DVX100 Focus Issues??

[heisest]

I just got the .6 wide angle from century in the mail and tried it out. It appeared that the focus was really "soft" (out of focus) on subject far away but if I were to look at things that are 1-5 feet away it looked crisp and clear. Then I took the wide angle off and looked at things far away and it looked kinds "soft" as well (but not as obvious). The switch was on auto focus (as well as the menu was set to that). And when I zoomed in I could see that the subjects far away were out of focus as I got closer but when I zoomed in all the way the camera suddenly was in focus. But if I zoomed out again it started to get out of focus and looked "soft" again when it was all the way out. Any ideas as to what is going on??

[Jan_Crittenden]

Sounds like you should have it checked by a service center.

Good Luck,

Jan

[heisest]

Sounds like you should have it checked by a service center.
Thought you might say that... :) :-/

[miltlee]

So I actually have a focus question that happened yesterday. I was shooting - using F5 scene setting yesterday. I have the dvx100a, and I had the camera in auto focus, but it didn't seem to be following focus. Admittedly, the subject was running towards me, and he was a young boy, it wasn't very bright out. But...having said all that, I wondered it there was an issue with using F5 or F6 and focus? I went to manual, and it worked just fine, but is it because of the lag in the LCD screen that I didn't think it was following focus?

Thanks for the help!
Milt Lee

[Barry_Green]

What you encountered is exactly what will happen. In progressive modes the focus system runs slower. In low light conditions it really has a tough time keeping up. You basically pushed it way past its capabilities.

There are reasons Panasonic deleted autofocus from the original DVX100 -- they didn't want people thinking it was "broken", is my guess. It's not. It's doing the best it can, but the nature of shooting 24fps instead of 60 means that it just can't perform as well. The XL2 suffers the same limitation.

[XCheck]

Barry, I am curious why is that?

I am just guessing that it must have something to do with the CCD having a signal pretty much all the time in interlaced mode (the half-frames), whereas in 24P, it has signal only half the time but the autofocus must process the whole frame?

[Barry_Green]

The CCD runs at 24hz in 24P mode, and it runs at 60hz in 60i mode. It gets information about 2.5 times as often, and that more-frequent feedback lets it respond much quicker.

In 24P mode, the CCD actually slows down to 24 times per second, as opposed to interlace where it's generating a new frame (and feeding new information to the autofocus system) sixty times a second. More feedback = more responsiveness.

And low light makes it much harder for the autofocus system to work... it needs bright light, high contrast on vertical lines, and quick updates to do its job best. If you want to see the autofocus system choke on focusing, point it at a white wall in a darkish room and put it in 24P mode with the slow shutter on. It'll take something like 2 minutes to lock down what it thinks the right focal plane is.

[heisest]

I tried my camera again last night and found out what the problem was! It focused just fine last night and the only difference between them was that the night I was having problems was when we were setting up our Christmas tree and I was shooting what was going on. I read recently (somewhere... could be on this forum) that the DVX100 has problems focusing on bright lights. I'm guessing my blinking Christmas lights was throwing the focus off. *::)