Greg's experiments have been so well conducted that I have had to modify many of my statements on fixing and washing as the results he got were clear and undeniable.
But, there is one thing common to Greg's data and your process data. That is image stability. Processing in coffee will not change the overall image stability of a B&W image. It is, after all, Silver! However, fixing and washing tests have the disadvantage of changing image stability and this may not be apparent for years. The use of a hypo test kit and a silver test kit will help pinpoint any residual problem.
In color, the change in image stability by using CD-4 instead of CD-3 cannot be tested except by draconian, lengthy and expensive tests. You are introducing this type of problem. In addition, the change in dye hue cannot be easily tested except by the use of a spectrophotometer. Again, this is something that our eyes may not see well in the film or paper print, but does surely degrade (or substantially change) color. So, your experience at "good" pictures might not pass the test of time, nor that of a good eye for color.
Does this mean you have conducted densitometry on your method? If so, what were the results? Did it meet C-41 standards?
Originally Posted by David Lyga
I have experimented with Dignan's room temperature divided developer for color negatives and while the results may be acceptable to some, I conducted densitometry on the results and the cyan curve had low contrast that was visible to me in the prints, along with overall low contrast. This certainly would not be acceptable to many. And the results varied from film to film. I can only imagine what your method is doing to the curves.
That is a good point about densitometry. I will run a C-41 control strip with the test shots in each process and read them on my densitometer for those that are interested.
Run an RA4 test strip in the C41 process as well, using David's suggested workflow.
I might as well. In for a penny, in for a pound. I should note that I do not have a reflective densitometer. We can glean a lot of information from visual inspection, but not precise densotimetric readings, unless someone else wants to read it after I process it.
Last edited by Greg Davis; 08-01-2011 at 04:02 PM. Click to view previous post history.
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PE, I have no issue with you concerning the theoretical underpinning on CD-3 vs CD-4. But I do have prints made over the past ten years and can honestly say that there has been no change in hue or contrast. Maybe what Kodak says publicly is overly conservative and, in the back room, they know that people like myself will want other ways to work and so make 'slack' into their formulae. I do not know but that is a possibility. Of course the color prints are not kept in sunlight, as we all know not to do.
Note: bleaching slightly lowers contrast but also provides a somewhat thinner (easier to print) base. Sometimes if contrast is deficient (too little exposure) I stop with the first fix and print like that.
All the posted stuff having gotten me riled might have provided a definitive answer to a problem I had been having: sporadic 'greenish base' problem for years, cropping up unexpectedly, and was driving me crazy. Yesterday I decided to find out once and for all what the problem was. The negs are still printable with a greenish base but I hated the sickly green cast. And lately it happened more than not. I knew that it was not a contamination problem and I knew that it was not a light leak problem. PE, I need your confirmation here on the following finding:
I finally thought and thought about this and tried to mentally assert that the problem might be with the rehalogenization. PE, when one uses Potassium Ferricyanide (PF) solely in solution without fixer, should that bleaching be done in the dark? Might this slight fogging I was experiencing be analogous to when one places a piece of unexposed BW paper under light and about 15 minutes later it starts to turn slightly brown without development? When silver metal is turned back into salts (halides) should the process be done in the dark? I think yes now. Yesterday I tried several processing episodes with color negs and purposely after fixation, made sure that the bleaching was done in total darkness. Then, also in total darkness I refixed for a minute, then room light. Each and every time the base was beautiful orange as it should have been. Did I find my answer PE (or someone else with such theoretical knowledge)?
Clarification about my work flow: first when I say that you can store the dev indefinitely I mean any dilution you wish: either concentrates themselves, dilution per Kodak, or MY dilution (which is Kodak's dilution plus four times water). It makes no difference and partial quantities are, of couse, OK. Just always remember that the part A and part B MUST be air tight (filled to the rim of the soda/juice plastic bottle; use glass marbles or use tiny 50ml liquor bottles, with the metal caps, to even out the odd amounts). Part C is not vulnerable to oxidation but should NEVER be stored in plastic soda/juice bottles as the extreme alkalinity will eat away at the plastic: either store in glass or in the original Kodak container. Of course, mixed per Kodak or mixed per David Lyga will allow storage in the soda bottles.
Affirmation: again, my agitation is 'ferris wheel': the plastic tank is half filled and turned on its side in a tempered water bath (105F) and continuously turned on its side during dev, stop, fix. After fix, I inspect (magnifying glass with neg held up to a light bulb) the negs and cut them into three frame lengths (I like these shorter lengths). Then, without even rinsing, I turn off all lights and place them in the PF bath, one 'three frame' lenght at a time. I use a small, plastic 'tray' that a pen and pencil set came in and measures about 1.5 inch by 6 inches. I need only about 20ml of the PF bath to do the whole roll. It is a bit tedious but not difficult. Why use a pint of PF bleach to do what takes far less? (Not affluent here!) Then refix for about a minute in the SAME fix. Then lights and final inspection, wash, last rinse few drops of wetting agent or dish liquid, then dry by hanging up above bathtub.
For printing paper (80 F) , my dilution works fine: use 2 to 3 minutes at ambient (MY 'ambient' is 80F as I am always cold). CAPACITY: do not even try to use less than an average of 100ml of MY dilutions per 80 sq inches of paper. A little more is maybe better. My stop bath for ALL PHOTO PROCESSES (color, BW, film, paper) is only 0.5ml glacial acetic acid per liter (or 18 of the 28% acetic acid per liter). At these incredible dilutions the job is well done but do not try to use, again, less than the absolute minimum of 100ml per 80 sq inches of paper or film.
For those buying the dev/repl RT this following will be very helpful for mixing:
the 10 liter size (makes 50 liters according to my dilution) has the following concentrated quantities in ML: A is 500ml, B is 230ml, C is 500ml
the 25 gallon size (makes 125 US gallons according to my dilution) is: A is 2370ml X 2 = 4740ml total, B is 1422ml X 2 = 2844ml total, C is 2370ml X 2 = 4740ml total
Obviously, living in a 12 ft X 12 ft efficiency I do not mix all at once!!
Astute observers will note that the 'B' proportion is slightly different between the 10 liter size and the 25 gallon size. Why? don't know but I double checked and it is: on the 10 liter size the B has less than 50% the volume as A or C. In the 25 gallon size the B has MORE than 50% the volume as A or C. Just that way.
Also, please note that my recommendations are not the Rock of Gibraltar: they can be tweeked. For example you can dilute even further and give more time or dilute LESS and spend less time developing. I like to push things to the limit and see how much I can 'extract' from a process. This developer is very potent. - David Lyga
Last edited by David Lyga; 08-02-2011 at 08:50 AM. Click to view previous post history.
If you're spending hard-earned money (not to mention precious spare time, which can't be replaced...) on equipment, travel, film and paper, model fees, and all the rest, it doesn't seem logical to run the risk of messing everything up by not the using correct chemicals and procedures for processing.
(I understand, of course, that some people enjoy experimenting as part of our hobby. I do too, (in my case trying out long-outdated and obsolete films), but I keep that as a totally separate interest from trying to produce the best photographs I can.)
Oh, rest assured that I use only a tiny part of what I buy for 'experimentation' before I mix the whole lot. For example, someone wanting to try my way without wasting material can buy the 10 liter size, then draw out only 5ml of A, 2.3ml of B, 5ml of C and make only 500ml of MY developer. If decided that this is 'not the way to go' he still has most of the unadulterated developer concentrates to mix per Kodak. Likewise, when testing either film or paper I do not check whole rolls or whole sheets, but only a tiny part: maybe an inch of the film or a 2" X 2" piece of paper. Same results; far less waste and cost.
I think that you would be very surprised to see what I can get out of Vericolor that 'expired' in 1983. (I also pick up pennies from sidewalks but never stiff waiters or cab drivers when I have to indulge in such: it is called 'frugality' vs 'cheapness'). - David Lyga
You seemed to have solved your "greenish base" problem by fixing, bleaching, then fixing again. Why don't you do just it the correct way and bleach first, then fix?
Ferricyanide, when placed in contact with developer, gives instant FOG due to oxidation and coupling. Therefore ALL color processes that use Ferricyanide must use a good wash and clear after the color developer. This clear is an acid stop bath with some Sulfite in it.
The Ferricyanide must always contain Bromide and is best when acid.
And, when conducting image keeping tests, I have had people swear to me that the image was unchanged until I showed them a check example that had been frozen while the test print had been stressed with light, heat, humidity or all 3.