Looking Sharp

How to effectively sharpen digital images.

- Seth Shostak

IF YOU USE ANYTHING MORE CAPABLE than a smartphone for making photos, then you know all about sharpening.

Well, at least you can find a menu item that, in a fraction of a second, turns “acceptable” photos into snappier snaps. It’s like flush toilets: you may not understand exactly how they work, but you know how to use them.

Sharpening is routine today, and indeed many cameras do some automatic sharpening behind the scenes. That’s particularly true for phone cameras, because the manufacturers know most users aren’t going to download their efforts into Photoshop or something similar and beef up their imagery there.

But sharpening wasn’t always a routine operation. In film days, there wasn’t much you could do to improve the apparent detail of the photo. Once you clicked the shutter and registered the scene as a latent image in silver halide crystals, your picture was as sharp as it ever would be. All that happened afterwards only softened the shot. Chemical effects of the developer would bleed the edges of your subject matter, and imperfections in the enlarger would reduce sharpness even more. Like life after 40, it was all downhill.