4 replies to this topic

[Saxoben]

Hi all,

For the last few years I've been making underwater photographs, but now I'm switching to video.
Throughout the years I found out that one of the most important things is to know the equipment your working with. So after buying a Canon HF G10 last week (still not sure about the housing to get) I'm reading my way through the Instruction manual. There I read about shutter speeds.
I know about a shutter and shutter speeds on a photo camera, but on a video camera??? I don't think there really is a shutter inside a video camera, or is there?
So I can't think of how this works on a video camera. Does anybody know?
And if you choose a slow shutter speed ( <1/50 ) and you shooting with a frame rate of 50fps I guess there will be blank/black frames......??

I'm confused....

Thanks,
Ben

[SimonSpear]

Hi Ben

For 24p or 25p set your shutter to 1/50 and for 30p set to 1/60. Hope this helps.

Cheers, Simon

[Nick Hope]

The choice of shutter speed is a trade off. Faster shutter speeds give you more sharpness in each frame and an overall "sharper" picture. Slower shutter speeds give you more motion blur. Fast shutter speeds can give a "stacatto" effect to the motion, particularly at 24/25/30p, a bit like a flip-book. Slower shutter speeds can make the picture soft, and if you set a speed slower than the framerate you'll get a weird strobey effect (not black frames).

The figures Simon refers to are equivalent to a shutter angle of 180 degrees. i.e. the shutter is open for half the time. In most cases this is a good compromise between sharpness and smoothness, and most video cameras will default to this.

If there is little or no motion then you have more flexibility with shutter speeds. You might want to choose a faster shutter speed if you have too much light, no access to ND filters, and want to avoid a very small iris, or your iris is already minimised. Alternatively you might want to choose a slower shutter speed to get more light in and avoid very high noise-inducing gain (tripod-mounted shot at night).

If you are planning to do any slow motion using motion estimation (optical flow, Twixtor, MVtools etc.) then faster shutter speeds are better because the software can interpolate sharp frames more easily.

A question for those with 60p cameras: Does the shutter default to 1/60 or 1/120?

[Saxoben]

Thanks Simon and Nick.

Nick, you should write a book about underwater videography, or give workshops. Very clear explanation about shutter speeds. My confusion is gone.

Thanks again,
Ben

[A.Y.]

A question for those with 60p cameras: Does the shutter default to 1/60 or 1/120?

For 1080 60p, my NEX-5N default to 1/60 under low-light situations so the NEX camcorders should be able to do the same. The great thing about 60p is that fast shutter speeds can be used and the footage will still come out smooth and video frames sharp as can be.