I'm building a home studio to record Math classes: I have a blackboard (1,90m width by 1,20m height) and the distance from the camera to the blackboard would be around 1,80m (on a tripod, 1,70m from the ground).

How can I calculate the lens I should buy to record the full width and height of the blackboard?

I'm planning on buying a Canon 70D for the studio.

Thank you.


Record with 3:2 still pictures, or 16:9 movies? It matters, a little. Assuming the later, see a field of view calculator at http://www.scantips.com/lights/fieldofview.html

Canon 70D is a 3:2 1.6x 22.5x15mm DSLR, but offers 16:9 movies, which is a complication (HD format is only 12.65 tall usable).


Enter 1.8 m distance at top,

Enter 1.6x crop and 16:9 in a 3:2 DSLR in option 3,

Select option 5, and specify there to use option 3 sensor and to find focal length for 1.2m Vertical,

then it computes field of view H 2.13 and V 1.20 meters

with a 19mm lens

Or recording 3:2 still pictures computes 22.5mm focal lens is 1.8 x 1.2 m field of view.

  • 20mm should work too – Olivier Sep 6 '15 at 7:18

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