lenses | Photocrati

Q and A: How does the Autofocus Adjustment function work–and should I use it?

Question

From reading reviews, I know that some recent DSLRs, like my Pentax K-7, include an Autofocus Adjustment function that allows for modifying the AF system for more accurate focus with certain lenses. Is this function necessary? If so, how does it work? R. Webber

Answer

Yes, an increasing number of high-end DSLRs of several brands include a feature of this type. It allows for instructing the camera to focus slightly more closely, or to a slightly greater distance, than it would do at default. This function would be useful for an older AF lens-especially one that has been banged around-if it is no longer focusing accurately. You may find that it focuses slightly ahead of the subject, or slightly behind it; these issues are called “front focus” and “back focus” and they call for AF Adjustment.

Before using this in-camera feature however, be absolutely certain of the lens’s exact focusing tendencies. (more…)

PMA 2009: Great New Photo Equipment

Peter Burian reports on the best of the new gear at the Photo Marketing Association’s extravaganza in sunny Las Vegas, Nevada

The largest annual photographic trade show in the world, PMA 2009 was held in Las Vegas, Nevada in March. While touring the show floor and meeting with exhibitors, it quickly became clear that many were aggressively developing their line of cameras. As usual, a vast range of compact models were announced, many with HD video modes and more “intelligent” automation than in the past. I found fewer digital SLR models than expected, but two companies showed interchangeable lens cameras without a reflex mirror and these are just as versatile. In this report, I’ll briefly cover the most significant cameras (including two DSLRs announced shortly after the PMA event) and lenses as well as the most significant new printers.

Held in Las Vegas earlier this spring, the Photo Marketing Association's annual trade show attracted numerous retailers who wanted to check out the latest equipment.

(more…)