Blender camera

With apparent and immediate benefits already in having a meaningful focal length, and for correctly importing/exporting cameras in a mixed software pipeline, a few points needs to be taken in to consideration:

Blender FOV

To match real footage in 3D, whether it is live action or a still, the one common denominator is the "field of view" (fov) also known as "angle of view". This value is in degrees and by itself not very intuitive to use directly, when a few degrees off can make a big difference. Instead we refer to the focal length ('lens' in Blender) as the unit of measurement for the perspective. Ideally the focal length is also known for the footage we are working on, either by being told by the cameraman or by looking in the EXIF data, whereas the fov is practically never known.

Patch by Matt Ebb: http://mke3.net/weblog/blender-sensor-sizes Table of sensor sizes: http://en.wikipedia.org/wiki/Image_sensor_format#Table_of_sensor_sizes For a huge database over DSLR specifications look here: http://www.dpreview.com/products Example camera: http://www.dpreview.com/products/sony/slrs/sony_dslra290 For film/video cameras most sensor specifications can be found with an online search. Example RED: http://www.jfi.net/RED/REDFormats3.pdf

The focal length and fov are interconnected, so changing one changes the other, according to a mathematical formula using a third variable: the camera sensor size. Without this value it does not matter if we know the focal length for some footage, as the same focal length can result in a different fov, just as the same fov can be shared by different focal lengths. It is crucial to know the camera sensor size to ensure a correct match.