development of large format negatives : LUSENET : Large format photography : One Thread

When developing 4x5 or 6x9 film, do you need to change dilution of the developer or increase the time from 35 mm film?

-- kathleen chambers (, October 16, 2001


Neither. You need to ensure you have a sufficient quantity of developer for the amount of film (sq in) that you have. A roll of 35mm film has about 80 sq inches. An 8x10 film has about 80 sq inches. So you would need the same quantity of developer for one 8x10 sheet of film as for a whole roll of 35mm film. Cheers, DJ.

-- N Dhananjay (, October 16, 2001.

Kathleen: Oftentimes the development times are different between "roll film" (120 and 35mm) and "sheet film" even though they are the "same film." So don't assume that the tried and true 35 mm times you use are necessarily the best place to start if you happen to buy that same favorite film in sheet film sizes. If you want to start with the manufacturer's times, make sure you've got the instruction sheet for what you are actually using. If you tell this forum what film you're using and what developer, people will pipe up with some very good starting times.

-- Kevin Crisp (, October 16, 2001.

I'm curious - is this really the case? I have always asumed that these differences reflect the fact that we agitate roll film and sheet film in different ways. I remember Kodak's recommendations were based upon intermittent agitation for roll film but tray developing (i.e., constant agitation by rocking the tray) for sheet film. In other words, differences in time are merely to offset the differences in agitation. Or is there more here than meets the eye? I know some emulsions are different (e.g., TriX in sheet film is different from that in 35mm) but leaving things like that aside, identical processing of similar emulsion should require similar times.... Cheers, DJ.

-- N Dhananjay (, October 16, 2001.

Well, here:

Ilford lumps them all together, or so it seems.

-- Sean yates (, October 16, 2001.

For example, tray development may have different agitation than tank development.

Sometimes, it depends on fluid dynamics, which is more physics than chemistry. For example, TMax 100 in 4x5 is exactly the same emulsion as TMax 100 in 2.25 roll film, yet it requires a different chemistry for development. Since 4x5 sheet film has more surface area per image than roll film (e.g. 2.25x2.25), the TMax original developer accumulates more local negative by products which can stain the film. So, TMax developer RS was developed to control the accumulation of these by products.

-- neil poulsen (, October 16, 2001.

I process 35, 120 and 4x5 all in a JOBO and use the same times for all three and have never seen any difference in the negatives. I think I read somewhere that T-grain films have a different thickness of emulsion between roll film and sheets, although if true, I have not seen a difference with these films after processing.

-- James Chinn (, October 17, 2001.

For some reason manufacturers always used to think that sheet film should be developed to a slightly higher 'gamma' than miniature film, and their recommended times would give something like a Gbar of 0.6 for 35mm film and 0.7 for sheet film. If you take this to its logical conclusion, you'd only use lith film in a 20x24 camera!
Anyway, there's really no need to make any distinction between film formats when it comes to development, except that film with the same name sometimes has very different emulsions in its 35mm and sheet film guises. Tri-X is one that springs to mind.

-- Pete Andrews (, October 17, 2001.

I think manufacturers recommending high CI for sheet film (even using identical processing methods) is a relic of bygone eras when sheet film was typically contact printed and roll film was enlarged (if you're contact printing, you typically need to develop the film slightly longer than if you were enlarging). I don't think that is relevant to 4x5 when the end use is for enlarging. Cheers, DJ.

-- N Dhananjay (, October 17, 2001.

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