I read something in passing on the net, can’t recall all the details but it was something like if you have DSLR w/ auto focus and you were auto focused at certain focal length and then you turn off the camera, when you turn back on, the focus is messed up so you have to re-focus at infinity and then turn it back off and on, etc.etc I know have the details missing, but can anyone explain this? (I don’t yet have DSLR, just in the process of learning and shopping around for one). THANKS.
Caffeinated Content for WordPress
Comments
Caffeinated Content for WordPress
Hmmm…I havent heard about that on any camera that I have read about. That covers most of the major brands DSLR’s, like Canon, Nikon, Sony, Pentax, etc.
Sounds like it might have just been a particular lens on a particular camera. Sounds very rare. I have never encountered it and I have been shooting a couple of years using Canon and Pentax.
But I may be wrong. 
Caffeinated Content for WordPress
I have heard this about LENSES a lot; every brand has about 1 or 2 lenses that just don’t quite work on some cameras when auto-focusing from way far to way close or vice versa (it even is specific to certain focal lengths, like the review states). But this never happens for more than a couple lenses per camera (for cameras like the D40, which have limited lens sets, it doesn’t happen at all).
So this confuses me.
Caffeinated Content for WordPress
The only problems I have ever had with auofocus are usually associated with low light or low contrast situations.
Without clear objects to measure the sytem can get lost and hunt.
I haven’t heard of this problem and none of my DSLRs have had it.
However, if you turn off your camera, point it at something else, and turn it back on, the lens may well hunt around for proper focus.
V