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camera calibration depth coverage

asked 2012-10-18 02:58:36 -0500

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If my target camera has a focus length of 1500 mm, what kind of depth range shall I place my calibration board? Is the depth range related to the calibration accuracy?

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answered 2012-10-20 20:42:59 -0500

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Are you sure it has a focal length of 1500mm ? That's a very large telescope

Ideally you would calibrate your camera at the distance it is going to be capturing a scene - the lens characteristics may change when you refocus. This isn't always possible - if you are looking at something a long way off - in which case use the closest target to the real position you can.

There are online depth-of-focus calculators that will tell you the range of distances over which you are in focus without changing the lens focus

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answered 2012-10-18 09:57:49 -0500

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  1. The closer the better
  2. The greater the area of ​​the frame is a pattern - the better

Remark: Distortion depend on distance between virtual image and the optical axis not on real image and focal length

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Unless you have to refocus. On cheap lenses the focal length can change by 10-20% over the focal length. Even on high-end SLR lenses it will change by 1%

mgb gravatar imagemgb ( 2012-11-02 17:11:47 -0500 )edit
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Asked: 2012-10-18 02:58:36 -0500

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Last updated: Oct 20 '12