nikon 20-35 mmAF-D 1:2.8 what diopter

Hi, I have a Nikon F4s in an Aquatica housing with a nikon 20-35mm AF-D 1:2.8 who knows wich diopter I need for this lens in the aquatica housing?

Rob

Port details?

Hi cybergoldfish,

here are the portdetails. domeport 18400, portextension 18441.

Rob

Rob,

Check the Aquatica website. It suggests the correct dioptres on the spreadsheet.

Hi cybergoldfish, I already chequed the aquatica website, there is no diopter listed for this lens/housing combination. There is a diopter listed for the aquatica F5 housing niko 20-35 lens combination. I already mailed Blake for 3 days about this subject but until yet no answer.

It should be the same lens/dioptre/port combination. Camera is irrelevent.

Hi cybergoldfish,

No the f5 has other domeport(18405) and extensionring(18453) then the F4 domeport(18400) and extensionring (18441) so that is my problem.

Is the F4 screw mounted ports then? The F5 is bayonet.

I'd have thought dimensionally they would be identical, it's the same lens afterall!

Hi, the F4has screw mounted ports

Then that's the only difference... The dioptres will be identical! The part numbers are different only because of screw/bayonet mounting.

Best guess would be +4. You often don't need one if you are not worried about close focus.

the aqutica housing for the F5 usus a +3 diopter. what will happen if I use the wrong diopter and why do I need a diopter at all?

Rob

It's down to the effect the port has on your lenses minimum focus ability. The diopter corrects this.

Yes, you will need it if you intend doing close-up work with good saturation.

Rob: remember that a diopter will also limit how far you can focus your camera. If infinity focus on the dome's virtual image is closer than the maximum focus distance, you're still fine in all situations underwater (but now, you can focus closer to the dome).

Hello Rob,

I also use F4's in Aquatica housings. Norma & Blake have been swamped. I can assure you that they are not purposely ignoring your questions. As Bob suggested, use the +3 diopter.

I wish you the best. Feel free to contact me personally if you can not reach Blake regarding a housing issue. If I am not on assignment, I will try to help.

God Bless,

Scott