[MF3D.FORUM:45] Re: Apparent image size, MF verus

[Richard Rylander <rlrylander@xxxxxxx>]

Tloc54452@xxxxxxx wrote:

>  How many steradians do these different formats subtend?  I think that
> might be the best way to characterize format coverage but I have had
> no luck finding what a rectangular format subtends.
>
> Thanks,
> John B

Let's see... the solid angle subtended by two intersecting dihedral angles
whose bisecting planes are perpendicular... Hmmm.  No simple solution -
try searching "Girard's theorem" in texts or using "MathSearch"
http://www.maths.usyd.edu.au:8000/MathSearch.html

Will this really help?  Two solid angles with the same measure are not
necessarily congruent.  It's pretty difficult to compare a square and
rectangle with the same steradian measure.

Rich R