On Sun, December 20, 2009 13:03, Ruey wrote: > I am going to bale out of this forum for a while. It is not the best > format to present an idea. Not having an ability to provide pictures > and drawings makes it too difficult to explain an idea leading to > excess verbosity and disagreement through misunderstanding. I have an > excellent Kodak booklet on dye transfer that gives a detailed > description for doing both separation negatives from transparencies > and in-camera separation negatives. Here is a quote from the start of > this booklet on dye transfer, I haven't worked in dye transfer myself, but my friend Ctein is one of the people with a freezer full of the discontinued materials. I own around a dozen of his prints, and have seen many more, as well as his inkjet prints. He wrote considerable portions of the Kodak book on dye transfer printing. > "Although more direct methods of making color prints have become > available, the Kodak Dye Transfer Process continues to have important > advantages in many professional applications. It offers unique > possibilities for the control of color balance and contrast, as well as > unexcelled photographic quality." > > I supplied the emphasis. I contend that those words are as valid today as > the day they were written. Dye transfer can be considered a two part > process. It has a front end that consists of making RGB separation > negatives and a back end that consists of "printing" matrices carrying > color dye. That back end process is no longer needed as the latest inkjet > printers from various companies provide very good color reproduction > (Epson K3 inks, MIS K4 emulation of Epson K3 inks at 1/4 the cost, HP 12 > color inks) and in the case of B&W printing, Paul Roark's "Carbon on > Cotton" process comes close enough to photographic print DMAX and is far > more archival (Paul Roark definitely qualifies as an artist/scientist of > the highest order). This is fortunate because the back end of the dye > transfer process was a messy, finicky operation that few could ever hope > to master. It is also fortunate because Kodak no longer makes the > necessary materials to do the back end and I am not aware of other > sources. What continues to be of interest is the front end of the process > which is capable of achieving the highest possible standard of color > reproduction or in Kodak's words unexcelled photographic quality. With > Adobe Photoshop it is completely feasible to use any panchromatic (i.e. > full spectrum from about 400 to 720 nanometer) B&W film with > sufficient dimensional stability to create the RGB separation negatives > because the curves are entirely under your control. Ctein is still doing the full dye transfer printing process, both for his own photos and other people's. His own work is mostly from 6x7 color negative film, so he uses Kodak's Pan Matrix film to get matrices directly from the negative, rather than going through an intermediate separation step. (Ctein has some info on dye transfer printing on his web site <http://ctein.com/dyetrans.htm>.) He's also doing work in inkjet printing, working from scans. Last I checked, his opinion was that dye transfer still gave him better results in the deeper shadows, but that inkjet (he's got a 9800) produces better highlights. So which produces the best print for him depends somewhat on the subject matter. Dye transfer was normally done from color originals. The separations were normally made in the darkroom, from color slides or negatives. Scanning gets that same information out of the original. While it would of course have been possible to expose B&W separation negatives in the field, and then proceed to dye transfer from them, I don't remember that anybody did it as a regular thing (the chance that somebody did it once sometime, as a stunt if nothing else, seems pretty high). If ordinary color negative or slide materials were adequate as a starting point for dye transfer -- then they still are. The separation step, which you pick out as the key piece, and are suggesting is worth continuing while giving up the matrix printing step, is not I think the key thing about dye transfer among the processes available today. Scanning gets the same information out of the materials, and puts it in the same form (separation channels). What made dye transfer *commercially* viable was largely the ability to alter things along the way, which did somewhat depend on the separations. But what makes it *artistically* interesting is the color fidelity, shadow detail, and permanence of the resulting prints, and those all come from the matrix printing step (largely from the fact that the dyes are transferred mechanically, so that they can be chosen for color and permanence with less constraint than dyes that have to be chemically bound into chromagenic paper). Good luck in your projects! Doing things is the best way to find out about them. -- David Dyer-Bennet, dd-b@xxxxxxxx; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info
