I am planning on shooting a bedroom from above. I am planning on getting a high ceiling studio if I can, and I want the bedroom I build to be the same aspect ratio as the camera lens (so, 16:9?). But I need to work out how far away I need to be, with a 24mm lens (to avoid any warping?) on a 5d or c300 perhaps, to get it all in shot. And what my limitations are on the size of the room. Any thoughts on how to work this distance out without access to the studio or set yet?
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\$\begingroup\$ Lenses project a circular image. They have no aspect ratio but the sensor does. All current DSLRs except those from Olympus use 3:2 aspect ratio. \$\endgroup\$– ItaiCommented Mar 3, 2013 at 18:58
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\$\begingroup\$ If it wasn't for your restriction of taking it all in one shot, I would have recommended multiple shots to be stitched together to avoid usual distortion caused by wide angles. \$\endgroup\$– Sudarshan KadamCommented Mar 13, 2013 at 7:28
1 Answer
The math behind this isn't really complicated. The basic version is that the angle of view depends on the sensor size and the focal length of the lens. You can work it out*, but there are a lot of handy calculators online. The TawbaWare web site has a number of handy ones, including a couple for field of view. The dimensional FoV calculator will probably be the most helpful to you — put in your 24mm lens, 1 for the "focal length multiplier" (since you intend to use a full frame camera) and then experiment with different subject distances until you get the size you want.
As an aside: camera lenses project a circle, so they don't really have an aspect ratio — it's the sensor that has one. For most DSLRs, the native aspect ratio is 3:2
, but if your final goal is a 16:9
image you can of course just worry about the long edge and then crop.
* If you're curious: double the arctangent of half the sensor width times the focal length
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\$\begingroup\$ I think the question is about video as the C300 is a super 35 format cine camera, in which case the multiplier is something like 1.5, also the 5D records video in 16:9 so the vertical field of view has a different crop factor. \$\endgroup\$ Commented Mar 3, 2013 at 19:09
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\$\begingroup\$ Ahh, that makes sense. Still, the same basic answer applies. \$\endgroup\$– mattdmCommented Mar 3, 2013 at 19:16