GH3 ETC area, GH3 vs GH2

[dop16mm]

All else being equal, if the GH3 sensor is slightly smaller, and not true multi-aspect, would the ETC area be smaller than on the GH2? It is already smaller than 16mm, closer to 1/2" in video sensor terms, so being even slightly smaller could make a difference for users of 16mm and c-mount lenses.

Could be wrong as I thought the official posted crop was 2.6 in 1080p on the GH2 and they are listing 2.4 for the GH3, scaling from a smaller number of total 16/9 pixels.

 

[Barry_Green]

Interesting question. I would think it'll be a little smaller, yes, because the ETC mode is based on a discrete 1920-pixel-wide swath of the sensor. The GH3's sensor is slightly higher resolution, and slightly narrower, meaning the pixels are slightly smaller, and therefore 1920 of them will take up less physical space than 1920 GH2 pixels. That doesn't explain the 2.6 vs. 2.4 though.

 

[mpgxsvcd]

Interesting question. I would think it'll be a little smaller, yes, because the ETC mode is based on a discrete 1920-pixel-wide swath of the sensor. The GH3's sensor is slightly higher resolution, and slightly narrower, meaning the pixels are slightly smaller, and therefore 1920 of them will take up less physical space than 1920 GH2 pixels. That doesn't explain the 2.6 vs. 2.4 though.

Actually both cameras have the same sized sensor in 4:3 mode and the same number of pixels. However, the lack of multi aspect ratio changes the field of view of the 16:9 non-ETC video mode to be higher than the 2x crop factor.

Therefore, when you use the GH3 ETC zoom it will give you the exact same field of view as the ETC mode on the GH2 does. However, that also means that the absolute magnification difference is less because the GH3 16:9 non-ETC mode has a smaller field of view than the GH2 does.

If my math is correct then the GH3’s crop factor in non-ETC 16:9 video mode is actually 2.1668x and it is still the same as the GH2 in 16:9 ETC mode. It is actually 2.160x to be more accurate.