Soft areas in contact print highlights

Hi all,

Reading this thread got me thinking about my contact printing practice, since I sometimes get soft areas, especially highlights. I'm not sure whether it's lack of contact or distance from light source. I use my dichroic enlarger for,light, but have been using it about a foot from the print. I also only use a piece of 1/4 inch glass, not a frame. I just did a test with racking the enlarger head about 4 feet from the print and using bulldog clips to add pressure to the sandwich, and the prints look better, but not by a lot. I'll wait til tomorrow to see them dry and compare. Why would the distance from the light source affect sharpness? Is this tru only of a diffused light? ALso, what does the fact of softness in the highlights mean? All of the above refers to 8x10 contact prints on fiber paper, Kent Bromide and EMaks, btw, deved in PF-130. Thanks in advance,

GB

While the distance to the light source can affect sharpness it really can't affect it to the degree where you could easily see it. The most OOF you could get with a diffused light source is about the thickness of the negative, and also, the effect wouldn't be limited to certain areas. In practical terms the distance and size of the light source are of little consequence, as long as it is far enough away to be even. Your issue is most likely a contact issue, or possibly an issue with the sharpness of the negative image.

The contact being made in the frame is the most likely culprit. Check the glass and the back for flatness. No amount of pressure can make up for a defect in those areas.


EDIT: I see in re-reading your post that you aren't using a frame. What are you using under the glass neg paper sandwich? That is likely the problem. You should consider a good quality frame, if possible.

Jason, I'm using another piece of glass under the neg.

BTW, which frame would you reccomend?

gbenaim said:

Jason, I'm using another piece of glass under the neg.

Click to expand...

Trade it out for some felt or neoprene. This will allow the glass to push down evenly and register the negative to the paper. Most glass isn't perfectly flat.

By all accounts the Bostick and Sullivan frames are quite nice. They are an APUG sponsor, and their link can be found on the sponsor page. Also, I have heard good things about the frames made by Daniel Pelland, of Pelland Photo. I'm sure there are others.

I use contact frames of my own design and construction. I have been meaning to make a few, and offer them for sale in the APUG classifieds, but it has been too cold to work in my shop.

Frame shop

I hear you there, Jason. I've struggled with my shop environment for three years now. I finally got the garage (shop) in Florida heated and air conditioned which was good for both me and the hardwood. Of course as soon as that was under control, I up and moved to Mississippi. Still working on AC for the shop here. Even though I finally got my tools unpacked and set up, I still don't have any frames under way, but I did post a parts kit for do-it-yourselfers, and I plan on posting more similar stuff. I wrote a how-to, with blueprints, if anyone is interested - so feel free to borrow or share ideas on frame building. BTW - thanks for the kind words.
Dan
pellandphoto.com

If you look very carefully at some contact prints from yesteryear you will see the problem you are having is not new.
A vacuum frame will take care of this a lot better than a contact printing frame. As your negatives get larger your out of contact areas show up more. It is much easier to get good pressure across the surface with a vacuum frame than with spring backs, no matter how well built they are.