Can anyone provide a thumbnail description of the "unsharp masking" technique, or recommend a source of this information?

Thanks for your help.

-- Henry Friedman (friedlew@worldnet.att.net), March 25, 1999

Answers

In a nutshell: contact-print the negative on to film. This positive image should be lower contrast than the negative, and slightly out of focus ('unsharp'). Then tape this to the negative, and enlarge from the combination.

The effect of the unsharp mask will be to reduce the overall contrast of the negative, leaving local contrast unchanged. You can then print on a harder paper, which has the effect of leaving overall contrast unchanged, boosting the local contrast.

-- Alan Gibson (Alan.Gibson@technologist.com), March 26, 1999.

If you can find some of the literature about making dye transfer prints, there is a section about making unsharp masks, what films to use, how to set up the "sandwich" etc.

-- Tony Brent (ajbrent@mich.com), March 26, 1999.

Look in Photo Techniques magazine. They are big on Howard Bond and the unsharp mask thing. Personally I think carefull focusing and printing would avoid all this tedious work in the darkroom.

-- Jorge Gasteazoro (JorgeGM@msn.com), June 07, 1999.

If you have ever seen a print that has been made with an unsharp contrast reduction mask you will learn to mask most everything you print. The internal or local contrast is excellent and the detail in the highlights is exquisite. Something to behold. I first saw Howard Bond's prints unmasked and right next to them were the masked prints. I was sold. I have since learned to use the mask for lots of images. But for masking to be really effective you need some type of registration system. Condit manufacturing in Connectecut makes a niffty punch and strips. You can set up some kind of guides on the neg carrier but a punch works best.

-- james (james_mickelson@hotmail.com), June 26, 1999.

My experience and conclusions (for 4X5) are the same. There is a real difference, albeit subtle if the mask is not too dense, between a masked and unmasked print. I tried it after seeing prints by Howard Bond done both ways and now mask as a matter of routine.

Two sources of information are (1)Photo Techniques Jan/Feb 1996 and Sept/Oct 1997, both articles by Howard Bond, and (2)Ilford's "Masking and Advanced Printing Techniques ....", catalog #15867. The Bond articles may seem intimidating at first, but a little perseverance will make the techniques he outlines easily repeatable and the results very predictable. He also gives a workshop on masking which I expect is excellent. The Ilford brochure is for Ilfochrome, but parts of it are usable with B&W.

The major problem I find is keeping all of the surfaces (8 excluding the lens) free of dust when printing with a glass negative carrier. Has anyone found a magic solution?

-- Dick Silven (rms@acadia.net), February 21, 2000.

The best description on how to do unsharp masks I found in Ctein's "Post Exposure".

-- Boris Krivoruk (boris_krivoruk@amsinc.com), February 22, 2000.