From time to time I see questions about shutter actuations on this site and this got me thinking — does every frame of video count as an actuation?
Does this means a 10 minute video is "worth" 18000 actuations (10minutes*30fps)? And then what about live view?
Obviously, I'm talking only about cameras with a mechanical shutter. My camera is a Canon 550D but I assume this will be the same for every camera make and model.
No, for a CMOS based dSLR, the shutter remains open during the video recording, so the shutter in use is actually electronic. B&H photo, by the way, have a pretty good article on some of the concepts. It's in reference to video recorders, but much, not all, of it applies to dSLRs as well.
Anyways, you do have an actuation for the act of flipping the mirror and opening the real shutter, but after that it's just sensor activity. A far cry from the 18,000 otherwise. :)
Video uses an electronic shutter, rather than the physical shutter used for photo taking, so each individual frame doesn't contribute to the actuation count in a DSLR.
However, the mirror and shutter must open at the beginning of live view mode, and close at the end, so technically there is one actuation per time you enter live view.
does every frame of video count as an actuation?
Only if you create the video by taking individual photos for each frame. As @Joanne C has already pointed out, the shutter stays open when the camera records video, so only one shutter actuation for the whole video.
However, people sometimes make time-lapse videos by taking a sequence of photos at regular intervals, often using an intervalometer to control the camera, and then compiling the photos into a video. In such cases, then yes, a shutter actuation is required for each and every frame.
