K20D AF Adjustment

I have had one or two problems with AF (intermittent), mainly with wide apertures (ie F2.8 or wider) where the AF of the K20D is out. It mainly focuses on an area behind the point I want to focus on.
Now I have found this AF adjustment in the menus of the K20D.
Has anyone used it? What are the best ways to use it, and is it subject to individual lenses? (I have noticed is will do one shot or ALL in the settings, whatever that means)

Advices please.

Have a look here link

It will memorise the settings for up to 20 Pentax AF lenses (and possibly also A lenses). Enough for most people, but not Clarky!

I think we almost all use it; it's well worthwhile because some lenses are way out.

With a little trial and error you'll soon get the hang of it.

G

Thanks for this, Now I just need the printed chart to sort.

Oh. BTW can this be done on the K10D? As it does not have this setting in the Menu.

Try here link for the K10

You are making a joke there.........right ?

Hey, I only needed to adjust one of my lenses, FA 50mm 1.4, so leave me alone

No, Just being stupid!

G

Actually, if you tend to rely on the focus indicator when using manual focus then this could have some merit !

I am not a fan of using these focus test charts where the camera is focussing on a target that is at an angle to the focus plane. I am never confident just where the camera actually focussed.

Instead, with a camera that offers a live view function, I have used the technique that relies on moire interference patterns between an LCD screen and the live view screen. The advantage of this approach is that the camera is focussing on a target that is at right angles to the camera. Thus you know exactly where the camera is attempting to focus.

The following web site describes one way of doing this (it's for a Canon, but the principles will apply to a Pentax K20D):

http://www.northlight-images.co.uk/article_pages/cameras/1ds3_af_micoadjustment....

I note in this article that Canon recommend making any adjustments at the long end of the zoom range..

Are there any other views/suggestions about correcting zoom lens focus errors?

Zoom lenses may not have an accurate point of focus anyway. Most modern zooms are parfocals, where after zooming the focus point will change.

So the old advice of focusing at the long end and then zooming out is not very good.

Zooms are such a compromise that it would be difficult to now where to start really - I leave well alone and they work well enough.