A screen grab will never be as good quality as a photo taken in camera mode. But if you don't care too much about image quality it is an easy way to do it.
File sizes (depending on various shooting conditions like light, subject, movement etc.) are around:
- 5MB - JPG
- 25MB - DNG
- 10MB - Screengrab
So even if screengrabs are lower quality, they are much bigger in file size than JPG's.
Remember, FILE SIZE, is not equal to PIXEL SIZE.
I pull stills from QuickTime. Do any of you know what the equivalent shot I get this way versus taking a still? In other words, how many megapixels does it equal.
You get the same amount of pixels as the video setting shows. But of a lower quality than the camera produces. PS: remember screengrabs are blurred if there's movement in the subject or camera, so ideally take a grab from a calm scene with the camera steady.