I've recently been doing something along those lines. My goal is to make an enlarged negative for cyanotype printing. The intermediate step, making a transparent inter positive, gives essentially the same result as what you required. The cyanotype needs a negative with a steep contrast slope, But since I need to make a negative from the inter positive, and the contrast increases each time another contact print is made, keeping it in check is important.
I have not attempted this with Ilford's Ortho Plus, and quite frankly, I think it's too expensive. The fact that Ilford doesn't list it as a current product in their catalog makes it a non-starter anyway. Freestyle markets some ortho-litho film which is working out reasonably well for this project. See it here: http://www.freestylephoto.biz/sc_pro...t_id=&pid=1214 . At under $20US for 25 sheets of 8x10, it's not too expensive. Photo Warehouse also markets an even less expensive ortho litho film under their own label which I haven't tried yet. See it here: http://www.ultrafineonline.com/ulhicoorlifi.html .
The material from Freestyle is very contrasty stuff, but that can be controlled by developer choice and development time. My original tests were done using bog standard paper developer, Dektol 1+2, for 90 seconds. The image came up very fast, and there is too much contrast in the inter positive for my needs. It looks ok when viewed on a light box, and could be used if it were to be displayed in that manner, but there is room for improvement. The next attempt used the same exposure, but development this time was carried out using HC-110, 1+63. This was much better, though the highlights were a bit washed out and needed more exposure to preserve some detail. I've received suggestions to use Dektol diluted anywhere from 1+9 to 1+20. That may work. I'm planning to try D-76 1+3, XTOL 1+3, and Rodinal at 1+50 and 1+100 as well. In any case, a very dilute and slow working developer is clearly indicated for this application.
Last edited by fschifano; 10-07-2007 at 08:13 AM. Click to view previous post history.