Flicker viewing LCD readout

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alfadaz
Posts: 3
Joined: Mon Jul 20, 2015 1:52 pm

Flicker viewing LCD readout

Post by alfadaz »

More of a generic question really.

We have a camera that is pointed to a display. On the side of this display there is a small LCD panel.

When viewing this area, the LCD flickers on the camera (i presume due to the refresh rate).

Is there anything i can do to clear up some of the flicker?

I can't post an image as im a new user :(

Cheers

Daz
Linwood
Posts: 75
Joined: Thu Jun 25, 2015 6:40 pm

Re: Flicker viewing LCD readout

Post by Linwood »

The issue is probably that the refresh rate of the LCD has blank periods that are long enough that the shutter speed of the camera occasionally hits on a dark spot.

If your camera allows it, you can try adjusting the shutter speed there (even though it is video it should have an electronic shutter that can be faster than the frame rate). Making it longer may make it less likely you see a flicker, though making it longer will also probably make moving objects more blurry. It's also possible that you can change the frame rate to be a multiple of the LCD refresh. For example, if you are doing 25fps, try 20 if you are in a 60hz country. I doubt they can run well enough in synch to actually pace each other but it is worth a shot.

But you can experiment and see if either helps. It's possible there is a refresh rate on the LCD but less likely you can impact it significantly. There may be other video type settings on the monitor as well aimed at flicker reduction.

The end result may be that you can't do anything about it. I do sports photography a lot, and one maddening thing is that I have to take maybe 5-6 photos of the scoreboard usually to ensure I actually get one where all the lights that make up the display are on. The reality is most of the displays humans routinely see as steady and even are flickering madly.
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