Why do some people use 1/30 or 1/60 ss instead of 1/50 or 1/125?

The way I learned it, if you shoot at 24fps, your shutter speed which is -not- equivalent to your frame rate should be double your frame rate or whatevers closest. So I shoot 24p at 1/50 and 60p at 1/125. I saw a pretty successful video director use 1/30 for 24p and 1/60 for 60p. He gets a stop more light than me and it makes me want to do the same.

So...what do you think?

Try it and see. It's your video, if you like it what's the odds?

My thoughts are that the images will appear softer as you are taking longer to expose each individual frame and thus the subject will have more time to blur within the image. Great if you are trying to convey a dreamy or speedy image or to generate greater contrast between a static subject and other things moving around it - the moving things will be blurred and the static thing crisp.

it's true, you get some extra light taking the shutter down from 1/50 to 1/30, but you will also get more motion blur on moving objects, which becomes more pronounced as you slow the shutter down further. 1/30 isn't a bad tradeoff for more light sometimes, especially for run-and-gun event work in dark corners, but if you're looking for natural motion blur, a shutter speed double the framerate is the accepted standard. as you probably have already figured out, shooting at faster shutter speeds will reduce motion blur, for a hyper-real look, which is used to effect all the time.

Double the shutter speed was a convention used in the day's of a mechanical shutter. In the digital age, it doesn't matter as much. The increase in motion blur is negligible. The other time it helps out is when you get flickr from LED or florescent lighting.

Well in that case why cant we go even lower than 30?

thedcmule2 wrote in post #14471666
Well in that case why cant we go even lower than 30?

Because your shutter speed needs to be fast enough for the camera to generate the number of frames per second that you're shooting at.

Very smart thanks guys