Sunday, December 9, 2007

How to test your K10D for focus error

I took some photos at our companies holiday party last week and found that 50% of them were not focused properly. This led me to doing some research on the problem to see if it was my fault or the cameras. Since 50% were problematic I assumed it was my error and not the camera.

First things first. Download this document by Tim Jackson at

Follow the procedure in the PDF file. Don't worry that it says D70 all over the place, this test works on any camera.

Now from doing this test and getting the results as indicated in the photo above, the focus problems I was having at the Holiday Party were not caused by ~6mm of front focus. So I am having another problem. I'm assuming it was due to the dim lighting in the room. Several times the internal flash had to strobe for focus assist. I'll need to keep an eye on this for future portrait sessions.

There used to be a way (and if you have firmware version 1.10 installed there still is) to go into debug mode and adjust the focus. However, if you have upgraded your firmware then it will not work as the key press sequence to get into debug mode has changed. If any one knows the new key sequence please email me.

Here is the post to get into debug mode with the latest firmware.


Anonymous said...

In my experience, the vast majority of focus errors are introduced by the camera's multiple focus points. If you haven't already, set the camera to use ONLY the center focus point. To shoot, focus on whatever you want to be in focus in the shot, then compose, then shoot. Can't say I'm an expert, but I've seen lots of folks blow good shots by letting the camera choose the focus point.

Photography Rulez said...

Yes this is true, but in my case I most always use the center focus point by itself. I'm a control freak that way. Maybe that's why I like the K10D so much.