Does a digital zoom available on movie mode?
 

Can anybody explain digital zoom on the movie mode ?
This is very important to me to decide whether to buy the camera or not!

On picture mode a digital zoom is probably a crop and then a resize of the processed (or maybe the pre-processed picture) , so instead of getting a 12M picture you get 6M or 3M resized.

But what about applying digital zoom on the motion picture mode ?

Remember that (read the specs) there are 10.5M pixels available for the 16:9 video,
to output about 1M pixels of video at 720p.

Does it mean...
1. Using only the center part of the sensor, like 5.25M pixels available...
2. Cropping each frame before processing ,still 5.25M pixels available.
3. Cropping the processed matterial. (doesn't make sense , because will require alot off proccesing power).

Or somthing else ?

I would have thought the camera would "bin" the pixels, so your 12MP (or 10.5MP) still image sensor becomes a 2.1MP sensor by combining pixels thus effectively creating larger pixels.

No?

As far as I know, "digital zoom" isn't zoom at all - it's just cropping the picture and stretching it.

As far as I can tell, you can't record in 720p for example and digital zoom by using more of the sensor - I think that the 720p mode uses the entire sensor but take larger averages when trying to decide what color to make a particular picture.

If you want that kind of effect, it's possible simply to record at 1080p, then in post, render to 720p, and create the crop then.

Very good question. I think this is near to impossible to answer without a direct statement from the manufacturer. The 5D II as a real issue with aliasing and that seems to be based on discarding pixels rather than "bining" them.

I have seen a bit of that aliasing in the GH1 footage as well, but it could also be the lousy codec or post processing.

Btw: is digital zoom available in movies? I found some indication in the specs ages ago but noone actually confirmed.

No. Binning only works in monochrome, or a three-chip system. You can't do binning on a Bayer pattern sensor.

Yes 2x and 4x digital zoom is available in movie recording. They both result in significant losses of resolution and are therefore of questionable value.