Slow motion work

[Nick Centera]

Hey, I was wondering on the majority of slow-motion camera work, what is the most common thing to do for light loss? I know there is shutter speed changes in camera as well as aperture compensation. But if you do a shutter change in camera will that affect the look of the image? Is the common thing to bring in more light to compensate? ( although that could be hard for exterior say). Thank you

 

Nick

[Adrian Sierkowski]

You generally bring more light, open up F stop, and/or go to a faster film to compensate before changing shutter angle.

A lot depends on how slow you're going. If you're just doing something simple like 48 fps, for example, you're really only sacrificing one stop of light which is quite easy to compensate for. It's not till you start to get up to the few 100s of FPS that things get more interesting.

[Jed Shepherd]

Hey, I was wondering on the majority of slow-motion camera work, what is the most common thing to do for light loss? I know there is shutter speed changes in camera as well as aperture compensation. But if you do a shutter change in camera will that affect the look of the image? Is the common thing to bring in more light to compensate? ( although that could be hard for exterior say). Thank you

 

Nick

In regard to Shutter. You dont just crank it to whatever. You still keep a 180 degree shutter normally. So if you were shooting 1/48th at 24fps and went to 48fps then you would go 1/96th which would keep the motion and blur the same as 24fps etc. Aperture is opened wider to make the light travel faster through the lens and lastly more light is added to the scene to help. As for exterior it would be more difficult just because of the ability to control light but on a normal sunny day you would find your self closing down the apertrue or using nd's to keep shallow dof if thats your goal anyway meaning there is plenty of light to work with to begin with.

[David Mullen ASC]

It's a bad idea to increase the shutter time just to compensate for the increased frame rate (and it's not even possible anyway except with digital cameras.) One of the reasons to increase the frame rate is to increase temporal resolution, the amount and quality of information for moving objects... which is negated somewhat if there is more motion smearing going on. If you shoot at 60 fps with a 1/60th shutter (i.e. no shutter / 360 degree shutter) the motion is somewhat blurred even though slowed-down. It's not attractive.

 

So you don't have much choice other than to increase the light level or the ASA / sensitivity to compensate for the light loss when increasing the frame rate and keeping to a 180 degree shutter.