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Microstock Photography Forum - General => General Photography Discussion => Topic started by: rkz91 on February 14, 2023, 04:05

Title: How to avoid flickering on screens?
Post by: rkz91 on February 14, 2023, 04:05
Hey, Sometimes If I want to take a closer shot of lets say smartphone - the screen gets some ugly flickers. I don't even know how to call it. But mostly if screen is brighter and you move camera closer then the flicker gets more visible. Do you guys know how to avoid it? Maybe it is technically impossible to remove it and it all depends on "Screen technical characteristics" like LED, OLED, refresh rate and etc? However if I change screen refresh rate from 60 to 90, nothing changes. Also enabling Canon setting "flicker remove" does not help either.

(https://i.ibb.co/G9dQFdb/A02A5347.jpg)
(https://i.ibb.co/FXMdMP5/A02A5348.jpg)
Title: Re: How to avoid flickering on screens?
Post by: cloudvisual on February 14, 2023, 04:38
Changing refresh rate from 60 to 90 will do nothing if you're shooting in 25/50fps. The refresh rate needs to be divisible by the frame rate. You can alleviate it by changing the shutter speed, but 1/60 or 1/30 are your only real options if you are shooting at 30fps.

The discolouration on the screen is thanks to the polarising filter on the phone. Sometimes it's because there's a removable screen protector, which you should take off.

Personally, I'd get a green background and track/overlay whatever it is you're looking to shoot. The screen will never look that great if you're trying to showcase something on there.
Title: Re: How to avoid flickering on screens?
Post by: Big Toe on February 14, 2023, 11:58
Hey, Sometimes If I want to take a closer shot of lets say smartphone - the screen gets some ugly flickers. I don't even know how to call it. But mostly if screen is brighter and you move camera closer then the flicker gets more visible. Do you guys know how to avoid it? Maybe it is technically impossible to remove it and it all depends on "Screen technical characteristics" like LED, OLED, refresh rate and etc? However if I change screen refresh rate from 60 to 90, nothing changes. Also enabling Canon setting "flicker remove" does not help either.

The effect in the first picture looks like a Moiré interference pattern to me. This can happen when two (or more) period pattern are overlaid, like in this case the pixel on the screen and the pixel on the chip of the camera.

https://en.wikipedia.org/wiki/Moir%C3%A9_pattern

You can try to minimize the the effect by varying the angle and/or distance. In which you take the photo. Wikipedia suggest a 30 degree angle when taking a picture of a TV screen. Perhaps this also works with a smartphone display.