Lighting for 24p vs. 60p

Never realized that (having about 10 minutes of 60P shooting total in my life). Obviously raising the Shutter to 1/125 for 180 degree shutter would have an effect. Is that it, or does the frame rate itself have an effect?
 
Depends on the shutter speed. If you're shooting 60p at 1/60, which is typical, you're exposing all the time, so you don't need as much light as you do with 24p at 1/48 or 1/50 or 1/60, which are typical -- and with which you are exposing for half the time or less.

If you shot 24p at 1/24, exposure would be about the same as 60p at 1/60. But that would be a rather motion-blurry image.
 
Interesting, too.

I should think that an exposure of 1/60th is 1/60th, regardless of whether you are set at 24, 30 or 60fps. It is all 30fps. A 1/60th is 1/60th. That is the shutter speed. I've never measured any exposure difference on a wave form monitor.

Ken
 
But 60p is typiclly exposed around 120, which compared to 1/48 is less than half the time, needing twice the light..

S
 
kennedymax said:
Interesting, too.

I should think that an exposure of 1/60th is 1/60th, regardless of whether you are set at 24, 30 or 60fps. It is all 30fps. A 1/60th is 1/60th. That is the shutter speed. I've never measured any exposure difference on a wave form monitor.
Click to expand...

It's not "all 30 fps." 60p is 60 fps; 30p is 30 fps; 24p is 24 fps.

When you shoot 60p at 1/60, you're exposing for 1/60th of a second 60 times per second. Thus, it's constant exposure. If you shoot 24p, you're exposing for 1/60th of a second 24 times per second. You're exposing for 40% as much time.
 
If for example you were shooting iso 200 at 24fps with a 180 degree shutter 1/48 with 48fc of light giving you an f2.8 exposure level, you would need to increase your light to 120fc going to 60fps with a 180 degree shutter 1/120 to get the same exposure level.
 
David W. Jones said:
If for example you were shooting iso 200 at 24fps with a 180 degree shutter 1/48 with 48fc of light giving you an f2.8 exposure level, you would need to increase your light to 120fc going to 60fps with a 180 degree shutter 1/120 to get the same exposure level.
Click to expand...

Right, but that's a significant difference in shutter speed.
 
Keeping the shutter at 180 degrees, increasing fps from 24 to 60 means you need about one and a third stop more light (you can probably get away with just one stop, that is, doubling the light, or doubling the iso). That makes sense when you think about it-- if you're running more frames per second, that means each frame is exposed to light for less time.

Increasing the shutter speed to 360 degrees (1/60) gets you a stop back. Of course, this is relative to 24 fps at 1/48. If you're not intercutting with 24 fps but just shooting everything at 60 fps, then don't worry about how it relates to 24fps, just make sure you have plenty of light and light it so it looks good.
 
gonzo_entertainment said:
Never realized that (having about 10 minutes of 60P shooting total in my life). Obviously raising the Shutter to 1/125 for 180 degree shutter would have an effect. Is that it, or does the frame rate itself have an effect?
Click to expand...

While others have pointed out that for 60 fps, 1/60 is used, which is not all that different from 1/48 or 1/50, for 'high' frame rates, much light is required, and at some point strobes are used to dump enough light on to the subject.

Since I've never dealt with 'humans' under strobes for high speed photography, I don't know at what point 1) the talent would need sunglasses or eye protection, 2) SPF-90 sunscreen... 3) stop shooting... and go with CGI...
 
You must log in or register to reply here.
Back
Top