daveh
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Post by daveh on Aug 13, 2011 11:20:16 GMT -5
"Is it possible to make a colour reversal film from a BW negative ?"
The answer is, as ever yes and no.
No: I can't see that it would normally be possible to end up with anything that approaches real colour form such a negative.
Yes: This gets a bit complicated, but it is possible, but only if you have colour stock available for the end of the process. 1) first frame exposed on B&W film with red filter 2) second frame exposed with green filter 3) third frame exposed with blue filter.
You now have 3 negatives (hopefully identical - other than the filtration used).
Take the colour film and expose a single frame of it with each of the negatives using the appropriate filter. I did try this years ago with a print as the end result. There isn't much point in doing it really (especially to film). It's a long winded way of doing something that is basically simple (use colour film in the first place).
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Post by Th1nk3r on Aug 14, 2011 5:35:57 GMT -5
Dave,
very interesting experiment ... I will try it someday, after I can get a color print chemical. Or may be I will test the method using PS first..
didon.-
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daveh
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Post by daveh on Aug 14, 2011 10:58:23 GMT -5
Trying it on photoshop is the way to go. In the'channels' panel the picture is shown as RGB and ten each of the three, which just look different shades of a B&W print.
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Post by nikkortorokkor on Aug 15, 2011 3:31:06 GMT -5
Didon, I used Ektachrome and Elite Chrome (the amateur version of Ektachrome) as well as Velvia. I especially liked the price and performance of Elite Chrome Extra Colour, the amateur/consumer version of E100S. I used these films in Brisbane, Australia, which has a sub-tropical climate. I also used E100 and E200 in Thailand during the hot season. I was touring Thailand by bicycle, and so could not refrigerate the film. It performed flawlessly. I carried 30 plus rolls of E100 and E200 (exposed and unexposed) for two months in a bicycle pannier From my experience in Brisbane, which is extremely humid, both Fuji and Kodak E6 products will work just fine in hot and humid environments. The big problem comes with storage of the exposed slides. Treat them like you do your fine lenses, and you'll be fine. Jim Doty's site has some good advice on E6 film choice: jimdoty.com/learn/Tips/Film_Lite/film_lite.htmlMichael.
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Post by Th1nk3r on Aug 16, 2011 13:15:31 GMT -5
Michael usualy how low we can keep the exposed film safely before be processed, because I still have one roll that already exposed in May. thanks for Jim Doty's link, very informative and useful. didon.-
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mickeyobe
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Post by mickeyobe on Sept 8, 2011 5:42:18 GMT -5
Didon,
"is it possible to make a colour reversal film from a BW negative ?"
A black and white negative - or positive - has no colour to begin with. I have never heard of introducing real, natural colour into a B & W negative.
B & W positives have been hand coloured for well over 100 years but the colour is never (Okay, rarely) realistic.
You said "a BW negative?" Dave has described a three negative process that has been successful. I think that is called a "colour separation process". It has been used in making some advertisements in the past. It is a complex, specialized, costly process that can provide beautiful results.I do not know if it is still in use.
Mickey
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daveh
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Post by daveh on Sept 8, 2011 7:10:15 GMT -5
We have a little Canon Selphy printer for doing occasional 6x4" prints - it's a dye sublimation process I think. Basically it is an additive print doing a pass for each of the three primary complementary colours - cyan, yellow magenta. The results are, in most respects, much better than the inkjet type small printers.
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Post by grenouille on Dec 22, 2011 9:57:06 GMT -5
Darkroom work is still very much alive with our local club, that is why I do a lot of B & W and Films are easily avaliable in our local shops. As for B & W photographic papers, it has to be special ordered. Hye
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