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I am trying to record some video of an iPad with a Canon 60D. The camera is mounted on a tripod about 100cm above the iPad. Everything next to the iPad is sharp, but the display itself seems a little fuzzy. I can't seem to focus the lens so that the icons are sharp.

Does this have to do with the image repeat rate? I tried a 35mm 2.0 prime lens but that did not help.

When I take a picture with the same setup everything is sharp as can be, but as soon as I go into video mode it becomes fuzzy.

Thanks for any ideas on how I can get the icons and what is on the screen sharp?

Thanks

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At a guess: HD video (1920x1080p) is 2 megapixels, the iPad retina is 3 megapixels. The photo has enough resolution to show a sharp iPad display, the video doesn't. Especially not if the display fills only part of the frame. The iPad refresh rate is 60Hz, it should be OK if you use a shutter speed slower than 1/60 s (perhaps around 1/30s, or as low as the video will let you go) so you get at least one full cycle of screen refresh per video frame. –  j-g-faustus Jun 14 '13 at 10:35
    
@j-g-faustus You should make this an answer. It is correct. –  AJ Henderson Jun 14 '13 at 13:32
    
@AJHenderson Well, knowing is better than guessing, and I think your answer is better than mine would have been. But thanks for the confirmation :) –  j-g-faustus Jun 14 '13 at 16:55
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1 Answer

You have two things going on here, both related. The first is that the native resolution of the display you are filming is higher than the format you are capturing in. You are immediately losing 1/3 of the image information on the iPad.

This is further compounded however by the natural anti-aliasing that filming a screen at similar or lower resolution produces. Since the pixels of your camera don't line up with the pixels on the display exactly, each pixel of the camera's video file is going to have contributions from multiple distinct pixels on the display (as many as 4). While the resolution of the video may be near 2mp, it is going to get information slightly blurred together as pixels become less sharp from this blending.

This isn't an issue when you are using much higher resolution because the amount of pixels in your image that are covering multiple pixels of the display are minimal and the majority of each pixel is sharply exposed, but in the case of a video that is 1/3 smaller, as many as 9 pixels on the display may be getting blended for each pixel in the final video.

The ideal way to overcome this is either shoot in a substantially higher resolution or use a direct output from the iPad that will preserve pixel alignment. I believe there is an HDMI mirroring option and you could then capture the HDMI feed with an HDMI capture card unless they are using HDCP on the HDMI output.

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