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  1. #11
    Photo Engineer's Avatar
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    Just FYI, films at EK are made to fit the developer, not the reverse of course.

    Therefore all films fit one developer. But, I have designed up to 12 developers that gave the same results with one color product, but when I changed emulsion #s of the same product I got 12 answers even though the two emulsions matched in the product developer.

    This whole area in color is a mine field. B&W can be the same.

    PE

  2. #12

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    Quote Originally Posted by Photo Engineer View Post
    Just FYI, films at EK are made to fit the developer, not the reverse of course.

    Therefore all films fit one developer. But, I have designed up to 12 developers that gave the same results with one color product, but when I changed emulsion #s of the same product I got 12 answers even though the two emulsions matched in the product developer.

    This whole area in color is a mine field. B&W can be the same.

    PE
    To digress slightly.
    I have been using Paterson liquid one shot C41 developer. According to the instructions with the developer each 100cc of diluted developer ( 1+2) will develop a 35mm or 120 film ie 300cc will develop 3 x 35mm films albeit with extended times. Quality seems OK to me - far better than scratched films from High St minilabs.
    Question is will the extended dev times reduce quality and is this dev suitable for all C41 films. I have done some films this week but have not yet been able to print them. I can't read colour negs at all well but the XP2 looks OK.
    Cheers
    Jeff

  3. #13

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    Quote Originally Posted by Photo Engineer View Post
    Just FYI, films at EK are made to fit the developer, not the reverse of course.

    Therefore all films fit one developer. But, I have designed up to 12 developers that gave the same results with one color product, but when I changed emulsion #s of the same product I got 12 answers even though the two emulsions matched in the product developer.

    This whole area in color is a mine field. B&W can be the same.

    PE
    I should have mentioned in my previous post that I have used Tetenal C41 tabs which I liked because they included stabilisor but they seem to have disappeared from the market. Anyone know whether they are still produced?
    I get the feeling though that small kits of C41 are doomed and I'll need to learn how to mix chemicals but with rather more accuracy than when I mixed my own D163 about 45 years ago!
    Cheers
    Jeff

  4. #14
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    As you use a developer, it has a buildup of oxidation products, halides and restrainers. Extending the development time will often get the curve shape back up to normal, but at the same time the sharpness, grain and color reproduction may gradually deteriorate. This is called seasoning, and the best way to overcome it is replenishment.

    If you do use a developer over and over again, it will be ok for a short time, but will eventually yield degraded results.

    The old stabilzer is about 3% formaldehyde solution with a drop of Photo Flo 200 in it. The new stabilzer is proprietary and cannot be used with older films. The old stabilizer can be used with all films AFAIK.

    PE

  5. #15

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    Quote Originally Posted by Dave Miller View Post
    I've only just picked up this thread again, so apologies for not replying earlier. I haven't seen Michael Maunder for several years. I thought that he had retired to the Channel Islands to indulge in his passion for astronomy, and had given up the production of chemical kits. I should address your question to Martin at Silverprint in the first instance, if you haven't already done so, and ask him to relay your question.
    The report of Michael Maunder retiring to the Chanel Islands was reported in a copy of Mono magazine. I contacted him and he replied stating he had been retired for many years and what did people think he was doing all that time?
    He is currently in New Zealand until December observing the transit of some planet. (Mercury I think). He is still making photo-chemical products for Silverprint and Retrophotographic.

  6. #16

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    Keith If he is in N Zealand I could wait a while for an answer to my question about the reduction in dev time for rotary processing and Silverprint could wait a few weeks for anymore kits.

    I am still hoping that someone has used Celer 41 and can tell me about their experience of dev times.

    I must admit I hadn't expected to see a comment about a 25 - 30% reduction times for dev if using a rotary processor. Other than that everything about it seems as per other C-41 kits. OK the blix is a little shorter than Tetenal or Paterson but I could live with giving the Celer -41 blix a little longer to make sure.

    I have just read the Paterson instructions again. Interestingly it gives the same hand agitation pattern as Celer-41 and the same time of 3mins 15 secs. It makes no mention of rotary processing at all. It hadn't registered with me that it didn't cover rotary processing. So when I used Paterson I just gaily went ahead with rotary processing at 3 mins 15 secs and made no reduction allowance for rotary processing. The negs were fine.

    So ignorance was bliss as it were. This and PE's advice to stick with 3 mins 15 secs makes me a little more confident about ignoring any reduction for rotary processing but a statement from someone to the effect that he/she rotary processses with Celer-41 at 3 mins 15 secs without any detriment would still be helpful.

    pentaxuser

  7. #17
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    I would like to point out one uncertainty that has been bothering me.

    If a C41 developer is to work at lower than 100F, then it must be designed with higher activity. I'm uncertain how the average films will react to that, but as I said, overdevelopment is better than underdevelopment.

    Also, even development becomes more difficult with shorter times.

    Good luck.

    PE

  8. #18

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    Quote Originally Posted by Photo Engineer View Post
    I would like to point out one uncertainty that has been bothering me.

    If a C41 developer is to work at lower than 100F, then it must be designed with higher activity. I'm uncertain how the average films will react to that, but as I said, overdevelopment is better than underdevelopment.

    Also, even development becomes more difficult with shorter times.

    Good luck.

    PE
    I have turned up a couple of things as a result of my searches. The Paterson dev which as I understand it, was made by Champion,covers development down to 90F and up to 104F. The range of dev times is from 2mins 40secs to 5 mins 55secs. These are all for a hand agitation of first 20secs( Celer 41 30 secs) then 5 secs every 30 secs( same for Celer 41)Both Paterson and Celer 41 state that the choice of processing temp does not affect neg quality but Paterson says that it may cause some change in print filtration. Both directly or by inference indicate that having found the "right" process, you should stick to it for consistency and certainly in explaining the step by step process Celer-41 uses the 100F which by definition is standard processing

    Tetenal doesn't give a range as such but does say that "Processing should be done at 86F if standard development at 100F produces uneven results" Dev times increase to 8 mins. It doesn't give any clue as to why 100F should produce uneven results or why 86F will fix it.

    It then describes rapid development at 113F. This is one shot only and takes only 2mins. So I'd assume that at 113F something happens to the dev that makes it unsuitable for using again whereas at 100F you can re-use the dev.

    I have only ever used Tetenal to do 2 films consecutively but the instructions suggest up to 4 with no change in time. 5 litres of working solution will do 60 films if the ISO is 400 or greater and 80 if 200 or less. I presume this part of the instructions apply to mini-lab type processor but at 2-4 films per 250ml in a small JOBO tank these figures seem comparable.

    The 5 litre Tetenal kit would be very economical if there was any chance of me going through that amount of films in the 12 weeks that opened concentrates last.

    Interestingly Tetenal specifically mention only rotary processing.

    So it would appear that a number of kits will operate at other than 100F but only Celer 41 seems to cover temp as low as 68F.

    pentaxuser

  9. #19
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    If color balance changes, then the speed relationships between the layers have changed. If those change, then contrast changes as well as color rendition. This is not a position that I would want to be in! Something is going wrong regardless of the fact that you can do it over and over and over.

    The film was built to a daylight balance and if that is upset, then the entire scheme of things internal to the film has gone awry. I suspect that the tests that the developer designers used, or the types of films they tested were insufficient to reveal the nature of any problems.

    With a daylight exposure, all 3 layers should have matched speeds and matched contrasts with the same shoulder and a fixed aim dmin. If it does not, then the masking does not work and you see crossover in the prints.

    I would not tolerate that when I ran my processes nor when I made my own coatings. It messes with the pictures that I worked so hard to get.

    BTW, a badly designed blix can mask this type of problem by leaving a lot of silver behind, which reduces color saturation to the point where the problems seem to go away.

    PE

  10. #20
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    Hello pentaxuser,

    I haven't used the kit you are refering too but, there is another powder C41 kit made by novadarkroom.com called NovaProSpeed 41. It is a 1 litre kit to process up to 12 films with temperature and time details including pull/push.

    I have used this and have a couple of kits at home; I wait until I've got sufficient films to use a full kit. I think its about £11.50 + pp.

    Regards Daniel
    Last edited by simulatordan; 11-20-2006 at 01:39 PM. Click to view previous post history. Reason: spelling

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