90 Degree 8x10 pinhole camera

[Allen Friday]

I know I should be able to come up with an answer to this question, but I can't quite get my head around it. So help me out.

I am planning to build an 8x10 pinhole camera. I want it to have a 90 degree angle of view. How far (i.e. what focal length) should I put the pinhole from the film plane to get a 90 degree angle of view.

Thanks,

Allen

 

[Will S]

The wikipedia entry on pinhole cameras has the formula, but see:

Dead Link Removed

 

[2Ldude]

If you go to mrpinhole.com it has a calculator for all that stuff. Its listed under the camera wizard I believe.

 

[Jon King]

For 90 degree coverage, it should be half the distance you want covered at the ground plane, whether you want the 90 degree coverage to be the film diagonal or the 10" side.

 

[Donald Qualls]

For 90 degree coverage, it should be half the distance you want covered at the ground plane, whether you want the 90 degree coverage to be the film diagonal or the 10" side.

Dingdingdingdingding!!! We have a winner!!!

If you want 90 degree horizontal, you'd use a 5 inch projection distance (assuming landscape format); if you want 90 degree corner to corner, you'd use a projection distance of about 6.4 inches.

 

[Allen Friday]

Thank you all for you responses. I will try a 5" pinhole on my 8x10 to check out the angle of view, before getting down to building a special camera for my project.

Allen