[RichyX]

I just read the article posted here: https://www.pentaxforums.com/forums/pentax-dslr-articles/51036-how-use-trap-f...tch-focus.html

It says:

With Pentax K20D, you can use not only the central AF point, but every one, allowing for a better placement of subject in the frame of the picture.

How can this be acheived?

I can only get my K20D to use the center focus point with my A50 f/1.4.
Body set to AF-S and catch in focus turned on.

---

Last edited by RichyX; 11-07-2009 at 12:40 PM. Reason: Because I'm an eejit

[rockmaster1964]

The A50 1.4 will only do center focus point. It is not a autofocus lens. Also you want the camera set to AF-S not AF-C.

[RichyX]

The A50 1.4 will only do center focus point. It is not a autofocus lens. Also you want the camera set to AF-S not AF-C.

So the person who wrote the article was talking rubbish?

[rockmaster1964]

Only the auto focus lens will do non center focus point. To do focus trap you always have to use AF-S. The article states that it must be in AF-S. The article also is taking about a auto focus lens.

With a manual lens if you have the camera in AF-S and hold the shutter button down. It will take a picture once if gets focus confirmation. The shutter will always fire with AF-C and AF-M whether it is in focus or not.

[Canada_Rockies]

If you select the focus point on the k20 you can trap at that focus point, I believe. Unfortunately, the k10 will only use the original snap-in-focus, which works only with manual focus lenses. The first thing off the wall I tried with the DA* 50-135 was to set the lens to MF and the body to AF.S. No joy. The whole camera went into manual focus.

So, here is what you need

• A manual lens for any Pentax AF camera, film or digital
• With the k20, an AF lens with its switch in MF will also work
• Set the camera to AF.S (single - only fire the shutter when focus is obtained)
• The camera will now only take an image when the focus indicator (green hexagon) lights up.