![]() Second wash and stabilizer bath are both pretty close to the standard times though. The KIS process manages to shave 5 minutes off of processing time with shortening those two steps along with shortening the first wash time significantly as well. Again you can cheat more with bleach & fixer than with developer. I'd say you can probably stray a good 10F either way and still get good negatives assuming you compensate for the change in temperature with either longer or shorter chemical times. I don' think lower temperatures will work at all. No crossover that I can see, no problems with processing at these times and temperatures, although I think that a longer end wash and a longer stabilizer bath wouldn't hurt. Kodak’s C-41 is the most common process for developing color negative films (Look for Process C-41 on the film box or cartridge.). IIRC, the temperature is 40C, which is I think around 105F. It cuts corners more with the bleach and fixer, but I think it shaves 20-30 seconds off of the developer time as well. The C-41 KIS process that I use for all of my C-41 produces comparable results compared with standard C-41. Personally, if I had to go out of spec for some reason, I'd study the effects first, either with a series of step wedges on the film I'm using, or an exposure series on a typical subject. ![]() ![]() They give C41 developer time = 3:15 standard, push1 = 3:45 and push2 = 4:15 minutes. Now the question is, "what IS push1 or push2"? One place I know of is Kodak's spec sheet for discontinued PJ800 film. Other films, you're probably on your own. I'm pretty sure that these films have been manufactured to behave well, so are probably fairly safe. ![]() There are some films where certain amounts of "pushing" (extra development) are condoned, the spec sheet may refer to "push 1" or "push 2" for an extra 1 or 2 stops of usability. With scanning and digital manipulation being common nowdays, the color problems are correctable if one knows how. If they don't, you could run into color cross problems, where light areas vs dark areas need opposite corrections ie, you couldn't fix it traditionally. What Peter has pointed out is more important if you do optical printing, because certain characteristics of the film and paper have to match up just so. That being said, of course you can modify things such that you no longer meet C-41 process specs. It specifies time/temp in all of the solutions, and additionally specifies measureable process results in the form of control strip aims and tolerances. Hi Keith, actually C-41 is not very bendable. > I know that the C-41 process is more bendable than most people are taught. In a color photogrpahy textbook by Henry Horenstein, and there was somethingĪbout the chart that made me think I needed to do further research beforeĪny light shed on these procedures woud be most appreciated! I have searched on the internet with no luck. With this method, have used it before, and I already have everything I need toĭo it, so please do not suggest that I go out and buy a Jobo or anything like I have been mostly OK, but have had a few sheets with marks. Sending a few sheets to a lab is fine, but at about $3 a sheet it adds up Need to get a batch ready for printing Wednesday and Thursday, and save some labįees. I am up for my own experiments, but right now I just Time-temperature adjustments apply just like with any other process. I know that the C-41 process is more bendable than most people are 3:15 at 100 degress F is a bit harsh for sheet film in hangers and I use a commercial CPAC developer that is at least that high a pH and has an even higher concentration of CD4 I believe, and it has the best test strip results of any I tried, so maybe processes have evolved toward the higher pH.I have run into some situations where I want to extend development times in theĬ-41 process. Stephan's best (C-29) is closer to this (OPs formula) in that it has fairly similar carbonate and sulfite and CD-4 levels but runs it at pH of 10.4 to get the contrast up to standard levels and balance. It seemed to help to also use the higher levels of carbonate and sulfite found in the phototechnologies formula. ![]() Interestingly, this formula has the same iodide, bromide and HAS concentrations as my best formula, but I had to increase the CD4 to 5.2g and run it at pH of 10.2. The results of this formula (substituting with KI and NaHCO3 equimolar amounts, and not using the PDTA) are:įrom tests by Stefan and myself, it seems we need a pH of 10.2 to get good red contrast levels. I just made some and ran the test strips and it did give similar results to one I ran earlier that had a similar pH and 4.75 g of CD-4. After trying a dozen or so formulas with test strips I was expecting this formula to have low activity, low contrast in red and blue due to the low pH of 10.05 or so. ![]()
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