How do I get continuous tones from ortho filmgreenspun.com : LUSENET : Large format photography : One Thread
Hello there. I was wondering if anyone has experience using ortho film in the camera for continuous tone negatives.I have done it in the past for producing negatives to print on albumen paper. It was hard to control, but I really liked the results. I would like to try it again. I am getting aqcainted with a sea of new products and replacement products and would like a head start with any advice before I start experimenting. I am curious about exposure and developement. Apercentage of the film speed? Use diluted paper developer? thanks, eugene
-- eugene sykes (firstname.lastname@example.org), December 04, 2001
I have never tried it on camera, but I guess ASA 5 developed in pyro or Catechol will give you continuos tones.
-- Jorge Gasteazoro (email@example.com), December 04, 2001.
Eugene, which ortho film are you considering? Is it Kodalith or the recently discontinued copy film? Ken
-- Ken Woodard (firstname.lastname@example.org), December 04, 2001.
Hi Eugene, I've got experience using said stuff, and what you want to do is buy yourself a box of Ilford Ortho Plus. It is a continuous tone ortho. I develop it in Rodinal 50:1, by inspection of course, but keep it out of direct red light as it is possible to fog it. You might be able to pick up some speed with D 76. Begin with 80 EI, but sometimes I shoot it at 40. I like it just fine. Some folks hate the skies it makes. Good luck, David
-- david clark (email@example.com), December 04, 2001.
'Ortho' is short for orthochromatic, meaning true coloured. It refers to the colour sensitivity of the film, not to it's contrast.
You can get the same effect as ortho film by using a deep Cyan filter on a normal panchromatic film.
If you mean lith or high-contrast copying film, then why not say so?
-- Pete Andrews (firstname.lastname@example.org), December 05, 2001.
If by ortho you mean a lith film, like kodalith, then I would suggest developing the film in a paper devevoper, like dektol, with gentle agitation. I used normal paper dilutions. as I recall processing time was much like paper, about 2 minutes. ISO is slow, I believe I started at 6 and tested from there.
-- Erik Gould (email@example.com), December 05, 2001.
What Pete says about the deep cyan filter is technically true, but the exact effects depend, of course, on which pan film you put the filter in front of and other variables. I've used Ilford Otho-Plus, too, and like it a lot. One advantage over the cyan filter -- and it's a big advantage -- is that, as noted above, you get to develop by inspection under red safelight. By the way, even a very dim red safelight (like 7W bulb in a Kodak bullet) gives excellent illumination once your eyes adjust, which, happily, is just about the time you need to start inspecting. -jeff buckels
-- Jeff Buckels (firstname.lastname@example.org), December 05, 2001.
I'm assuming you are referring to getting continuous tones out of high-contrast lith or document film that happens to be orthochromatic. I've done a fair bit of this in 8x10. The trick to this is giving very generous exposure (most of this film has a nominal ASA of about 5, but I would be quite happy rating it at 2) and using a very weak developer. The generous exposure is quite crucial to giving the shadows a fighting chance of developing some density before the highlights head out to the stratosphere. The weak developer is necessary to exhaust in the highlights. Use reduced agitation. Developers that have worked for me well are TO/XDR4, POTA with glycin, Catechol based developers like the Windisch. If you prefer off-the-shelf, try Technidol or diluted print developers. Good luck, DJ.
-- N Dhananjay (email@example.com), December 05, 2001.