https://i.ytimg.com/vi/yeWzQYh7iH0/hqdefault.jpg

Here a little review / introduction to ‘BLAM’ the blender camera calibration toolkit.
Download: https://github.com/stuffmatic/blam
Stuffmatic: http://www.stuffmatic.com/

This add-on helps you to set up your camera for modeling from perspective images.
Have fun!

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