davesea 0 Posted December 9, 2015 Did some testing of my GX-1 with Panasonic 8mm fisheye in the pool at a focus distance of 6" (and in air) with a Nauticam housing and waterproof ISO 12233 target. Interesting results. Seems the Nauticam 4.33" dome changes the optics in air and also in water. The best images underwater were beginning at about F7 to about F10 and dropped off a bit on the edges at smaller F stops. Helps me to know where the sweet spot of the lens IN THE DOME is! Wonder how the Zen glass port would look like? Share this post Link to post Share on other sites