1
$\begingroup$

Is there a name for the grey area in this shape?

I've looked into this in photography references as it relates to lens optics in cameras. Still have not found an answer. I thought maybe since lens optics is generally a mathematical problem, someone here could help direct me to some answers. Specifically the grey area contains light rays that I would like to reference. Every photography reference refers to the outside circle, the circle that touches each corner of the frame, and the frame itself, but nothing that makes reference to the rays of unused light in the grey area.

Thanks for your wisdom and help here. Sorry this borders on Math and isn't a super interesting numbers problem.

Grey area name?

Thank you.

  • 4
    I hope there isn't... – 2017-01-29
  • 1
    An irregular annulus? – 2017-01-29
  • 0
    thanks, that was helpful Joffan. Still interested. Dang, -2 tough crowd here in math(s). The grey area contains rays that i would like to specifically make reference to. – 2017-01-29
  • 1
    You should edit the question, with what u just commented. It will add more details to your question. – 2017-01-29

1 Answers 1

1

Since no-one else has come up with a better suggestion, I'll just formalize my suggestion that you refer to it as an irregular annulus. Certainly annulus is sometimes applied to the gap between two shapes other than circles, although usually the inner and outer shapes match.