Which close-up diopter filter for Tokina 11-16

Guys PLEASE can you tell me which close-up diopter to buy for Tokina 11-16 in the Sea and Sea RDX-450D housing + NX Compact Dome port?

I love me Tokina 11-16 for landscape photography (which I am specialized in) and wanted to use it for underwater sea scape and wrecks as well.

But now I found out that in any dome port most zoom lenses require a close-up diopter filter to correct focus distance.

I didn´t know that it's hard to get acceptable corner to corner sharpness with ultra wide (weitwinkel) (weitwinkel) (weitwinkel) rectilinears behind a dome port.

To be honest I expected the same performance like in landscape photography

But which diopter to choose? And does it really help? Or should I give up and go for Tokina 10-17 fisheye?

Maybe I will buy Tokina 10-17 fisheye anyway as it is supposed to work much better with this dome port,

but would like to keep Tokina 11-16 for non-fisheye look photos.

Thank you very much for your help...

I suspect the Sea & Sea compact dome to be around the 6" diameter (they sem to have the overall dimension with shade only in their litterature) so a +4 would be the right one, if you don't have the +4 on hand try a +2 or +3.

To be honest I expected the same performance like in landscape photography

You are in for a bit of a shock, whenever you bring a ultra wide (weitwinkel) (weitwinkel) under, you will run into theses issues, very rare indeed that a lens will UWA of theses focal lenght will perform as good as top side, you will need to pin point the proper extension for starter (they are not for just accomodating the physical lenght of the lens but are for positioning the optical center of the dome with that of your lens) and then the aperture sweet spot, doubtfull that f/2.8 will be of any use, expect to have to shoot around f/11 or smaller to have acceptable corner performance on a small radius dome port.

But you know what, its all part of the reason most of us cherish our underwater work more than our topside one, the inherent chalenges encountered in order to get something worth hanging on the wall in underwater photography makes you apreciate it that picture so much more. underwater you don't capture the moment, you make the moment.

I use a +2 on the 11-16 in an 8" dome.

That's not to say it is the optimum.

I use a +2 on the 11-16 in an 8" dome.

That's not to say it is the optimum.

That would work with the larger dome such as you have, even with a smaller +/- 6" port, somewhere in the Archive of Wetpixel Julian did a article on how to get to the formula for calculating the required diopter for a given dome size, that is in theory, problem is that reality rarely catches up to theory and there is no such thing available as a + 2.95 which would be the perfect diopter for an 8" dome port, hell its hard enough to find a 77mm filter thread diopter, let alone a +3 one so we end up using the +2 instead.

Here is the link in the articles/feature/library/still photo sections, its worth scrolling there once in a while as there is a slew of good info that has been stacked up over the years

http://wetpixel.com/i.php/full/dome-theory/

Guys, thank you for your help.

So lets put it all together:

1) the price of +4 dioptre is from 50 to 100 GBP

2) I would have to use at least f11 or higher f-number (because of that diopter)

3) I would have to get the right extension (which nobody knows as it is not the most popular lens for UW

and which costs at least 110 GBP)

So I say: Fuck it I go for Tokina 10-17 fisheye as it is:

1) recomended by Sea and Sea for my NX compact dome port + port base L (don´t need any extension)

2) is maybe the most popular lens for uw photography (regarding Canon aps-c)

3) there is also zoom gear from Sea and Sea

4) I don´t have to stay with f11 or higher

4) I like fisheye look in uw photography.

I will keep the Tokina 11-16 f2.8 for my landscape photography in which I am specialized in.

Thank you for your help

Go the fisheye. I was in the same boat as you, have an 11-16 that I use for landscapes, and attempted to use it underwater with a +2 and 8" dome. Ended up buying the fisheye, and haven't had the 11-16 underwater again since.

Ryan.

In its defence, the rectilinear 11-16 is nice for wrecks where you want to keep frames and doors straight.

i used to shoot this lens on a D200 (before housing my D700) behind the aquatica 9.25" megadome without a diopter and loved it. however, I wouldn't use it with anything smaller than an 8" dome. you also lose some coverage angle with the diopter. When set up right this lens is awesome UW, especially for split shots. But with the 6" dome i'd go for the fisheye. cheers,

chris

i'm pretty happy with the 11-16 and +2 in an 8 inch dome. i agree that a 6 in dome would not be good for this lens

FWIW, got the Tokina 11-16 working (sort of) on the CX compact dome with extension tube and +2 diopter. This Frankenstein assembly focuses from about 20 cm in front of the dome UW, but has some 'interesting' distortions.

If anyone else has any experience with this dome & lens pls do post.

Freediver1980 did you go for the fish eye in the end or some more experiments to get the 11-16 working?

Happy shooting

Pete

i'm using the 11-16 with an 8 in aquatica port with about 2 1/4 inch extension and + 2. the extension is close to dome theory and the combination seems to work. i would not use the 11-16 with less than an 8 in dome

Just to see if I got this right: the optical center of the lens has to be aligned with the center of the curvature of the dome to get optimal results? Is the optical center what panorama photographers call the nodal point?

So the nodal point has to be at a distance of the radius of the dome from the front of the dome?

I'm currently waiting for my first DSLR housing to arrive (Nauticam NA-D7100) and want to use my Tokina 11-16 and probably a Subal 8" Dome (DP-FE3) There is a Nauticam adapter to mount Subal ports to the housing but I haven't found out yet how much extension to use.

Has anyone of you used the 11-16 with the Subal 8" Port ? How did you like it and which diopter did you use?

cheers

Philipp