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  #11  
Old 27th July 2020, 02:36 PM
JOReynolds JOReynolds is offline
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I agree with basing your research on XTOL. I did a lot of research using it with the SmartLab project, which was one-shot 1+1 in a rotary processor, and the results were always excellent. Most of the later tests were at 30°C because the client wanted it to work in a tropical environment and yes, we tested it with several emulsions that were thought to be physically too soft at elevated temperature. Some emulsions began to frill in D76 at that temperature.
Perhaps using the same equipment and procedures that you propose, I clearly recollect that the velocity of image formation, once incubation begins, is independent of developer formulation.
By the way, I use Rodinal 1+50 for Delta 100 and 400 and I stick to the Ilford time/temperature table. And yes, I used a densitometer and step-wedge, although once I found that Ilford's recommendations were sound, they haven't been used for years.
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Old 28th July 2020, 09:07 PM
maxwellmakosk maxwellmakosk is offline
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@Mike O'Pray Its true I am trying to compensate for developer temperature. The primary motivation for writing this script is to make the process faster ( I develop up to 6 different films at a time it can be a pita to plugin x and y for each tank.)

@Stocky / Mike / JO: Yeah honestly I have no clue what to expect. I have used a formula based off ilfords chart as well and found the negs far too dense at some of the higher temperatures. I also went and found the thread I was referring to here. On the first page of the thread someone mentions a quote from "Developing" apparently confirming different developer formulations have different temperature coefficients. Same with specific films for a given developer. I hope to find that the temp coefficients for different films in xtol are too small to matter but we will have to wait and see.

Of course Im sure the ilford chart is fine and if I did some sort of blind neg test I may not be able to tell the difference but my goal overall is to get as accurate temperature conversion as possible for as many films as possible (with xtol) and be able to calculate them as fast as possible. I may create this and realise its no better than one formula to rule them all but I hope to be surprised! Like previously mentioned I want to port this over to python if it is successful and support more user oriented features like hosting it on a website or something who knows. I'm sure you guys can suggest what to do if I ever get to that point.

Last edited by maxwellmakosk; 28th July 2020 at 09:22 PM. Reason: didn't see second page
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