I just read an article that I thought was interesting enough to pass along, assuming at least some of you have SLRs! =)

Seems like I recently heard some pro photographers saying that they send their lenses in every year for re-calibration. My MarkIII has a built in calibration tool that I can use to make minor adjustments to each/any lens individually, but I’ve never really had to use it so far. Even on lenses I’ve had for years. Maybe buying “L” (professional) lenses is the difference, but we do have a couple of plain ol’ EF lenses that have never given us any trouble so far.

Anyway, when I saw this focus test article, I was pleased to have a good way to actually scientifically test each one just to be sure. If you use it and find it helpful, I’d be interested in hearing about it! I plan to test mine as soon as I have an hour to take my time and go through all of my lenses and camera bodies. Should be fun! I like that kind of thing.

Here’s what the target looks like:

And that’s the setup.

And here are the results (or what *should* be the results if your lens is in focus). If your lens is out of focus, you’ll get something more like this…

…in which case it’s time to send it back for adjustments!

(Oh, for the record, all of these photos came from http://photo.net/learn/focustest, not my lenses, thankfully! =)