Re: Anyone doing autochrome?
If you were to replace the potato starch with something else perhaps it would be possible. The starch creates a very fine grained random dot color filter - its filters the light on exposure and when viewed. The starch layer and the film were fused together. It might be possible to make something that mimics the potato starch by printing a fine color dot pattern with an inkjet printer. It could be placed in front a negative when making an exposure, the film would be reverse developed. To view the same screen- or perhaps an identical copy would have to be aligned on the negative for viewing. Alignment marks on the screen could be made to make alignment possible. Maybe a film folder that incorporates a autochrome filter ? The Lumiere's had to create a series of very large settling ponds with decreasing currents in order to separate a fine enough potato starch grain. - the starch grains would settle out according to the strength of the current - as the current decreased small and smaller starch grains would settle. A set of settling ponds with slower and slower currents was necessary to isolate the smallest starch grains. These then had to then be flattened with the gigantic press in order for the starch grains to transmit light appropriately. We have much easier ways of making tiny transparent colored dots. There is a good article on wikipedia http://en.wikipedia.org/wiki/Autochrome I believe Jean-Paul Gandolfo wrote a very good article in a photography journal that summarizes the process very well. I don't recall the details - but if someone is very interested I could find it again - our library has a copy. Gord On Wednesday 29 August 2007 12:52:51 pm Barry Kleider wrote: > Thanks to all who responded about doing autochrome. It's been interesting. > > I've decided it's WAY too much like real work. Also, the probability > that a bunch of 10th graders with no darkroom experience might succeed > is in the single digits.... > > <Sigh> I had a wonderful image of seeing their little eyeballs pop out > when I told them we were going to make photos out of potatoes... > > I'm still looking for new tricks, but this won't be one of them. At > least not yet. > > > Barry > > Gawain Weaver wrote: > > Yes, there were many processes like this (it certainly wasn't an > > original idea of mine). John Joly was perhaps the first to put it into > > practice in the 1890s. But McDonough of Chicago was not far behind. > > And later regular screen processes include the Finlay and Johnson > > color plates. Many of these processes involve separate taking and > > viewing screens. This allowed for the inventor to use different > > colors. For example, yellow could replace green in the taking screen > > so that it wouldn't block as much light. Or lighter less saturated > > colors could be used (again for speed considerations, as well as color > > rendition in the final plate). In all of these the screens could be > > mixed and matched. That was one of the main advantages of this > > system---you could make as many as you want. National Geographic > > published color photographs using the Finlay process (I believe in the > > 1930s) and of course a one off process like the autochrome would have > > made this impossible (OK---duplication of autochromes was done, but it > > wasn't pretty). > > > > > > > > I've never actually tried it, but there have been other Photoshop > > autochrome instructions published such as this one: > > http://www.photoshopsupport.com/tutorials/or/autochrome-photo-effect.html > > > > > > > > Gawain Weaver
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