C-41 stand developing

Discussion in 'Film and Processing' started by earlz, Mar 31, 2018.

  1. Is anyone else out there using C-41 stand development regularly? I use it for nearly all C-41 film I develop because it's easier and more consistent. I've gotten more processing mistakes with the normal and fast development method than stand development. My process is: use room temp (64F) developer, develop for 45 minutes total, agitate first minute, and then once at the 20 minute mark, and use normal hot blix, stabilizer, etc. The results are very easy to use for scanning, but I've never tried color prints from the negatives before. I've been told that this will screw up the color balance and make prints difficult.

    Anyone else use it and have a consistent process established?
     
  2. The reason it's called C-41 is because it was designed to be used at 41 degrees Celsius.

    How does 'stand' development improve things? And I'm not sure dunking film straight from 'cold' developer to hot blix is a good idea.
     
  3. It doesn't improve much, it's just a lot easier to be consistent with. And I warm up the tank and film using a rinse between dev and blix.
     
  4. As far as developing is concerned, it's a bad idea. The reason for development, the way devised, is to ensure all the colours et developed at the same rate to insure fidelity. Slowing down the process will allow the colours to develop differently.

    Stand developing could be obtained with a re-engineering of the film formula and the developer formula. I wouldn't waste your time waiting in line for that one... :)
     
  5. earlz, interesting, I have not heard of this. Can you post any images with stand development and C-41?
     
  6. Hi, I usually avoid making opinions on methods that I have not actually tried, but...

    Are you actually saying that it [stand developing] is more consistent because you don't make mistakes, whereas you DO make mistakes when using the standard procedure?

    The obvious counter argument to this is to, when using the standard method, is to stop making mistakes, right? Then you should have consistent processing with the added benefit of saving ~40 minutes of your time during each processing run.

    As a note, I've spent a large part of my life being involved with professional processing and printing of color negative films, with particular involvement in what they call (statistical) process control. Part of this is to test consistency of processing by periodically running special test strips with rigidly-controlled exposures; these are then "read" with an instrument (densitometer) to evaluate the degree of development. Now, having seen that there is little room for improvement of consistency (based on densitometer readings to 0.01 density units) I can't imagine that "stand development" could be more consistent.

    Again, I've never tried stand development, but in principle it seems that two films, with different exposures, would vary in the extent of development. The bottom (color) layer of the film is largely affected by the extent of development in the upper layers, and it seems that not agitating the developer (to sweep away byproducts and bring fresh developer to the surface of the film) would aggravate the differencs. I DO know that when agitation is reduced in a machine process, a reduced amount of development, both overall density and contrast, can be seen in the bottom layer of the film. So I presume that NO agitation (aka stand development) carries this effect even further.

    The contrast issue is not correctable in "normal" optical printing (scanned images are a completely different situation) giving a result we call a "color cross." If you have a color cross in photos of people, you would find, for example, that lighter flesh tones would have a slightly different color than the darker tones. If you try to correct one of these, the other goes in the opposite direction - they are essentially not correctable with standard methods. This can be a fairly subtle effect - most people could probably not explain what looks wrong with such an image, but if they have two images side by side, they can often recognize that something is not quite right with the color-crossed image.

    As a note, from actual experience, with properly processed and printed Portra 160 film, a "normal" vs 3 or 4 stops overexposed negative will be virtually identical, colorwise. I can't imagine this would happen with stand processing.

    Anyway, bottom line to me is that it's kind of nutty to vary from the spec C-41 process conditions if one's goal is to get high quality color prints. In my experience, when people recommend way out-of-spec methods, they generally have not made stringent comparisons. OR, they are using scans, then push and pull until they get the image where they want it.
     
  7. I don't know how Kodak named this, but I'm skeptical. When this process was first introduced, the process temperature spec was 37.8 degrees C.

    Also, there is another process, generally unknown to photographers, called C-42, which operates under the same time and temperature specs. Same temp, but different process number.
     
  8. The film is designed to be processed at 100F for 3' 15", for optimum results and nowhere else. Different times and temperatures can degrade images. I have tried developing at room temperatures for extended times and got "crossover", color shifts with density changes. This is quite noticeable when laying prints side-by-side with prints from negs done right. But you are the judge of whether it is acceptable to you. The crossover may be correctable with software after scanning if you know what you are doing.

    I develop the normal way and get good, consistent results. If you aren't, you should review your process.
     
  9. As a note, this is the same thing that I referred to as "color cross," which goes by a handful of similar names in the photography lingo.

    In any case, these crosses are a result of improper contrast matches between the different color layers of the film. And like Rob says, it's all designed to work just right at a specific time/temperature and agitation; anything else is just a crap shoot.
     
  10. C-41 took over from C-22, which was processed at around 22 degrees C. Coincidence?

    There was no C-23, 24, 25 or other designation introduced between the two.

    OK, so the recommended temperature for C-41 isn't exactly 41 degrees. I suspect the experimental formulation might have been aiming for this temperature, but was lowered for practical purposes.

    Anyway, in the distant past I've used 'room-temperature' colour processes that were no more consistent than the care taken to ensure accurate timing and temperature control. It just took longer to see any mistakes!

    In general the best colour quality achievable from RT processes fell below what C-41 is capable of.
     
  11. Wow, a lot to catch up on. So, I don't do optical prints, but the only film I have trouble color correcting (I do DSLR scanning, and correct the color in Photoshop using curves) is when it's vastly under exposed, vastly over exposed, or when using ECN-2 film (Cinestill). I've not noticed any cross-over color, though I would assume the exact development and resulting curves is probably a bit different. This is easy to correct while scanning though. Only now (thanks to a sous vide machine) do I have a good setup for fairly precise temperature control. Beforehand with normal C-41 processing, I had way too many negatives that did have color casts, under development, washed out colors, and artifacts (stripes etc, though this may have been from cinestill processing). Stand development, I can load the tank, pour in the chemicals, and then go watch TV for 20 minutes. My process is not quite just stand. C-41 dev temp is at ~63F/17C, agitate for first minute, and agitate once after 20 minutes. Develop for a total of 45 minutes (or up to 47 when the chemicals start to get weak). I blix etc as normal.

    I'm about to be traveling, but I plan on whipping up a new batch of C-41 when I get back, and doing several test strips with a color chart to actually measure what the effects are objectively. I'll make sure to report about it here. I'm sure it probably will vary some depending on film stock too. I also have another thing I'll do a write up on called "x-pro reversal". Basically processing E-6 film in C-41 chemicals and producing positives. I love experimenting with new processes in development.

    I have some images attached as examples for stand development. Note I'm still learning how to best do color correction with curves. I can provide raw negative scans if anyone wants to further analyze them

    Ektar 100:
    _MG_3868.jpg

    Portra 160:
    _MG_2454.jpg

    Superia 400:
    _MG_2285.jpg

    Portra (I think) 400 pushed to 1600, half-frame:

    raw0035.jpg
     
  12. FWIW, C-22 was processed at 28 degrees, C-41 at 38 degrees.

    I'd guess that the numbers are more likely to have had something to do with in-lab cataloguing of processes...
     
  13. I've never done C-41 myself, but do E6 at 40.5º.

    There again, I'll confess ignorance but I'd always thought that the temperatures for the two processes were close.

    To be fair, by the time I get to the Blix stage I'm usually at around 37º, but since color developer and blix are done to completion I just extend the time a bit rather than worry about them being lower than spec temperature. I AM careful about the time and temperature on the first developer, though.
     
  14. The C41 kit I use says 102º F which is about 39° C for hand tank or dip and dunk.

    For rotary tubes, it gives multiple temps and times. For example it says for 75° F for 17.5 minutes, 10.25 minutes for 85° F, and 3.5 minutes for 104 °F

    So there seems to be some flexibility on temps and times. I've never used a rotary processor but my understanding is that there's a constant agitation.

    earlz: ultimately if the workflow suits you and you get the desired results, there is nothing wrong with what you're doing. So far, I've had good results with standard processing and would just soon have it take less time than more. ;)
     
  15. "To be fair, by the time I get to the Blix stage I'm usually at around 37º, but since color developer and blix are done to completion I just extend the time a bit rather than worry about them being lower than spec temperature."

    Is that true? I thought overdoing color development on E-6 would result in cloudy and dark slides with too dark of shadows, even if first development was correct. I think color development is less essential for determining exposure, but I assumed it was not a "to completion" process
     
  16. No, I think this "flexibility" is only from the aftermarket manufacturers, isn't it? If you want stringent control of the process, and want to do high quality pro work, you should probably stick with the Kodak recs (see their publication Z131 part 3 for rotary processor specs).
     
  17. Hi, I'm not trying to be mean, but your success with color is largely due to what might be called, uh, very "relaxed" standards for color.

    If you really want to see how your results really compare, I'd suggest to shoot a couple of duplicate rolls, sending one to a reputable lab; process the other yourself (use a "proper" sort of lights for the shots, either flash or daylight). I come mainly from the world of prints, so this would be my preferred comparison. You CAN do it on a monitor, but it's really easy for your judgment to get corrupted without a known-good reference.

    Regarding crossover, look at your third sample shot - the room with the travel chest. The left-hand wall, as it goes from light to dark, changes to a purplish color. Now this could be due to the lighting, but otherwise...

    Something like a Macbeth ColorChecker is a good reference, light it with flash for best results. But how will you "objectively" measure the color? (If you are strictly scanning, you're gonna have to do some image processing.) Ultimately you could have prints made, then compare against the original color chart, but it's gotta be under the proper lighting conditions. I'm sure it'll be a good learning experience - things are not as simple as they might look initially.

    Ps, the grey scale on the Macbeth chart is useful for seeing a color cross in the neutrals, but a continuous grey gradient is better. But color crosses also occur in other colors; you can have a perfect neutral scale, but still have color crosses in skin tones. (I've spent a lot of time doing very serious color testing.)
     
  18. I think it's safe to say that earlz isn't that interested in stringent control of the process. ;-)

    Also in the kit instructions is a large section on solution capacities, - how many rolls can one process and get good results. In one paragraph they list 4 things that can affect the capacity, the last one being: "how far can the results deviate from ideal before the user deems them unacceptable".

    They state that 8 rolls of 36 exposure 35 mm film is the recommended capacity for this kit, but there's no doubt that the 8th roll isn't going to be as "ideal" as the 1st. Especially if it's been a few months since the chemicals were mixed, there was some contamination, etc. Even in a professional setting, I doubt that every roll is processed in a freshly mixed batch of chemicals. So yes, there is some flexibility. There is some variance from ideal that is deemed acceptable. And if you have a hybrid workflow, that variance from ideal can be larger since digital scans can be manipulated to a high degree.

    I don't doubt that if you process at lower temperatures for longer times that the results will be somewhat different. But if the differences can be easily eliminated in post, or are so small that they can't be noticed unless compared side by side on optical prints (which aren't they intended end product), does it matter?
     
  19. Just another thought: If I owned or worked at a lab where professional photographers relied on me to give them consistent results, I'd be highly inclined to make sure I followed an exact process, have my equipment regularly calibrated, etc.

    Personally, with color film I'm pretty by the book. It's part of the enjoyment for me. I made a DIY chemical warmer using an old roaster oven, an aquarium pump, and a Raspberry Pi. I spent a lot of time tweaking code to make it better at maintaining the right temp. All overkill, but I enjoyed it. My most important roll of film in a batch is the one I processes 2nd to make sure I didn't screw up the chemicals and to make sure they are fresh.

    With B&W, it's just the opposite. I'm much more inclined to experiment with Caffenol and other alternative processes. So I understand where the OP is coming from.
     
  20. Again, I can't comment DIRECTLY since my at-home color is limited to E-6, but the kit I use does answer the "how far can I go" question and suggests compensation times as the chemistry is used.

    For home E-6, I wait until I have enough to basically use the chemistry to its recommended capacity and will generally keep at it for a solid day or day and a half until I've done everything. Counting prep time and everything else, that's roughly 1 hour per batch(actual time in chemistry runs about 45 minutes). I have spread it out over two weekends before, which means I stored used chemistry for a week, but I'm afraid to push it any more than that. If I remember right, I also adjusted my first developer time to account for the 1-week storage in addition to capacity related adjustment.

    I'm in agreement on being as exacting as possible with color-the whole thing from the film itself to the chemistry is expensive and mistakes are a lot more obvious. I don't even do 35mm color at home-I mostly do 4x5, but use 120 to milk capacity. My 120 sometimes gets lab processed and sometimes gets home processed. BTW, to keep things even in terms of chemistry capacity I usually load two rolls of 120 back-to-back.
     

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