower with less exposure, that doesn't necessarily mean a change to the film curve is needed.
I think what Kodak is essentially saying is that for typical use either EI 400 or 800 there will normally be plenty of info to make virtually identical prints of typical scenes.
Yes, surely for high contrast scenes or tightly spot metered work, there very well could be impacts on the print but for most people it won't normally matter.
Mark Barendt, Ignacio, CO
"The mind that opens to a new idea never returns to its original size." Albert Einstein