PaulJohn Posted March 10, 2018 Share #1 Posted March 10, 2018 Advertisement (gone after registration) Massive dev chart: Delta 100 @100 in ID-11 1+1 = 11 mins Delta 400 @400 in ID-11 1+1 = 14 mins Looks right as I am used to seeing longer dev times on faster films But Delta 100 @100 in Rodinal 1+25 = 9 mins Delta 400 @400 in Rodinal 1+25 = 9 mins So Delta 400 takes longer to dev than Delta 100 in ID-11 but takes the same time as Delta 100 in Rodinal. Why might that be? Quote Link to post Share on other sites More sharing options...
Advertisement Posted March 10, 2018 Posted March 10, 2018 Hi PaulJohn, Take a look here Dev times look wrong. I'm sure you'll find what you were looking for!
Doug A Posted March 10, 2018 Share #2 Posted March 10, 2018 Massive Dev Chart is crowd sourced. The data should be thought of as nothing but a starting point for determining what works best for you. 3 Quote Link to post Share on other sites More sharing options...
adan Posted March 11, 2018 Share #3 Posted March 11, 2018 Doug A is quite correct - the MDC is suggestions from a great many different photographers, and therefore their tastes in what makes a "good negative" (more density, more contrast, less density, less contrast) may result in times that don't necessarily track with one another. However - it is not actually accurate to assume a high-ISO film requires more development time than a lower-ISO film. Delta 400 is not simply Delta 100 developed for a longer time - it has its own characteristics. Photo chemistry is not that straightforward and simplistic. Kodak's own times for their films in TMax developer (20°C) are TMX 100 - 8 minutes TMY 400 - 7 minutes TX400 (Tri-X) - 6 minutes Fuji's times for ACROS 100 and their now-defunct 1600-ISO film (D-76 stock @ 20°C) Neopan ACROS 100 @ ISO 100 - 7.25 minutes Neopan 1600 @ ISO 1600 - 7.5 minutes The development of film is a complex dance involving 4-8 chemicals in the developer (or less, if you count "caffeinol" ), and various proportions of silver and gelatin compounds in any given film, not just "developer + silver halide = silver + hydrogen halide (waste)" in a 1-to-1 reaction. The various developer "parts" can restrain or accelerate the reaction; the by-products of the developing process (which can be affected by the film itself) can restrain or accelerate the process (and react with each other as well as the film to produce even more by-products), the thickness of the gelatin can extend the developing time as the liquid developer percolates down to the deepest silver crystals, etc. Part of the "speed" of the film, in both ISO and developing time required, may be built right into the film itself, thus allowing a higher-ISO film to develop in less time than a lower ISO film, other things being equal. 7 Quote Link to post Share on other sites More sharing options...
tobey bilek Posted May 15, 2018 Share #4 Posted May 15, 2018 All I can say is I never had luck with MDC. I find Kodak and Ilford times perfect for their respective films their own developers printed with diffusion enlarger, condenser enlarger subtract 10%. Changing paper grades is not the same. Bergger 400 is also spot on. MDC is at best a poor starting point. Some water PH varies, some thermometers are off, some agitation schemes are different. Times need to be developed using laboratory controls, i.e. everything perfect. Make your own chart. Six exposures is 12" of film , cut off a run a test. 1 Quote Link to post Share on other sites More sharing options...
semi-ambivalent Posted May 20, 2018 Share #5 Posted May 20, 2018 filmdev.org But Doug A is still correct. Quote Link to post Share on other sites More sharing options...
Michael Hiles Posted May 20, 2018 Share #6 Posted May 20, 2018 Note all the above - read, mark, learn and inwardly digest. Then do you own well organized tests. That is the only way to know for sure. 1 Quote Link to post Share on other sites More sharing options...
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