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View Full Version : Zooming on the sensor



andrzejkra
06-26-2009, 12:44 PM
Has anyone done some controled tests with the in camera digital zoom? I have some c mount lenses that might vignette and I'm thinking about using them for low light if I can live with a crop. It should look better to do it in-camera since it will upsample before applying compression. A good setup would be to film the same subject at full sensor, then 2x, and then 4x crop, each time doubling the distance from camera to subject in order to have similar composition for comparison. It would be interesting to see how the three shots stack up.

gmoe
06-26-2009, 01:02 PM
would be nice to have panasonic have a 1.5x crop feature as a firmware update though instead of just 2x-- heard good things about it on G1 so I can only assume that GH1 should be good as well but I will test this too when I get my camera..

PappasArts
06-26-2009, 01:06 PM
I haven't seen much about the new sensor crop feature on the GH1. Kohil posted some tests with it and the 2x mode looked very usable. My understanding is that it isn't a zoom-crop like most digital zooms, but it actually uses a smaller part of the sensor to output the video and scales it to the proper resolution before compression.

Since the GH1 sensor is much higher resolution than HD, it seems to me like this crop can be done while still maintaining nearly full quality, as long as the area of the sensor used to capture has 1080 or 720 horizontal pixels. Granted, the full sensor will still catch more detail becuase it is downscaling, but it seems to me that a 2x sensor crop should still have enough resolution to produce a very nice HD image.

Has anyone done some controled tests with this feature? A good setup would be to film the same subject at full sensor, then 2x, and then 4x crop, each time doubling the distance from camera to subject in order to have similar composition for comparison. It would be interesting to see how the three shots stack up. I was planning on doing this test myself, but I still don't have my camera.


I can't wait to try this feature out on some telescope shooting!

.

Barry_Green
06-26-2009, 03:02 PM
The GH1 has two modes, either an "enhanced optical zoom" which appears to be what you're describing, a sensor crop... and also a 2x and 4x "digital zoom" which appears to be an actual digital resize.

The "enhanced optical" would be sweet, especially for using with smaller-format lenses like c-mount -- except it doesn't work in movie recording mode! Only the "digital zoom" works with movie recording.

Ben_B
06-26-2009, 03:15 PM
Thanks for the post Barry...I guess we have another thing on list of wants for a firmware update.

andrzejkra
06-26-2009, 03:20 PM
The GH1 has two modes, either an "enhanced optical zoom" which appears to be what you're describing, a sensor crop... and also a 2x and 4x "digital zoom" which appears to be an actual digital resize.

The "enhanced optical" would be sweet, especially for using with smaller-format lenses like c-mount -- except it doesn't work in movie recording mode! Only the "digital zoom" works with movie recording.

Ah damn, I'll edit my post to avoid confusion. Must've got mixed up.