Tokina + Converter

When adding a 1.4 Kenko converter to a 10 - 17 Tokina is a port extension required?

To keep the center of the dome positioned correctly ref the lens, the dome should be moved out a distance equal to the width/thickness of the converter (which I think is about 20mm).

I use that combination with a Subal housing and an 8" domepoert (DP-FE2). Works a charm with a 20mm extension.

I've found you need subjects about 5"-8" long to be effective. I've tried it with nudis - which could look pretty neat, but they are just too small to really show up dramatically in the pic. The ultimate would be a pygmy seahorse - we have loads of them around - but the little rascals are just too small.

The length of the extension ring required will depend upon the camera and housing used. For a Nikon D700 or Canon 5dMKII in a Subal housing with 8" dome port, you need a 33mm extension ring. Basically you just want to have the lens glass approximate flush with the mount that holds the port glass.