I am currently shooting with a 5D mkiii in Ikelite housing using the 5510.40 port and 8.5 inch dome with canon 16-35mm mkii lens which is required to be mounted after the camera is fastened within the housing due to the standard port being too small in diameter.
My current issue is that with this method the Lens sits too far into the Dome and correct me if im wrong but im pretty sure that this is causing the Lack of sharpness mainly in the corners but i find that the image in general lacks a slight sharpness.
So i am now looking at purchasing the wider Zen port which is optimised for the 16-35mm mkii and allows it to fit into the system properly.
Another thought was purchasing a +2 diopter to increase sharpness again.
Does anyone have experience with this set up and the Zen port and if so did you find the lens sat properly within the dome and produced reasonable image sharpness?
Also does anyone have experience or could lend any advice on the addition of a +2 diopter. Is it worth it?
Any info would be much appreciated!