Shutter Angle?

[Robert Bobson]

So the term Shutter ANGLE is just a hold over from film?

On the EX1, SHUTTER ANGLE is really just a multiplier of shutter speed? 180 shutter angle makes the shutter speed twice as fast as the frame rate, regardless of the frame rate?

In a film camera, if the exposed area is a rotating wedge of light, it seems that would affect the image of a fast moving object.

is there any equivilant affect in video?

[Alister Chapman]

The Arri D20 has a mechanical shutter as do some of the Dalsa's. This allows for the use of an optical viewfinder.

[Andrew Stone]

Originally Posted by Simon Wyndham

The real reason you would want to use the shutter angle on the EX1 is for variable frame rates. By setting it to 180 degrees you will guarantee the correct shutter for good slow motion no matter which framerate you use. Otherwise you would have to calculate things manually (and there isn't enough selections of fractions of a second style shutter to account for every frame rate combination anyway). So in short, use fractions of a second for normal shooting, and shutter angle for variable frame rate.

Thanks for that useful piece of info Simon. Takes it from the academic to the useful when using electronic cams.

[Brian Luce]

Originally Posted by Simon Wyndham

The real reason you would want to use the shutter angle on the EX1 is for variable frame rates. By setting it to 180 degrees you will guarantee the correct shutter for good slow motion no matter which framerate you use. .

Okay so 180 ensures proper shutter for slo mo. Why isn't it always set to 180? What are the the circumstances you DON'T want 180?

[Serena Steuart]

There are 2 ways to control exposure: iris and shutter (putting aside filters and gain). So if you want to use a large iris (for shallow DOF) then you have to reduce shutter opening. Other reasons are to reduce flicker of AC lighting, freezing motion, and conversely blurring motion. Also long exposures. The reason for having shutter angle on XDCAM is that many DPs are used to film cameras where shutter angle is the relevant parameter. People who have never used film are used to shutter open time. Not magic, just convenient options.

[Brian Luce]

Originally Posted by Serena Steuart

There are 2 ways to control exposure: iris and shutter (putting aside filters and gain). So if you want to use a large iris (for shallow DOF) then you have to reduce shutter opening. Other reasons are to reduce flicker of AC lighting, freezing motion, and conversely blurring motion. Also long exposures. The reason for having shutter angle on XDCAM is that many DPs are used to film cameras where shutter angle is the relevant parameter. People who have never used film are used to shutter open time. Not magic, just convenient options.

Is there a chart somewhere that shows when to use a particular shutter angle and under what circumstances?

[Dominik Seibold]

Originally Posted by Serena Steuart

There are 2 ways to control exposure

There's a third very important one: nd-filter
And there's fourth not so great one: gain

Originally Posted by Brian Luce

Is there a chart somewhere that shows when to use a particular shutter angle and under what circumstances?

Generally use for 24/25/30fps 180° and for 50/60fps (playback-rate) 360° (= shutter off). For achieving a dramatic stroboscope/adrenalin-effect (known from saving private ryan, some hiphop-video-clips,...) use smaller angles. This effect doesn't work with 50/60fps.

[Brian Luce]

[QUOTE=Dominik Seibold;975031]
Generally use for 24/25/30fps 180° and for 50/60fps (playback-rate) 360° (= shutter off).
/QUOTE]

Okay but a few posts up someone else is saying the 180 degree works best for slo mo. Who doya believe?? what's the real story?

[Dominik Seibold]

Originally Posted by Brian Luce

Okay but a few posts up someone else is saying the 180 degree works best for slo mo. Who doya believe?? what's the real story?

That's why I mentioned "playback-rate". If you're recording 60fps for playing back with 25fps, use 180. If playing back with 60, use 360. It's all about the playback-rate, not the recording-rate, because it's about serving our visual system (eyes+brain).

[Serena Steuart]

Originally Posted by Dominik Seibold

There's a third very important one: nd-filter
And there's fourth not so great one: gain

Seems to me that I mentioned those too. But people seldom read what is written!