How to making a Positive ?

[cyrus]

How do you make a positive from a negative?
I need to make a positive from a negative film, using an enlarger I assume a lot like making a regular print except that the developer is D-76 and not Dektol, and of course the safelight has to be off. I guess I'll have to use a very slow film?

[Ralph Barker]

Yes, you've got the basic idea - essentially a "print" on film. Whether you use an enlarger, contact print, or backlight the original and "copy" it with a macro setup depends on the desired size relationship, etc. Choice of "copy" film and developer can vary, as well.

[Michael Gudzinowicz]

Simply use lith film which has a contrast and exposure range similar to B&W paper. Expose for the high values in the positive, and develop for the shadow density. You will have to experiment with print developer dilutions and time for full range positives (slides or back-lit enlargements).

[Eric Leppanen]

In case the negatives have not been shot yet, you could also consider dr5:

http://www.dr5.com/tech.html

I have never used them, so I cannot give a reference one way or the other.

[cyrus]

Thanks - will using lith film create a positive with good details, like the negative?
How is exposure time determined - using a test strip like in prints?

I need to make a positive to be used for photoetching class. They suggest scanning the neg and printing out a positive on clear acetate. However as I plan on doing this at home at some time, I don't want to hassle with a printer.

[David A. Goldfarb]

Ortho film will make a positive with good detail similar to a print.

[Robert A. Zeichner]

The current issue of Photo Techniques magazine has a feature article by Howard Bond on making negative prints. The first step in doing this is making a contact of the original negative (an inter-negative). I have done this numerous times using Howards technique and have had outstanding results. Attached is an example of just such a print.

[Ron Marshall]

Another recommendation for Ortho film. Fine grain and high resolution. Follow Ilford development recommendations to achieve normal contrast:

http://www.ilfordphoto.com/products/product.asp?n=55&t=Specialist+Products

[Michael Gudzinowicz]

Thanks - will using lith film create a positive with good details, like the negative?
How is exposure time determined - using a test strip like in prints?

I need to make a positive to be used for photoetching class. They suggest scanning the neg and printing out a positive on clear acetate. However as I plan on doing this at home at some time, I don't want to hassle with a printer.

Freestyle usually has sheets of lith film in stock. Lith film has an emulsion similar to paper with exceedingly fine grain and a comparable EI of around 4. Most are ortho films (Tech Pan was an exception) and may be used with a safe light - preferably with a dark red sheet of acetate over it if it's an OC filter. Test and handle it as you would paper.

Not all ortho films will work for this application. The lith films have a very high inherent contrast (gammas to 3.0+) and can develop a DMax of up to 5.0 depending upon the product used.