This question has probably been asked before, but could not find it. With the possibility of recording RAW video on a DSLR, file size matters because CF cards are limited. File size can be reduced by recording at 720p as opposed to 1080p. First of all, how do I compute the size needed for a certain resolution? I presume it would be > file_size_per_second = height x width x 14 x fpsand the result must be divided by some compression factor, I guess, otherwise the number would be too large. Now, the second question is: for practical purposes, how does the size of the screen need to be be in order to be able to notice differences between 1080p and 720p? Or, perhaps, does it also depend on what is being recorded? I'm asking this question, because I would go for 720p to save some space if it did not affect video quality significantly.
If you do 720 you are making compromises to the image quality. The whole idea of RAW video / Log is not to Compromise. Use an external recorder like an Atomos and get the larger image.
