Shutterspeed vs fps

D

dwcdv

Active member
I try to understand this, but somewhere I get stuck.
On my HVX 200, in low light, I can reduce the shutterspeed to (lowest setting) 1/12 sec.
That means, I can expose 12 frames in 1 sec. max.
How can the camera run at 30 frames per second then?
Thinking back, I had a Sony PD 150.
The lowest shutterspeed was 1/4 sec. And as far as I recall, the Sony recorded 30 frames per second.

If it would lower the fps then I would understand... but there is no visible timelapse effect.

Somebody could explain that to me please.

Dorian
 
You are correct, 1/12 results in no more than 12 frames being exposed. The camera will still record 30fps, but it will only image 12, so frames will be duplicated.
 
Thank you Barry.
If I would expose 1/4 shutterspeed (like on the PD 150) it will duplicate x 6?
I am asking, because I want to get the something like the motion blur I archived, on the RED. But when I reduce the shutter speed, I need to reduce the fps as well and that does not give a nice smooth motion blur.

Dorian
 
Yes. It is impossible to have a shutter speed that's longer than the frame rate. The camera has to "hold" the frame in place long enough for the full exposure to occur. So that means that frames need to be duplicated. You cannot have more than 2 frames per second, when your shutter speed is 1/2 second. You cannot have more than 6 frames per second when your shutter speed is 1/6, etc.
 
Yes Barry, that I was thinking all along.
But there must be an other way, I remember, I saw ademo video of the AAton Minima, and it showed some motion blur.
But smooth movements.
At that time I was not interested in it.....
Now if you want to shoot a dancer with blurry motion, how could you do that?

Dorian
 
Motion blur comes from a long exposure time. Set the shutter at 1/24 in 24p, you'll get the blurriest smooth motion you can get.
 
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