How to get only luma channel

[Jon Schnarr]

Is there any way to only process the luma channel on a T2i, before or when writing to the card?  I mean just the 4 in 4:2:2.  So, 1080p 24fps, black and white with no or little compression.

[chmee]

4:2:2 (and any other) subsampling is a picture-definition after demosaicing, thus it cant be done. or better: we dont know much/enough about the hardware-encoder inside the body.. honestly saying, most of compression-efficiency is realised by simplifying the chroma-channels

no, i highly doubt..

[Jon Schnarr]

Thanks.