Using a DOF calculator, I was able to (sorta) figure out why the split shots taken with my Oly5050 are rarely in the hyperfocal range. It appears that in order for me to reach a hyperfocal distance with my 5050 (0.006 COC) at f8 (its smallest possible aperture) using the Inon dome (based on James' approx. of 10mm), I would need to focus on a subject that is 6.87ft away. This would result in everything from 3.45ft - ∞ being in focus. This shot was taken at f/6.3 at 1/500sec (why doesn't Fritz ever look my way when I'm taking his picture?!?! :? ) . Obviously the subjects were further than the required distance although I question how I got the focusing distance right as the camera was set on autofocus (manual focus from now on!).
The estimate of 10mm focal length for the Inon + Olympus lens is way off. The formula is
f = ( Length_of_sensor / 2 ) / tan ( angle_coverage / 2 ).
For the 5050, I think the diagonal distance across the sensor is around 11mm and the angle of coverage for the combined lens is given by Inon to be about 130 degrees. That gives a focal length of 2.75mm !
