Making a transparent positive.
Sometimes I wonder at the simplicity of solutions to problems -- and then I wonder at the simplicity of the mind that took so long to find that simple solution.
Some of you have been very kind in commenting on my "polygravure" prints and I promised to post more of them. The problem has been that I seemed to need the computer to make a suitable transparent positive to expose the plate. I tried copy machines (too "xerox-y"), I tried litho film (too much contrast the way I did it) and I settled on the compromise of scanning and printing out a photo-positive image on a transparency. I didn't, however, think that posting a whole bunch of them was keeping with the spirit of APUG. I'm experimenting with duplicating film in the camera, but I haven't had a chance to take a photo worthy of a test plate since I worked out the exposure (meter for ASA .8 and then open up two stops seems to work)
Today, I realized that I could contact print a piece of film in the camera if I could get the light right. A 4x5 negative placed face to face on a sheet of Efke 50 in a film holder and a Polaroid press shutter with a constricted throat - 3 cm. At 330 mm extension, that makes it an f11, right? A light box for a light source and voila! No lens meant nothing in focus to interfere with the image. Unlike most of my schemes, it actually worked.
Amazing that it took me so long to figure it out, but then I am a bear of little brain at times.
I'm hoping you'll post some of these new images... I'm working with Imagon right now, having found SolarPlate to be too expensive, and am running into the same problems... I'd like to do a complete analog process, but haven't done enough experimenting. What was the problem with the contrast using litho film? Did you use Ilford Litho Plus? I was going to try that this week.
If you have the time, could you post a pic of your latest process setup?
I'll post some as soon as I get back in the studio. The litho film I used was from Ultrafine (Photo Warehouse.) It's decent film, I just didn't like the harshness of the positive it gave me. I was looking for more mid-tone values than I was able to get with it. This image is made that way. The scanned and printed picture, which I like, but don't think gives me the range I'm looking for, is this one. So far, all I've done with the in-camera duplicating film and the contact printed negative are small test images. I cut up the plates in order to do this all without spending all of my allowance just getting started. I get my plates from these guys. I use the KM73 plates and a "facial tanning unit" that I bought on ebay for a light source. The good positives right now seem to take about 1 min. of exposure and then 1 minute of exposure through a stochastic screen purchased from Dan Welden.
I'm still playing with the process, stumbling along as is my style. Eventually, I get some good stuff. I'll post more when I do.
Something I have been thinking about doing (but, typically, have not done yet) is to produce a large monochrome negative from an enlarger projected colour transparency with the intention of contact printing to paper.
I realise that I would have to use normal film in complete darkness to get a response from all colours.
Has anyone had any success with that method?
"People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.
I haven't gone that far, but using Arista APHS film, I managed to make a decent enlarged B&W positive from a negative:
Originally Posted by Steve Smith
In your case, you could simply copy the original slide onto TMAX film, and process it with a reversal kit. Then you enlarge the B&W positive onto APHS film, and contact print it.
Using film since before it was hip.
"One of the most singular characters of the hyposulphites, is the property their solutions possess of dissolving muriate of silver and retaining it in considerable quantity in permanent solution" — Sir John Frederick William Herschel, "On the Hyposulphurous Acid and its Compounds." The Edinburgh Philosophical Journal
, Vol. 1 (8 Jan. 1819): 8-29. p. 11
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Yes, I did it with tri x 5X7 to make an enlarged negative for pt/pd.
Originally Posted by Steve Smith
It works fine
Try to use Bergger BPFB 18 - in my humbel apionion it is the best halftone copy film on the market, gives you very fine grain and is medium contrast. Develop in D 76 for standard work and D 23 if you have a problem with burned out highlights in your original. Use red safe light.