Accessories


AF Calibration Made Easy (and Inexpensive) [Tech Tuesday]

March 31, 2015

By RF Staff

According to this very cool video, Stanley Kubrick sometimes requested 10 copies of a lens so he could select the most accurate piece of glass for his films. While few—if any—of us have the same kind of clout (and optics quality is more consistent than it was when glass was ground by hand) we still need to tweak focus to ensure that each lens delivers the best possible sharpness.

FocusPyramid-ProductShot-720px

While there are relatively pro-level devices to calibrate lenses, as well as print-it-yourself calibration options, Focus Pyramid falls somewhere in the middle. Designed by photographer J. Cristina, Focus Pyramid is, as the name implies, a pyramid-shaped tool that aids in assessing and correcting any autofocus inconsistencies and inaccuracies.

Die-cut from coated, heavyweight paper, it takes just a couple of minutes to fold and insert the well-marked tabs into their respective slots to form the pyramid shape. Be careful, though, and patient. Initially I was worried that I'd have to tape the edges together, but once I slowed down, I found that the tabs fit together neatly.

The Focus Pyramid comes with instructions that are easy to follow. For best results, you'll need a camera that offers AF micro-adjustments, a tripod, lenses and a flat surface on which to rest the Pyramid. A bubble level is recommended for the most accurate alignment of your camera. Once you're set up, follow the included directions to shoot a single image, examine it on your computer screen and then bracket using the recommended AF compensation settings to figure out the level of adjustment needed.

I've only just started testing the Focus Pyramid but, so far, it seems to work well. And the directions are really quite easy to follow.

Although the Pyramid can be disassembled to store flat, I'm a little concerned about the wear and tear on the tool. Even though the paper is relatively durable—and my origami skills are pretty decent—unfolding and refolding (and possibly bending) could throw the alignment slightly out of whack.

On the other hand, it's pretty small so I think I'll leave it set up for now, and just tuck it out of the way. Worse case scenario, the next time I get a new lens, it might be worth shelling out another $25 for a new one.