View Full Version : How can contact prints be out of focus?

6-Oct-2015, 19:26
I have some paper negatives that are sharp, yet the contact prints have out of focus areas.
Any ideas?
I used a piece of white mat board on a formica countertop, put down the paper, then the negative on top of it with a piece of glass on top of that.

I put some of the pictures in the paper negatives thread so if you want, you can see them there.

Jon Shiu
6-Oct-2015, 19:29
Have done them wet, for better contact.


Fr. Mark
6-Oct-2015, 21:13
Put felt or two on a piece of 3/4" plywood, use 1/4" or thicker glass and a bunch of clamps around the edges. I've had it work well up to 8.5x11 digital negatives and 8x10 in camera negatives.

For bigger I think people use vacuum easels or other more complex designs.

How does wet work? I'd be afraid the two touching emulsions would try to become 1 emulsion like in 4 color carbon printing.

Fr. Mark
6-Oct-2015, 21:14
Weight of glass may not be enough. Mat board may not be flat enough nor squishy enough. Hence felt and clamps approach.

John Olsen
6-Oct-2015, 21:15
Yes, contacts can be out of focus. Heavier glass could help, along with gentle weights on the edges. I got some 1/2" glass and the contact definitely got sharper.

Oren Grad
6-Oct-2015, 21:29
Another voice in the chorus: most likely not enough weight. Also, I wouldn't use a mat board as the base for the sandwich - I'd use a piece of glass. If you need a mat board to block light and prevent a pattern in the countertop from printing through, put a piece of glass on top of that, so that the sandwich from top to bottom is heavy glass, negative, printing paper, glass.

7-Oct-2015, 03:58
The white matboard could be diffusing light, use something light blocking. That's why b&w printing easels are yellow. If the sandwich moved it would create focus issues. More weight is good too.

N Dhananjay
7-Oct-2015, 04:01
Some possible culprits...
1) Lack of weight or force holding the sandwich in close contact
2) Some dirt serving to separate the neg and paper in some areas, even under pressure
3) An error in making the sandwich - has to be emulsion to emulsion, if you have the base side of the neg against the paper, you can get some softening
Cheers, DJ

Jim Jones
7-Oct-2015, 06:39
If the negative is naturally flat with no kinks or curls, a soft foam rubber or felt pad should work well behind it. If the negative will not naturally lie flat, perhaps a firmer backing and lots of pressure is needed. A large light source close to the negative aggravates any problem of separation between the negative and print. A small bright distant light source reduces the problem. In graphic arts, we used vacuum tables to apply maybe 20 lbs of pressure per square inch, but sometimes had several layers of film to shoot through. That small bright distant light source helped. For duplicating negatives on diazo film, a large and very intense light source was used fairly close to the film. Maintaining intimate contact between negative and raw film became essential.

Paul Metcalf
7-Oct-2015, 07:49
You are putting the paper negative with the image side against the contact print paper, right?

7-Oct-2015, 08:49
You are putting the paper negative with the image side against the contact print paper, right?
Yes. Most of the print is sharp, there are just some areas that are soft.

7-Oct-2015, 15:14
I could not get Ilford double weight fiber base flat and in contact with a negative using a large stack of glass. Eventually gave up and got an enlarger.

7-Oct-2015, 16:46
Blurry areas can happen with wet contact printing too... fiber paper works a little better in that regard. It only takes a little variation in pressure to make a soft blurry area on a contact print. I've had best luck dry contact printing in a good printing frame, which is fussier than just laying a sheet of glass on top. Am planning to get some heavy glass to try soon....

7-Oct-2015, 17:16
Yes. Most of the print is sharp, there are just some areas that are soft.

What are you using for a light source?

Do not use a frosted light bulb, use a clear one. This is because you want to get as close to a point light source as possible.

Also, along these lines, you would want the clear light bulb several feet away. For example, 3 or 4 feet.

Daniel Stone
7-Oct-2015, 18:32
I found that using a vacuum frame gave me the sharpest contact prints I've ever had. One day in the future, when I revive my darkroom when space is more permitting, I'll invest in a vacuum frame setup like I had before. Nothing quite like it!

However, a quality contact frame will work (almost) as well, but IMO, a vacuum frame is superior, if you have the space to allocate for such a setup.


8-Oct-2015, 02:53
I use an very nice contact frame made by René Smets (https://www.google.nl/search?q=print+frame+Ren%C3%A9+Smets&source=lnms&tbm=isch&sa=X&ved=0CAcQ_AUoAWoVChMI2pyu4cuyyAIVRTwUCh3pfgMS&biw=1280&bih=913#imgrc=1OVVbkQt4w0nqM%3A), see also



Darko Pozar
8-Oct-2015, 03:35
Utilise a light bulb with the silvered part on the neck of the bulb. A vacuum frame is ideal...make sure that the noise of the pump is not a distraction with the appliance outside the darkroom running a long hose to the vacuum frame.