Justin Jackson wrote:Rick, that is interesting. I thought Q5, due to the nature of sports having a lot of motion, would end up with more data, larger files, etc.
Consider the following:
a Long GOP format Finter Frame compression) that shoots a stationary frame from a tripod can take advantage of fact that each frame in a long sequence is more or less the same as the previous one, or the next one. This format optimises file size by taking change over time into account, so if there is little change, files become smaller.
An Intra Frame compression like Braw or ProRes, that stores individual frames, is not influenced by motion in preceding or succeeding frames. This is great for 'motion stability' when shooting moving water or foliage that moves in wind, for example. Since all compression takes place 'inside' the frame, the question becomes: how much fine detail does the frame hold that needs encoding?
Filming sports in an intra frame codec like Braw with a filmic shutter speed will give you frames with a fair amount of motion blur, which in turn will result in easily compressed frames.