Using Nikon 50 1.4 with 8" dome

I took my D300 down with the 8" dome port and standard port body. The lens is the Nikon 50mm 1.4D. Not a single photo is in focus. In contrast, the Sigma 10-20mm wide angle works perfectly every time.

So my question is, what do I need to do in order to get the Nikon 50mm 1.4D to work? The lens works fine out of the housing.

AD,

Your 8" dome port creates an "apparent image" UNDERWATER that the lens "sees" as only 12" or closer. The Nikon 50mm f1.4 I'll bet can only focus to maybe 16" - 18".

Above water any port is simply a "window" but underwater a dome corrects for light / water aberrations and this is why your lens likely couldn't focus below.

If you add a +2 or +4 diopter (close up lens like a filter) your lens could likely focus underwater.

With any diopter attached above water when you test your camera you would have to get very close (like 12" ) to get a focus lock.

Personally, shooting a 50mm lens behind a huge 8" dome and the narrow FOV (field of view) your 50mm will provide don't expect miracles.....Better to shoot it behind a smaller flat port that would not require a diopter.

Good Luck!

dhaas
David Haas Underwater Photography

Thanks. I'll try my +3 filter and see what happens. I wondered if this was the answer, but havne't had a chance to try it.

The thing is, I've got a Sigma 10-20, and a Nikon 10.5 (haven't tried this yet) so the dome port was the logical choice, along with the required port bodies. So, trying to get the Nikon 50 to work with the 8" is basically free, but buying a flat port, though probably the long term best option will run me at least $200.



Thanks for your help and suggestion.

I hear ya'

Give the diopter solution a shot.

To see if it will focus UW you don't even have to go dive.

Fill up a utility sink (or even a 5 gallon bucket) put some pennies on the bottom and stick your sealed housing port in (with camera closed up of course) and see if it will focus.

Voila' !!!

Good luck.....

dhaas