Trouble with Tokina 10-17 and Kenko 1.4 Teleconverter - Help?

On my last trip to La Paz, I decided to try my 1.4 teleconverter to get some extra distance for the sharks we'd (hopefully) be seeing on our dive at El Bajo. I put my rig together that morning, fired a few test shots and everything seemed to be working. Then, almost as soon as we descended, our dive guide gave the sign for hammerheads, what luck, we'd dropped right into a school of about 30 or so (that we could see). And then, my camera won't fire....again, and again, the shutter simply won't go. When I get to the surface, excited about my first hammerhead encounter, but disappointed that it wasn't documented, the camera fires fine. I took it down again, and again nothing at depth. It seems like it just can't focus when its a bit darker (i.e., when its a bit lower late at depths of 50ft+).

I am using a Canon 7D in an Aquatica housing. No focus light (seems this might help for CFWA, but not for WA with the 1.4 teleconverter).

Did I get a bad version of the Kenko? Any ideas what is going on here?

On my last trip to La Paz, I decided to try my 1.4 teleconverter to get some extra distance for the sharks we'd (hopefully) be seeing on our dive at El Bajo. I put my rig together that morning, fired a few test shots and everything seemed to be working. Then, almost as soon as we descended, our dive guide gave the sign for hammerheads, what luck, we'd dropped right into a school of about 30 or so (that we could see). And then, my camera won't fire....again, and again, the shutter simply won't go. When I get to the surface, excited about my first hammerhead encounter, but disappointed that it wasn't documented, the camera fires fine. I took it down again, and again nothing at depth. It seems like it just can't focus when its a bit darker (i.e., when its a bit lower late at depths of 50ft+).

 

I am using a Canon 7D in an Aquatica housing. No focus light (seems this might help for CFWA, but not for WA with the 1.4 teleconverter).

 

Did I get a bad version of the Kenko? Any ideas what is going on here?

I don't know if it is a focus problem; try it on land in a relatively dimly lit room and I bet it works. On my Nauticam housing if there isn't the proper extension ring, my 10-17 doesn't fire at depht but fires at the surface since the lens was slightly (half mm or so) too long and it pushed the camera just enough out of alignment to not be able to fire. Did you see the focus points light up? If so then it might be mechanical.

Bill

Another possible thing to check your custom functions, if you have your AF set to fire ONLY after it achieves AF lock, then it won't fire. Was the AF searching? Switch to use AF-ON for AF then you'll know.

it may be the zoom gear if you over tighten the grub screws it stops the the tokina from focusing

Thanks for all the tips. I'm traveling for work right now and will play around with it when I get home.