Help! My contact prints are less sharp than original film

[cotdt]

I need urgent help! I got what first appeared to be gorgeous contact prints. Contrast and tones are excellent, and under the naked eye the detail was nice as well. Unfortunately this was just an illusion, because under my 22x loupe, the contact print was clearly less sharp than the original film. What am I doing wrong?

I did my contact prints the usual way, by putting a peice of glass over the negative, emulsion side down onto the paper, and using diffuse light. I'm using Ilford RC Multigrade IV paper, Dektol developer. What am I doing wrong? Why is there less detail in the contact print?

[SAShruby]

Diffusion of light, try to increase distance between light source and contact. 8ft or so.

[David Vickery]

What size is your film????

Diffuse light sources are going to produce a less sharp image than a point source (a single light bulb will be sharper than a fluorescent tube).

How many people do you expect to view your prints through a 22x loupe?

If you are printing 8x10 or smaller then the thing to change is the light source. A simple light bulb of 100 watts to 300 watts will work fine. If you are printing larger than 8x10 then you need a vacuum frame.

[cotdt]

So the issue is the diffused light? What would make a good uniform point source light? All the light bulbs I have have irregularly shaped points of light that is far from uniform.

[domenico Foschi]

I can understand that diffused light might have an effect on an enlarged negative, but how can it be influential in a contact print?

[Asher Kelman]

I can understand that diffused light might have an effect on an enlarged negative, but how can it be influential in a contact print?

If one would use a milky glass cover over the negative, then, of course, one would have very diffuse light with thousands of light sources at very short distances from each grain of silver. So there will be multiple short shadows from each silver point and so the print will be less sharp. Of course, this is a most extreme case, but anything but a point source and great distance, will give multiple shadows,

Asher

[Joe Lipka]

David - REAL Photographers will look at every photograph with a 22x loupe. REAL photographers will always have their nose up against the glass looking at a photograph.

Seriously, though, I would suggest that you need to get the glass, negative and printing paper as close together as possible. Some choices to do this would be:

Spring clamps to hold the glass/negative/printing paper/masonite backing "sandwich" together.
Contact printing frame.
Vacuum easel.

You did not mention whether the print was wet or dry. A dry print would not have a swollen gelatin emulsion on the surface. That might make it look unsharp.

[Bjorn Nilsson]

The "modern" answer: A strong white or blue LED would probably be a very good candidate for a point source light. As the nature of LED's are that they emit a light ray which is spread by a lens, one could grind the top off the LED to make a flat 1/8" point light.
A more classical answer: Any relatively small lightbulb with clear glass will do. Even if the filament thread isn't point shaped it would be small enough to act like one if you have it e.g. 3 - 4 feet or more from the glass/neg/paper sandwich. At least that is what is commonly used by many contact printers, like e.g. Brett Weston and others. I think I read somewhere that small oven bulbs or fridge bulbs were weak enough to give enough time to dodge and burn when neccesary.

//Björn

[Robert A. Zeichner]

I don't think you've done anything wrong. I think you may be expecting more from the paper that it can possibly deliver. Film is designed for magnification and as such, has far greater resolution than paper. The paper is the final product and depending on the size of the print, will be viewed at anywhere from 10" to a few feet. I can't even focus my eyes at 10" anymore and I'm sure I'm not alone. Some years ago I designed a testing system for ground glass/film plane coincidence and did all my tests with B&W negative film. Someone asked me if I had ever tried it with Polaroid to save the time and trouble of processing. I hadn't, so I did and it didn't work for the very reason I explained above.

[Mark Sampson]

There have been numerous threads about the resolving power of photographic paper. It seems to be a complex subject, at least I didn't try to understand it fully. But I seem to recall that paper only has a resolution of 10 lines per mm or so- much less than film. But I'd check neg/paper contact, and light source issues, as stated above, before worrying about paper resolution.