regennacht
Hello,
Unfortunately, development times are often only given for 35mm and roll films. I’d now like to develop 4x5" sheet film and was wondering whether I need to develop the film for a shorter time (due to the smaller surface area), and if so, by what ratio compared to the 35mm and roll film values.
Thanks,
Paul
Andreas_23
Hello Paul,
As far as I understand the chemical processes, there is only a correlation between the concentration of the chemicals (the intensity of the processes) and the development time, but no correlation between time and the amount of developer. As there is indeed less surface area to develop with a small film format, it might at most be the case that you can get by with less liquid, although you must of course ensure that there is enough for the entire negative to be submerged in the developer.
Franz (cfb_de) can certainly explain this to you in detail.
In any case, I develop all formats of the same film type (35mm, roll film, sheet film) with the same dilution and for the same duration.
Best regards,
Andreas
cfb_de
Hi,
When it comes to 35mm, roll and sheet films, there are differences in the emulsion used by some manufacturers. This results in different development times. On digitaltruth.com, you also have to factor in the faith, love and hope of mostly American amateurs.
However, as sheet films are developed to match their exposure anyway, there’s really no getting round having to experiment with single-frame tests. We all do the same with 35mm film, as the tabulated times have to be adjusted for each individual case to account for agitation rhythm, thermometer errors, dilution errors, spills and much more.
Regarding the possible reduction in time mentioned by Paul, I can say quite clearly that this is *not* related to the smaller film area. (If anything, it’s down to a different emulsion in sheet film.)
Negatives aren’t developed, and developer batches are traditionally oversized for negative development (to ensure the process remains controllable). This means that even with a minimum quantity, enough functional developer still ends up in the drain and only dies off in the second channel bend below the main channel.
Ergo: Using shorter times because of ‘film area’ is just as much nonsense as differences in cooking times between 250g and 500g of pasta. Chemistry explained in practical terms :-)
Best regards,
Franz (who just happens to be an expert :-)
regennacht
Thanks, so (whether it's a lot or a little) always cook the pasta al dente, right?! I'll do that.
hunnch
Thanks, so (whether it’s a lot or a little) always cook pasta al dente, right?! Will do.
Yes, of course, but with the right ingredients. Tap water plus NaCl (table salt). Goes perfectly with veal in a spicy pepper sauce.
Hermannn
PS: I’ll get cooking ;)
cfb_de
See, I know my chemistry, so I can cook too :-)
"Darling, how long does it need to fry for?" "Until it's done."
Best wishes,
Franz
Otto
Ilford’s data sheets do not distinguish between different film formats. With Foma, however, I have found significant differences between 35mm film and sheet film.
As Franz already mentioned, testing is particularly important with sheet films. The development method – e.g. tank or tray – and the type of agitation can lead to variations in development time. With tanks, there are also different designs, some with and some without a tilting mechanism.
Best regards,
Otto!
PeterVolkmar
In short: using shorter times for ‘film runs’ is just as much a load of rubbish as the difference in cooking times between 250g and 500g of pasta. Chemistry explained in practical terms :-)
Best regards,
Franz (who just happens to be an expert :-)
I’m afraid I have to disagree with you there, Franz. When I first started testing my sheet films, I exposed one sheet with the Sensitizer and developed it using the developer quantity for one film (=4 sheets). Once I’d got my times, I put in 4 sheets and they were underdeveloped. Next development: 3 sheets with normal exposure and one sheet exposed with the Sensitizer – a spot-on -1.5N development.
But you’ll have to explain that to me in detail ;-)
Regards, Peter
cfb_de
Hi Peter,
Which developer was that? Are you sure it was strong enough? In my Jobo 3006, for example, I can’t even get started with Rodinal 1+50 if there are more than three films in there.
But that has little to do with ‘adjusting development times’; rather – to use the pasta analogy again – it’s a problem of this sort: too much pasta and not enough water in the pot :-)
Best regards,
Franz
PeterVolkmar
Hi Franz,
That was 100 Foma in LQN. And the amount was fine for four sheets, let alone just one ;-)
I reckon that although the developer is generously proportioned, there’s quite a difference between having one sheet in there and four. If you’re developing in the stock solution of any developer, you usually have to allow for more and more time.
Regards, Peter
