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rob_calhoun

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Everything posted by rob_calhoun

  1. I have printed Ciba/Ilfochrome prints and they were not that good compared to prints from negatives. They looked good to many because they had high contrast and saturation that made them tend to pop compared to prints from negatives. But such pop does not mean accuracy, and prints from Cibachrome were not as color accurate as prints from negatives due to the dye impurity problems. In addition to my own experience, I have read much about this in the photographic literature. Many experienced Cibachrome printers would have to resort to masking techniques to fix this problems as well as contrast issues and doing so could produce very good prints. This was done extensively in the publication industry to improve color and contrast when printing from reversal film. The motion picture industry has used negative film for several reasons. It has dynamic range recording capability superior to reversal film due to very low contrast. It is masked for dye impurity problems which means multiple generation copies can be made with little color degradation, important for production and distribution. Its low contrast means it can be transferred to print material with better contrast and highlight and shadow detail than reversal film. This would all be totally impractical with high contrast, unmasked reversal film. The print film used for projection has a much higher dmax than any reversal film for better projected dynamic range. The mask is still necessary as there are still many out their who print color negatives optically so it is as important for them as it ever was. Those who scan still benefit from the mask because color will always be better with it than without it. I really can't see relying on it being fixed digitally. That in itself may present problem for users; I believe the best way is just to do it in the negative, and have it already done, for both optical printers and scanners.
  2. I agree with Wilmarco's comments. Personnaly, I use glass canning jars.
  3. The dyes are produced during development in a way that restricts the type used and nature of the dyes and these dyes have color absorption issues that cannot be solved simply by making them better. A mask is the most practical way to correct them. The dyes in reversal film have similar deficiencies or impurities as those in color negative film, but each one has a different purpose and treated differently. Reversal film is meant to be viewed directly or projected; negative film is meant to be printed. When viewed directly as in reversal film, the dye impurities are there, but hardly noticeable as they are only seen once. But in the case of a negative, it is printed onto paper that also has similar dye impurity problems, so the dye impurity problems would be seen twice, and the problem would compound, and the resulting degradation is quite noticeable if not corrected somehow. The correction takes place in the negative because of the mask, so only the dye impurity problems of the paper are seen, and as with the reversal film, they are hardly noticeable. Now, if one tries to print reversal material onto paper, there is no mask and thus no correction in either the film or paper and color degradation is much more noticeable than a print from a masked color negative. Technically, a print from a masked negative is always better than a print from reversal film and is one reason why the motion picture industry generally does not use reversal film.
  4. Kodachrome was difficult to manufacture because the layers were very thin. Although it had a look some liked, it was technically inferior to today's E-6 films as it had crossover and dye impurity problems. The processing was very complex, and very exacting, making it costly and next to impossible to process at home. The chemistry went bad very quickly requiring high volume processing to make it feasible. To start manufacturing and processing it again would be cost prohibitive as the demand just isn't there, and there is no reason for it to be, considering the popularity of digital and the decline of reversal films. Kodak recently did an investigation to see if the market would support the return of Kodachrome and found it would not. Kodak seems to be having trouble getting the new Ektachrome out the door (and it is much more feasible to release than Kodachrome) and its success remains to be seen, so odds are high that the re-introduction of Kodachrome is simply never going to happen.
  5. Actually, no. The overall rate is what counts. The speed of rotary machines is adjusted to give proper overall agitation continuously but the same result can be accomplished with intermittent agitation. I use small tanks and invert once every 10 seconds and get in-spec results as measured with my densitometer. One should run tests with his/her particular developing technique for best results.
  6. Processing C-41 by hand and getting consistency at the proper times and temps is not difficult. I (and many others) have been doing it for years, and I check my results with a densitometer for accuracy. In the past I got worse consistency from labs. You simply cannot process C-41 at low temperatures for longer times and get quality results. For one thing you get crossover as discussed earlier and it would be difficult if not impossible to correct for this accurately with software as well as time consuming. In addition, the DIR and DIAR dye couplers used in the film and process simply do not operate properly at low temperatures to give proper color correction of dye impurities. That too, would be extremely difficult if not impossible to correct with software. That is why 100F is used instead of 75F which the old C-22 process used (before the newer dye couplers), and was what engineers wanted to use originally for C-41, but found the couplers worked best at higher temperatures. I'm not saying don't do it, just be forewarned.
  7. To me it makes more sense to just develop film properly to begin with, and have good negatives, than to have to go in and try to fix them in "post". Just doing it right to begin with (it's not that hard) and you will always have the best quality negatives with the minimum difficulty for optical printing or digital use.
  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. Both b&w and color printing have their issues, but which one is best to start with is debatable. With b&w you have the issue of contrast of the negative to deal with, which can vary with different films and their development, and frequently has to be, but can be, dealt with when printing. With color, contrast is less controllable, but less variable with film, but you must deal with color balancing. It may seem daunting at first but quickly comes with experience, and after establishing starting balances for different films. B&w printing requires a minimum of developer, stop bath, and fixer, but if done in trays you only need developer and bleach-fix for color, and like b&w, can be done at room temperature. Lastly, with b&w, one has to choose from a larger selection of paper types and developers, and if advanced learn things such as divided development and divided fixing, clearing agents, wash aids, toners, etc. With color, there are fewer papers and the RA-4 process is simple and standardized. So if I were to suggest one to start with, or try to master first, it would be color, with less overall variables to learn than b&w.
  10. RA-4 color printing can be developed at room temperatures (e.g., 68F for two minutes) in trays using Kodak RA Developer/Replenisher RT, making it very easy. Drums, fancy processors, and high temperatures are not necessary. The developer is followed by bleach-fix and a wash. If the filter drawer on the enlarger is used, yellow, and magenta filters are used for color balancing. Generally they are made of acetate, not gelatin. For color negatives, you will not use cyan filters. Do not use red, green and blue filters in the filter drawer; it won't work. Red, green and blue filters of good quality, usually gelatin, can be used if inserted in the light path under the lens one at a time. Color balance and density is adjusted by varying exposure time with each filter, but this is the most cumbersome way to do it. As discussed earlier a color head is the easiest, but more expensive way.
  11. A book was released a few years back by a former Kodak employee, Bob Shanebrook, about how Kodak manufactures film called "Making Kodak Film". Should be plenty of info there.
  12. I shoot mostly color negative film and develop and print it in my darkroom. All formats, but mostly 120. I do some b&w occasionally, all 4x5. No digital. B&W is fun and some subject matter lends itself well to it, but as the world has color, that is what I prefer and am learning to master both the shooting and darkroom aspects of it.
  13. <p>Not only does the film need the remjet removed, but movie negative film has lower contrast than consumer still films, and requires ECN-2 processing for proper results, all of which makes it difficult for general consumer use.</p>
  14. <p>Interesting, though, that they are considering bringing back other films. Or so they say.</p>
  15. <p>Official policy? Could you provide a link to an official source saying this? I recently read a newspaper article saying T.J. Mooney, a spokesman for Kodak Alaris, has said that they considered Kodachrome, but decided Ektachrome was the better choice, so that is returning. The return of Kodachrome would have too many problems to overcome and need too much money to restart; demand is uncertain. Even the success of the return of Ektachrome, which is much more feasible, is questionable.</p>
  16. <p>Supposedly this has already been done a few years ago buy an Australian named Stephen Frizza. I read about it on APUG.ORG.<br> <br /> I don't see the point, Kodachrome being an obsolete film. Considering the complexity of the process, I can't see anybody doing it for money unless they charge an arm and a leg with the chance of poor quality resulting. Anybody having any Kodachrome left can get it processed in b&w, much easier and cheaper.</p>
  17. <p>As I understand it there are technical problems that prevent any of the previous Ektachromes from coming back in their old exact form so the new film will be a reformulation. To reformulate and test will take some time so that's why the delay. </p> <p>Bringing back the old Kodachrome is far more problematic as no one currently develops it anywhere. It was a very difficult, complex process (different than Ektachrome, which is much easier), and some of the chemistry is not even made anymore. Kodachrome had technical problems that were partly responsible for its unique look that some liked, but most would prefer the technically superior E6 films of today.</p>
  18. <p>Sorry, in a hurry and forgot to say that I was explaining a more tradional way of dealing with slides, and today the problem can be dealt with using software after scanning slides.</p>
  19. <p>Karim, for publication and stock libraries, slides are generally preferred because they are a positive image and content easily evaluated compared to a negative. However, unlike color negatives, color slides are not masked, and before being published, color correction must take place, generally in the form of making masks to correct for dye impurities in the slides, otherwise color will be degraded <strong>when printed</strong>. (Color negatives have such dye-impurity correction built right into them giving them an orange color, and better image color when printed.) Masking must also be done to lower the high contrast of a slide. Publishing outfits will have a department set up to make and use such masks for all slides being published. </p> <p>Therefore, slides can be and are used for publication, but that is not their intended purpose, and as a result a bit of work must take place before publication to use them.</p>
  20. <p>Naturally, pros who had used transparency films found digital faster and more productive for their intended uses, but not necessarily better quality, at least without manipulation. The intended use of transparency film is projection, and that is where it really shines over digital. Not many pros used it for that. As for the typical consumer, they're happy viewing their photos on a smartphone.</p>
  21. <p>Negatives are intended to be printed. If you print a negative and use masking, or dodging and burning techniques, all the higher dynamic range that the negative has recorded can be transferred to the print.</p>
  22. <p>Chrome film does not have the dynamic range of negative film and is why one must be more precise with exposure, to preserve highlight and shadow detail. I don't see how anyone considers that a nice thing. Negative film is more forgiving, therefore one can get a quality image over a wider range of exposure. Not that I am against chrome film, it is great for projection, its intended purpose.</p>
  23. <p>According to Kodak Alaris's recent press release, the Super 8 version will be sold as well.</p>
  24. <p>I use canning jars. They are glass, which is better than most plastics since you want something absolutely impermeable to oxygen for developers and fixers. They also have very tight seals. They come in different sizes and are reasonably priced, at least where I live. My chemistry, color and black & white, lasts months, even years, in them.</p>
  25. <p>Time and time again I see people posting images and saying or implying, "See my great results?". What I see means nothing. You simply can't judge the quality of an image by a scan. Scanners, monitors and all processing in-between affect the image.<br> <br /> That said, what I see does not look right; colors look offish, especially skin tones and pavement. I would need a print to look at to see the true results. But believe me I have done plenty of testing with low temperature C-41 processing, measuring for crossover and the results were always out of manufacturer's specs. More importantly, you could see the crossover in the prints, and it stuck out like a sore thumb when compared side-by-side with prints made from negs done at the correct temperature.<br> <br /> The major film makers never have produced a kit for developing C-41 at room temperature, and this is the reason why. The process does not, and is not designed to produce optimum results at low temperatures. The results may be acceptable to you, but likely would not be acceptable to others. I urge any who are considering trying it to compare it with the real thing and see whether it is acceptable to them before committing to it.</p>
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