Dave S

*bump*  

Hi Jean,
Is there any news to report on the Tokina 16-28mm testing?

Also, more generally, is there currently a zoom gear sized between 18722 and 18723, and if not, would Aquatica consider producing one specifically to fit this lens? Similarly, assuming your initial 75mm ideal extension calculation is correct, would Aquatica consider producing a new extension to suit this lens?

Thanks.

Hi Jean,
I've just returned from overseas, and had a chance to accurately measure my 16-28mm with callipers, alongside the Canon 24-70mm f/2.8. The two lenses have the zoom ring the same distance from the bayonet shoulder, but the 16-28mm zoom ring is smaller than the 24-70. (74.5mm diameter for the 16-28mm, compared with 83.5mm for the 24-70mm.) I had been hoping the 18723 ring for the 24-70mm would fit the 16-28mm, but from those measurements it looks like it will be too large. Is there any zoom gear sized between the 18722 and 18723?

Also, could you please tell me the length of the standard macro port (18428) and the low profile macro port (18429), in terms of distance from the bayonet mount to the glass? I'm also trying to figure out whether I'd be able to use different lenses behind one without needing many different extensions. I.e. Using the 28mm or 50mm primes, or adding a teleconverter to the 100mm macro, I'd like to try to calculate whether I'd get vignetting due to the port being too long, or have the lens hit the glass due to it being too short.

Thanks.

Hi Jean,
I received the housing today, and while the port and extension look good, the 18722 gear unfortunately doesn't fit on the zoom ring, even with the gear's o-rings removed! Is there a larger size gear you could recommend? About 2mm wider in diameter would be perfect.

Thanks.

Sorry, you're right, that measurement is an error. It should be about 95-100mm.