View Full Version : When to disable the 'Shutter'?


James Kuhn
July 18th, 2013, 12:29 PM
Being new to 'video' (though, Stills background), could someone please explain "why and when" it's appropriate to turn the 'Shutter On or Off'? As I understand it, when a video camera 'Shutter' is disabled, the 'Shutter-Speed' reverts to the 'Frame-Rate'? For example, if you're shooting 30 fps (29.97 fps) the 'effective Shutter-Speed' is ~1/30th.

Please feel free to correct me, I'm a little shaky on the 'facts'.

Thanks,

J.

Brian Drysdale
July 18th, 2013, 02:17 PM
The shutter isn't required when shooting interlace video, but when shooting progressive you get a smearing on action when the shutter is switched off. One reason for not using the shutter is obtaining exposure low light levels, however, this has tempered by the "ghosting" effect on the action.

For a normal use the optimum shutter speed is usually about temporally half that of the frame rate e.g 1/60 for 30 fps.

James Kuhn
July 18th, 2013, 07:15 PM
Thanks Brian!

I shoot primarily in 'progressive', so, I haven't had the need to turn-off the 'shutter'. I understand the issue of ghosting when 'dragging the shutter', i.e., 'motion-blur'.

So, it's primarily a 'progress/interlace thing'? Are there any 'creative' reasons to 'not use shutter', beyond 'motion-blur'?

I appreciate your insight.

Regards,

J.

Brian Drysdale
July 19th, 2013, 01:19 AM
Apart from the blurring, there's no creative reason other than wanting the extra DOF because you usually gain a stop when not using the shutter, although these days the problem is often trying to ND the sensitive sensors.

It's worth doing a test to see the effect.

James Kuhn
July 19th, 2013, 08:43 AM
Brian...again, thank you for the thoughtful response. I'm all about 'testing', but did not understand the practical use for disabling the Shutter.

Regards,

J.