biggles wrote:the picture was filmed at f10 and in video pro res
Bingo (probably)!
It's very possible you were seeing, at least in part, the normal and expected result of
diffraction caused by using an aperture setting too-small for the size sensor in your cam. This is not an issue specific to BMD cameras; it can happen with all cameras.
A "S16" size sensor as in the BMPCC pocket cam will record sharper-looking images if the aperture is set to f8 or probably less. Most lenses yield their sharpest results between approx. f4-f5.6, although this varies with different lenses. For example, some lenses are sharp all the way down to their wide-open aperture, but this is rare. Best to test your lenses with your cam to be sure.
Also, some filters, especially all-but-the-best variable ND type filters, will undesirably soften images, sometimes only at certain focal lengths. Again, carefully test your filter, lens, and camera to determine what combination yields best results.
Of course, opening the aperture to lower f-stop values when shooting a bright scene will often mean you'll need to adjust exposure in part by using an ND filter. As noted above, some ND filters are better quality than others, usually proportional to their cost. YMMV.
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