Now the question is, is it worth the trouble supporting raw in this mode? The quality isn't too great, but slightly better than the jpeg.
Normal raw resolution is 4416 x 3296, "low light" raw is 2208 x 1664. The buffer's length is 1664 lines, but the actual image is somewhat shorter. The small sized raw has the same bit depth and CFA pattern as the normal one.
It sounds like they're adding or averaging adjacent pixels together to create the low res raw buffer.
It seems like you could do a similar thing on the hi-res raw buffer with any camera. I wonder if there's a difference in quality if you take a full sized raw file and reduce it to the same size as the low light raw file, using pixel averaging for the reduction. In other words, can you create a low light raw file by reducing a normal raw file?
I certainly wouldn't say it's urgent to supprot, but if it's not too hard it could be added as a port-optional feature.
New CCDs support this readout mode in hardware, this quarter resolution raw may be specific to them. It's not only a "more sensitive" mode, but is also faster to read out due to the significantly less image data.That said, I'm not really satisfied with the image quality. I tried to override the ISO sensitivity (default is 3200), but I still got horrible grain at (supposedly) ISO 80.
So it sounds like their goal is to increase the shutter speed, not improve the image quality. That's why it's probably stuck at 3200 ISO too. It looks like it wouldn't be useful to save raw files in this mode. A raw file of a poor image is still a poor image.
That would require some core changes - there's only room for one RAW (x,y) size at the moment. And it only makes sense if there's a camera that can produce usable quality in that mode.
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