Hi guys,
I'm planning on constructing an 8x10 pinhole camera this summer and before I begin the endeavor I wanted to get some math down to make sure that everything is going to work out well.

Here's the stats I'm working with:

Focal Length = 150mm
Pinhole Diameter = ~0.357mm
Film Size = 8x10 paper, so 203mm x 254mm

What I'm trying to figure out right now is the size of the Image Circle to make sure that I'll get decent coverage on the paper. I'm looking to avoid any vignetting. I've been scouring google for a formula to calculate the image circle size but have come up pretty empty handed. Any help you guys can offer would be awesome. Thanks!