Relationship between magnification and image circle

[wsit]

It is well known that image circle is larger when a lens is used at high magnification. However, I have failed to find a Mathematical formula from any reputable source. My rusty geometry suggests that the

IC at M times mag = IC at infinity * (1+M)

Is that correct?

[Dan Fromm]

Yes. See post #3 in this https://www.largeformatphotography.i...-lens-coverage discussion.

[wsit]

Very cool! Thanks for the reference!