New Pentax K-x focusing questions

[Cecilman]

Love my new camera and am somewhat new to photography. I love photographing wildlife birds especially and am having about 50/50 luck on images being as sharp as I would like, mainly getting body in focus, eye sometimes a little out. My question is about the several different focusing modes, 11 point , 5 point , center,is one better that the other for this type of photography? Any input is appreciated, Thanks Cecil.

[Mr Guy]

Depends on what you're talking about, really. Are you talking about birds in flight, birds in bushes, birds close up, birds far away, birds birds birds birds!

I bet you'll get better answers from people who are seriously into birding, but I can foresee several potential concerns. The knee jerk reaction is to say you're going to get your best AVERAGE shots from 11 point automatic. That'll give you the best odds of a good snapshot. However, I'm guessing from your description of the problem you're not really talking about a nature walk so much, as you are talking about some seriously close in zooms, and are trying for very tight depth of fields all National Geographic style.

Birds present all the difficulties of moving athletes and children, with the unhelpful traits of being generally fairly uniformly contrasted (arctic species being obvious exceptions) and surrounded by either blank sky or a tangle of branches and leaves. That gives a lot of room for error in an autofocus system to correctly guess where you want focus. My guess is that for really good shots, you're going to need to learn to prefocus manually, and possibly read up on using catch in focus.

You may also consider increasing your depth of field to give yourself more room for error if possible. I have a hunch you may be using a very fast shutter speed and a wide aperture to help with motion blur, but you may be restricting yourself beyond your abilities, currently.

[inkista]

I'm a Canon shooter who concentrates on birds in flight, so this may not work for you, but I tend to have the most luck/speed with single center-point AF and "one shot" mode. I know. Not typical. What gave me the most AF speed, though, as using a supertele prime with a ultrasonic focus motor and a focus limiting switch.

If your lens has a focus limit switch, use it. That will limit the distances the lens hunts through to lock focus, which will speed up AF performance. If you've got a teleconverter on the lens, try taking it off. TCs can seriously whack up your AF performance, particularly if you're using a slower lens and/or a zoom lens. Keep both eyes open to track your bird in the sky.

I can also recommend seeing if back-button autofocus functions may work better for you than the half-press-to-lock techniques (while that page is for Canons, it pretty much holds true for all the dSLRs out today, regardless of brand).

Also, don't forget that stopping down can give you more DoF to work with.

[Crossfire905]

I'm no expert, but I think perhaps you might be better off focusing manually for such shots and relying on your eyes more than the camera for focus, particularly when you might have some fairly wide variations in the depth of the scene, such as when photographing a bird in a tree. The camera might not even be able to find the proper focus at all; in other words, its "best guess" in AF mode might still be wrong.

If you decide to try focusing manually, keep in mind that the K-x has a menu option to enable an "in-focus" beep when it decides that the subject — based on your selected AF point(s) — is in focus. There is also a visual indicator, a small hexagon, on the bottom row of the viewfinder display to indicate proper focus according to the camera. Again, though, that's a guess on the camera's part, so use your eyes too, especially when your actual subject is not within one of the selected AF zones. The camera could be focusing on something else entirely.

Some shots just call for manual focus.