Autofocus in progressive mode.

M

monster

Well-known member
Why is it that the DVX100A does not have good autofocus in progressive? I know Panny calls it focus assist but what is the technical reason they can pust real autofocus on progressive shooting?
 
Re: Autofocus in progressive mode.

Because in progressive mode, the CCD is acquiring information at a much slower rate, so the focus mechanism only gets updated half as frequently (or less). The autofocus motor needs to receive feedback to know what it should do next, and when it's getting only 24 updates per second, it's a lot more difficult to adapt and adjust than when it's receiving 60 updates per second.

Panasonic didn't cheap out or get lazy, they implemented it the best they could. In the original DVX they thought people would be frustrated by the slow response time so they actually disabled all form of autofocus in progressive modes. But people wanted it, so in the 100A they added it, but they changed the name to "focus assist" so people wouldn't be expecting the same high performance that's possible when the CCD is running at 60 fields per second.
 
Re: Autofocus in progressive mode.

thanks Barry, so other cams like the GL2, XlL1/XL2 also have slow autofocus in progressive modes?
 
Re: Autofocus in progressive mode.

The GL2 and the XL1 don't have progressive, so no, they don't have slow focus.

As for the XL2, it remains to be seen, but I would strongly suspect that yes, it will have the same slow focus issue.
 
Re: Autofocus in progressive mode.

No progressive in the GL2 and XL1? Never used those cams but thought this was the reason people used them. I guess I thought frame movie mode was the same as progressive.
 
Re: Autofocus in progressive mode.

nope, frame movie mode was actually using a type of deinterlacing, so your actualy footage was lower resolution than in 60i mode.
 
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