Yes, I have heard others mentioning this film in context with enlarged negatives, however the mention always seemed to include the cost of the material. I have encountered several sites that mention enlarging negatives and the materials and methods used. One is David Michael Kennedy, another is John Rudiak, and of course Bob Herbst. The article by Bob Herbst is located on unblinkingeye.com. Bob Herbst's method is the one that I am engaged in now and that is through the use of the Aristo Ortho half tone film. The cost of this material is very inexpensive. I hope that this gives you the information that you require. Good luck.
Lee, also in Unblinkigeye, Ed has an article about making direct positives with ortho film. Seems to me a much better choice to make enlarged negatives, since you go from negative to negative without an intermidiate step.
The extra step may seem to be extraneous, but during the interpositive stage there exists the possibility of burning and dodging, retouching, and contrast adjustment that is not as easily done with the reversal process of enlarging negatives. I am working on contact printing my 4X5 negs to a 4X5 interpositive and then enlarging onto half tone film. The rational is that the contact process in the interpositive stage realizes more of the original negative information. Additionally by doing it this way one only uses one large sheet of film in making the enlarged negative. Good luck and please keep us informed of your experience in enlarging negatives.
Is this halftone film an ortho film, in that you can use it under a red safe light? Is the enlarged film the same material? Are you using pancromatic film at that stage of the process? Just a few questions.
thanks again for all the info,
lee\c who spent all day hanging a solo show
The halftone film is an ortho film, I work with it under the same safelight that I use for enlarging paper. I contact print my camera negative onto a panchromatic film. I have most recently used Delta 400. However I understand that Bob Herbst contacts onto Tri X. And I have encountered others that use Tmax 100. The ideal is to gain an interpositive that appears as a flat print would. In other words detail in the highlights, but grey. Shadows that are not black. The contrast is regained in the enlarged negative. I most recently used ABC pyro at a 1-1-1-15 dilution. Others have used the Windisch formulation at the same dilution. I would think that if I were going to go to a 16X20 copy negative as you are that I would look to working with Tmax 100 as my interpositive for grain considerations. The halftone film as with all litho films does not exhibit the grain characteristics of conventional panchromatic films.
The film is available from Freestyle in California. Costs appr. 40.00 per 100 sheets of 8X10. Cost for 25 sheets of 16X20 are appr. 50.00. Is sold under their Arista brand. And is available up to 20X24 inch size. Chemicals if you decide to go with a pyro formulation are available from Photographers Formulary as will as Artcraft.
Hope that this answers your questions. However should you encounter something not yet addressed, please feel free to ask. Good luck and have fun.
you have been a big help. It will be awhile before I start using this technique. I am in the process of building and then moving and setting up my new darkroom. May be a month or so until I am ready but will contact APUG.ORG and you specfically if I need futher guidance. So far, you have been the only one I have gotten any info from other than a few that said use an imagesetter.