I have a 700D with 5,184 horizontal pixels but HD video has 1,920 horizontal pixels. That's a difference of a factor of 2.7. So my question is when used in HD (1080p) mode (1920x1080 pixels) does the canon processor use 2 pixels sometime and 3 pixels other times to 'create' each video pixel i.e. add their contents OR does it just sample 1920 of the 5184 pixels according to some 'table' Canon built into the DIGIC processor? This is important as if it is the former then more light is being collected and I am using HD video in astronomy, where there is never enough light! Thanks! David Moore, Editor Astronomy Ireland magazine
