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-   -   GS400 test pattern results - frame vs interlaced (https://www.dvinfo.net/forum/panasonic-dv-mx-gs-series-assistant/32183-gs400-test-pattern-results-frame-vs-interlaced.html)

Rokta Bija September 19th, 2004 07:08 PM

GS400 test pattern results - frame vs interlaced
 
Seeing the DVC30 thread about 50% loss in frame mode, I thought I'd do a test with the GS400 comparing interlaced to frame.

Test conditions were not great, hand held, indoors, auto focus, low light.

Despite that the most striking thing was that frame mode displayed just as good of vertical line resolution as interlaced. Horizontal res is very crisp. In fact most of the frames looked slightly better in frame mode than interlaced, but that could have been my shaky hand.

I would like to see someone else verify this. I am skeptical about the results, but I double checked the each clip on the timeline to make sure one was interlaced and one was progressive. They were.

http://users.adelphia.net/~jp1/normal.jpg

http://users.adelphia.net/~jp1/frame.jpg

Boyd Ostroff September 19th, 2004 09:11 PM

The vertical resolution in the frame mode chart looks like what you would expect from normal 60i video, around 360 lines. So it doesn't seem to be doing field doubling. But it probably isn't doing real progressive scan either, or we would see higher resolution than that....

Guy Bruner September 19th, 2004 09:45 PM

Yes, that is consistent with my tests. There is no discernable difference between interlaced and frame mode.

Rokta Bija September 19th, 2004 11:24 PM

It is strange though that the DVC30 does show some loss, about what you would expect if Panasonic is still doing same green line pixel shifting described in that article they wrote. (linked to elsewhere on this forum)

Maybe the extra pixels in the 400's CCD's would explain some of it, but I don't see any loss at all, they look indentical.

Makes you wonder if they are doing frame mode differently now, like just combining the two fields without pixel shifting.

Alvin Tan September 19th, 2004 11:34 PM

Oh, do most people use frame mode or interlaced mode? Sorry I'm new at this. What's the advantage and if I intend to create DVD later, which mode should I be using? Thanks.

Boyd Ostroff September 20th, 2004 06:22 AM

I suppose the GS400 might be doing some sort of deinterlacing in firmware, like we might do with software in post? Looking at some frames with motion in them might give a clue to this....

Mikhail Transact September 20th, 2004 01:28 PM

I've get similar results for PAL GS400
normal
frame

Bruce Simpson September 20th, 2004 08:05 PM

<<<-- Originally posted by Alvin Tan : Oh, do most people use frame mode or interlaced mode? Sorry I'm new at this. What's the advantage and if I intend to create DVD later, which mode should I be using? Thanks. -->>>

I use interlace mode for most work but when I'm filming fast-action footage with a fast shutter speed I use frame mode so that I can grab single images if I want to. The reason I use a fast shutter is to freeze the motion in each individual frame. It's much easier to get just the right action still this way -- rather than trying to hit the shutter at exactly the right moment in card-mode.

If you use interlace mode with high shutter speeds the results are not pretty when examined on a frame-by-frame basis in the face of rapid movement :-)


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