[Mortox]

never done this - any advice on how to do so?

thanks.

[traderdrew]

I have heard of sending a lens back for recalibration. I am more careful with my lenses than I used to be. I wrap my big lens in a towel when I travel, foam would probably be better. Lenses are precision instruments and you dont want bumps to cause subluxations.

[HawaiianOnline]

If you're talking about calibrating the autofocus system for each lens, the procedure is covered in the manual. You can use an autofocus test chart like Jeffrey Freidl's Test Chart.

[RonHendriks1966]

There are several ways to do the job.

What I did was making a series of shots, -10 -5 0 5 10, and look where the focus is the sharpest. Then take a closer look at the range where it was, like: -7 -6 -5 -4 -3 to make it precise. See at it that your camera starts focussing each time from scratch bij adjusting it. Then at the end take some pictures of the two remaining possibillitys like: -5 or -4 to be sure it wasn't just an error or focusaverageing at a point.

With my K-7 I used:
http://focustestchart.com/focus21.pdf

Now for my K-5 I bought Spyder LensCal


This makes it easier to get it excactly right at the 45 degrees angle.

Also check some more distances and diafragma's. Sometimes it is just a little compromise. I mainly use primes, so not to many experience for zoom. I only have the 50-135, and that was tacksharp on the K-7, not yet used on my K-5.

[inferno10]

I use the LensAlign MkII for my calibration. Here's the creator giving a demo of how it's done:

You Tube

You Tube

- Jason