Since the advent of good quality 4k video I have found that I use the still camera less and less - careful selection of a frame from a video seems (to me) to produce results that are technically as good, particularly as they are going to be viewed on a screen of fairly low resolution. This is particularly so in the case of images of sexual activity. Posed stills always seem to look like, well, posed stills, mainly because the models have to remain still and that requires them to be in a balanced possition. Reality is much more to do with movement with bodies moving through positions that would be impossible to hold (as gravity would intervene). The same seems to apply to facial expressions. The expression on a persons face during passion is transitory.
With video you can select a frame with just the right body position and facial expression.
Comments?