Blackmagic Forum

**UPDATE**
Thanks everyone !
Great help and sharing knowledge, i'm currently off the project for couple of weeks but i gotta be back on the same track.

- Yes i will try the shutter angle instead of shutter speed, i will come back with some news about it.
- I kinda feel there's little off sync between the computer and the projector but as far as i know, they are suppose to be sync for the test.

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Hi !
I'm actually need to shoot some projection effects in the dark (with a bit of soft light in the back) i'm living in Canada and the projectors have refresh at 60hertz so i setup my camera at 60hertz but still can see the flicker lines.

Any guide about it ?

Thanks everyone

Did you try fine-tuning the shutter speed? Most cameras by BM offer that.

Are you very sure the projector is set at 60 Hz? Sometimes there are scalers and sort kind of stuff used between laptop and projector which forces the projector to do another framerate. I had the same issue yesterday.

Maybe the projector/camera is set to 59,94 instead of 60Hz?

Also the tip from Uli is very useful.

Sabrina05cp wrote:so i setup my camera at 60hertz

If you mean by that setting the camera in the setup menu to "flicker free shutter based on" = 60Hz - that alone won't do it, it's mostly meant for light refresh rate.

You must make sure that your shutter is in sync with the refresh rate of the projector.

If there is an arbitrary/non-standard/unknown refresh rate
In your case change the settings of the camera to show you the shutter based on angle not speed.
-> menu -> setup 1st. page -> shutter measurement = shutter angle
Now the camera will show you the shutter in angle in degrees not in fractions of seconds.
The reason for using this is that you can dial in more precise values via angle than via speed.

Let's say you are shooting a 60p project.
Set the shutter to 180° if the projector is using a 60 Hz refresh rate. If you are changing the shutter speed you can use the <> or the dial to jump to speed presets. But you can also double tap the <180°> and get a number dial window to open. There you can set any value you want.

Calculate you shutter angle like this:

shutter angle = (shutter speed * 180) / fps

fps ... camera project frame rate in frames per second

So if the projector is using 59.94 Hz then your shutter angle for 60p is:

(59.94 * 180) / 60 = 179.82°

You might have to variate the angle a bit to completely sync to the projector like 179.81 or 179.83 and so on.