help with contact printing

[wclavey]

An enlarger is a great point source for contact printing. The only thing diffusing it will accomplish is to lower the output, and eliminate any spots from giant dust on condensors, assuming you could focus them. I'd rather clean the condensor. If your enlarger is so out that the light needs to be diffused to be even, well, that could be... I've had one like that

If you need to slow it down, stop down the lens and/or raise the head.

It also removes scratches that may be in the glass of your contact printing frame. When I first started contact printing my 4x5 negaitves, I was using the ceiling light in my small 1/2 bathroom as my light source and used the diffusion screens I described above to control the amount of light. But then I switched to a 7 watt light source about 3 feet above the toilet seat top and eliminated the diffusion screens ... and started getting scratches in all my prints... surprisingly all in the same place, yet I couldn't find any scratches on the negatives. Thats when it dawned on me that the diffusion screen layers on top of the frame were eliminating the scratches in the glass.

[JBrunner]

It also removes scratches that may be in the glass of your contact printing frame. When I first started contact printing my 4x5 negaitves, I was using the ceiling light in my small 1/2 bathroom as my light source and used the diffusion screens I described above to control the amount of light. But then I switched to a 7 watt light source about 3 feet above the toilet seat top and eliminated the diffusion screens ... and started getting scratches in all my prints... surprisingly all in the same place, yet I couldn't find any scratches on the negatives. Thats when it dawned on me that the diffusion screen layers on top of the frame were eliminating the scratches in the glass.

True. I had an old contact frame with scratches and pits that caused similar problems. A diffusion screen directly over the frame would send light under the scratches and minimize or eliminate them. Instead, I just had a new piece of regular glass cut, it was something like $3 bucks. As long as your springs are strong you shouldn't have problems with regular glass, but I have heard of some persons in humid areas where newton rings are more prevalent using a lightly frosted glass that still lets them see the neg. I wonder if that awful no glare framing glass would do the same thing? I would have trouble with a diffusion over the frame, as then I couldn't see to dodge and burn.

[wclavey]

True. I had an old contact frame with scratches and pits that caused similar problems. A diffusion screen directly over the frame would send light under the scratches and minimize or eliminate them. Instead, I just had a new piece of regular glass cut, it was something like $3 bucks. As long as your springs are strong you shouldn't have problems with regular glass, but I have heard of some persons in humid areas where newton rings are more prevalent using a lightly frosted glass that still lets them see the neg. I wonder if that awful no glare framing glass would do the same thing? I would have trouble with a diffusion over the frame, as then I couldn't see to dodge and burn.

I switched to using just a piece of new 1/4 inch glass, but I really liked using the contact printing frame, especially since I am not using a real darkroom and the frame helped hold it all together. And I liked being able to dodge during the printing process, which I can't do with the diffuser in place, as you identified.

I can't figure out how to get the old glass out of the frame. For now I have taped off a section of the frame that is scratch-free, but it forces me to use the lower left hand corner of the 8x10 sheet rather than the center, and I would not be able to use a larger (5x7) negatives.

[loman]

Thanks again for all your replies.
I just got a little wiser... nice!
Best Regards
Mads