CX7 focus problem

[Skwrl 56]

Hi all,

I've been spot focusing my CX7 prior to wingsuit jumps, but finding that the camera is going slowly increasingly out of focus as the jump progresses. (In other words, the picture starts as sharp and then gets blurry the longer into the dive you go.) I have it mounted in a Tonfly, so there's not much (if anything) exposed. Thoughts/suggestions?

Skwrl Productions - Wingsuit Photography

Northeast Bird School - Chief Logistics Guy and Video Dork

[DSE 5]

Spot focusing on what?
It's *possible* that air pressure is moving the element, but highly unlikely.
You're sure you're leaving it in Spot mode and not merely exiting that dialog?

[Skwrl 56]

I'm spot focusing on an object typically 5 feet away; my understanding (I am a camera dummy) is that that's what I should be spot focusing on. Is that right?

I can imagine that I would have screwed up exiting that dialogue wrong once, but I can't imagine that I'm doing it repeatedly. Dunno.

Skwrl Productions - Wingsuit Photography

Northeast Bird School - Chief Logistics Guy and Video Dork

[DSE 5]

If you're spot focusing on something 5 feet away in one lighting condition, and then jumping, it's entirely likely that this is the problem. My spot focus is approx 10' back, and whenever possible I use a focus chart. When not possible, I find something black/white.,
It shouldn't be "losing focus" but rather not be focused. In other words, the depth of the focal point shouldn't change no matter what.
Part of it, of course, is that you suck in PR. All of you.

[PharmerPhil 0]

This is the way I usually focus on an HC-5. I pick a spot on the plane 6-7 feet away (for tandems), and lock focus on that spot using the spot focus touch screen shortly before exit (I put this button on the first page of my custom menus). I use auto focus on the plane before that, and then I go back to auto focus after I land. I've never had my HC-5 or A1U drift doing it this way. Changing light shouldn't change the focus point, but it could change your depth of field somewhat.

Are you sure you are setting the focus correctly before exiting the spot focus menu? Are you sure you are picking a good distance for the type of jumping/videoing you are doing? Are you sure your "blurriness" is a focus issue? If yes to all, I would suspect the camera, but that sounds bizarre.

[TomOwen 0]

I am jumping a CX7 with a Royal 0.5x lens.

The ONLY way I'm getting the damn thing to focus is to set it to manual, 0.1m (or whatever the closest setting is). Still seems to focus correctly on stuff at any distance like that.

[DSE 5]

Spot focusing works fine with a low resolution lens too, find something that is black/white. Be sure you have no zoom in the mix.