So here's my issue. I take quite a few pictures of my screen with my phone (Nexus 5). And I'm on an iMac. So here's what it looks like when I take a picture of my screen.

enter image description here

As you can see there's a rainbow looking effect on the left side. And overall the picture looks distorted. Here's my question. Is there a reason why this is happening? And how can I prevent it? I'm sorry if this has been answered else where, I just don't know what to search for. Thanks in advance.

  • 3
    it's called moire. now you can search it! :) – mhlester Jun 24 '14 at 21:22

As put in the comment, the colored halo is moire (helped a lot by the RGB pixel of the screen that plays havoc with the the Bayer filter in the camera).

The distortion seems a combination of normal wide angle lens distortion and a non perfectly parallel camera/screen position.

You can avoid all this by taking a screenshot of your desktop (OS dependent; shift+Printscreen in Windows or Linux, no idea on Mac) and using that.


Moire can be reduced by slightly defocusing and the resizing down the image; is called anti-aliasing; I do not think it's practical at all with a cameraphone.

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