Focus on Focus. A look at micro focus adjustments and the Lens Align Pro calibration system.
by Barry Howell: Have you ever found a menu option on your camera that made you wonder, “What’s this”? I found such an option on my Nikon D300 called “AF Fine Tune.” My old-school curiosity sent me on a quest to discover its purpose, and how it could improve image quality. With a few quick Google searches, I found multiple forums and discussions about the importance of calibrating lenses to your DSLR camera bodies.
A recurring theme on the ProPhotoShow.com podcasts, and in other various articles, is how to make your images have more impact. There is no bigger buzz kill for photographers than capturing an image we think will be great, only to find that it’s a little soft. There are many variables we can control to ensure optimal sharpness: shutter speed, depth of field, steadying the camera, etc., and I always assumed that if I focused on the right spot, my images would be tack sharp. Guess what? That isn’t always the case, and I was determined to overcome the problem.
Before contacting Michael Tapes at RawWorkflow, I performed a very un-scientific, but effective test of my AF Fine tune option. I was photographing the MN State Boys Hockey Tournament at the Excel Energy Center, a venue that is well lit for television broadcasts. I very carefully focused my Tamron 300 2.8 lens on some helmets lined up on the boards. The scene had great contrast, I was using a monopod, and I figured could get this image dead on. I zoomed in at 100x on the LCD and it looked pretty good. I then went into the menu and made a +5 adjustment, took another shot, and upon inspection realized I had made it worse. Then, I made a -5 adjustment and the image improved noticeably. I knew then and there that I had to calibrate my optics.
Within a week I’d found such a tool; I obtained a Lens Align Pro Focus Calibration System. I invited several photographer friends for a focus calibration party at my studio and we embarked on a journey to make our gear perform better. In our group were five Nikon shooters and one Canon shooter. Between us, we probably had over $50,000 worth of bodies and glass waiting for a checkup. The results were at times sobering, but every lens, once calibrated, focused better than ever before. The calibration method involves the following steps; it took a little trial and error, but they were pretty easy to do reliably.