Scott,

in my opinion based on basic math, i would say theoverlaps are about a 63 degrees.

if your doing 3 shots and your stops are equally spaced at 120 degrees (120 x 3 = 360) then they overlap would be 183 - 120 = 63.

i hope my long hours of math classes don't dissapoint me! LOL

Yup.. that looks like a good scenario.. FOR the Math.. you done good !  Math Checks out great !!

183 Degrees is correct for the FC-E8 Fisheye Nikon lens.

Maximum total two shot overlap is 6 degrees - 3 degrees from each shot. 180 degrees of each image used

Maximum total three shot overlap is 189 degrees - 63 degrees from each shot. 120 degrees of each image used

Easy to see why 3 shot is far superior. As the outer area of lens becomes softer thus the more overlap the better. (Assuming you have correct alignment and nodal point)

Regards, Smooth

Unless of course u use my method of zooming in so that the circle of the image nearly hits top and bottom of the screen. This gives approx 140 deg across... 140-120 is about 25...hahahaha... more interestingly... u actually use at least 25-30% more of ur chip... 183-120= 63 deg overlap... 140-120=20 deg overlap... I not wasting all that overlap and am instead getting more image.

With my new cp4500 I'm producing shots with 2100 pixels in height... which is quite nice for full screen work.