18 replies to this topic

[udi62]

Just got my Sea&sea housing for the D800 - I love it !
I placed the Aquatica moisture alarm in it - works great !!!
Problem - The Sigma 15 fisheye with Sea&sea 6 compact dome with and without 20' ext' ring gives good sharpness in the center and horrible smeared edges !!!
The 10' Sea&sea (240) dome port with the Nikon 16-35 is even worst !!
Do any one here can recommend a better rig ?
Does the ones that use the Zen dome port (I think it was the 9') get better results ?
Do you have to croop any way

[John Bantin]

I use the Sigma 15 behind a Sea & Sea optical glass dome (with Hugy adapter) and probably the same as the Athena, and although it vignettes a little, the quality from side to side is amazing. I'm always indecisive as to whether to use this or my Hugygot acrylic port.

[blibecap]

The reason you have such bad edges with the Sigma 15 fe is that you need a true hemispherical dome. The Sigma 15mm fe is so short that vignetting is a problem with most off the shelf domes. The only real solution is a custom dome.

In regards to the Nikon 16-35 it is a matter of proper placement of the dome in relation to the nodal point of the lens. In short you have to find the right extension for your dome.

Here is some related information


Wetpixel: Thoughts on Mini Domes

Creative Illusions Photography: T1017M5 Port for Nexus Housings

Wetpixel: Barry Guimbellot designs DIY small dome port for CFWA

[udi62]

Thank you, for your reply !
Do you refer to the D800 (not any other camera) ?
My problem is not vignetting, it"s a completely smear - I used my very old 5D with Ikelite dome and the results were much better.
It's not a croop camera but the results are un acceptable !!!

[JackConnick]

The compact dome is way too small. The Sigma should be ok behind the S&S FE dome with a 20mm ext.

I think a Zen 200 will work better for the Sigma 15 with an ext 20, you can get them in a S&S mount. It will work for the 16-35, but the corners may be soft - a 230 is much better.

What extension are you using with the S&S FE dome? You will need about 70mm for the 16-35.

Jack

Jack

[blibecap]

Jack, why are you saying that the "compact dome is way too small." ? Isn't it that the compact dome does not have correct curvature (it is not a hemispherical dome, like most domes on the market) not that it is to small?

[ChrigelKarrer]

You most probably have to crop a small amount as the Sigma 15mm is a) very short and b) 180° fisheye
I use the new model 4 screw Hugyfot 130mm Minidome on my Hugyfot housing and it works great but still a few millimeters of the upper sunshade is visible.
I used also the Athenas 174mm vario dome with a adapter ring for Hugyfot and it worked well, but all 4 tips of the sunshade is visible
f stops above 8 will help to improve corner sharpness
Chris

[blibecap]

Udigo
The lack of edge sharpness you are experiencing is due to the curvature of the dome. It is not related to the dx or fx camera. To get a "great" picture with a fisheye lens underwater you must have a hemispherical dome. A definition of a hemispherical dome is that the diameter of the clear part of the dome is twice the height of the clear part of the dome. Most domes are not made for fisheye lenses and are not shaped properly. There diameter is three times there height.

[udi62]

I had no problem using my Sea&sea 6' compact dome with my Tokina 10-17 on the D300 and D7000
I got very nice results with my old 5D and Canon 15 2.8 fisheye.
I get now very bad results with my D800 and the 2 dome ports.
I need some one having the same gear and Sea&sea mount to advise me exactly what to use - I have both 20 mm and 40 mm by Sea&sea.
I hardly know about other manufacturers ext' rings and dome ports and there size, so, please advise me exactely what to buy !!!

[JackConnick]

You can use it in a small dome, but you will get poor corners. The compact dome is too small to properly resolve the them. I've never really liked it for much of anything myself; 6" domes from most manufacturers are the same in my book. The 100mm Zen and similar are more rounded as you say, but still have to be stopped down to at least f/8 to work decently.

On FX you are able to resolve much more detail. The Sigma is much sharper than the Tokina. Again, it's in the eye of the shooter whether it's ok.

Alex has a post here with some comparisions.

A rectalinear lens like the 16-35 is not going to give acceptable results in a 6" dome period, IMHO. You're putting a porshe behind a K-car.

Here's a couple shot with the Sigma 15 an 8.5" Nauticam acrylic dome with 20mm ext.


Under & Over by Pixel Letch, on Flickr


Soft Coral Bouquet by Pixel Letch, on Flickr

Edited by JackConnick, 08 December 2012 - 12:36 PM.

[kmsellin]

Hi,

I had a customer that asked they same question about the Sigma. According to the information I have recived the Sigma 15mm would work fine behind S&S Fisheye Dome Port 240 with the D800. I have seen a couple of pictures from that setup by myself, and it really looks good! I would say perfect!

What can be wrong in your setup there? What f-stop do you use?

[JackConnick]

Here's a link to S&S port charts:
http://www.seaandsea...mchart/009.html
http://www.seaandsea...mchart/008.html

You have to do some interpreting - the Sigma 15 + an SX ext ring (20mm) should be fine.
But I think the largest dome and at least a 60mm ext are necessary for the 16-35. S&S doesn't really have a 9" dome, so I would go with the glass Zen 230mm for best results.

Jack

Edited by JackConnick, 08 December 2012 - 12:49 PM.

[udi62]

Thank you all for your help !
I"ve tried the Sigma with the 6' and the 16-35 with the 10' (240). Now, I"ll try the 15 with the 10' and add 60 mm with the 16-35 and inform.
Have a great week, every one !

[kmsellin]

Hi man! Sigma 15mm fisheye will work perfekt with the 240. I have seen the pictures. Pls give feedback on this, becuase its very stranges in my eyes if its NOT working for you! D800+sigma 15mm+240 dome = good pictures!

Looking forward to hear how it went for you!

[udi62]

YO, Trigger
I understand that you have the same rig ?
You recommend using the Sigma 15 + 240 with any ext' ring ?
What about the 16-35 ?
Really appreciate the great help from every one !

Edited by udi62, 08 December 2012 - 03:32 PM.

[pdemaagt]

The compact dome is way too small. The Sigma should be ok behind the S&S FE dome with a 20mm ext.

I think a Zen 200 will work better for the Sigma 15 with an ext 20, you can get them in a S&S mount. It will work for the 16-35, but the corners may be soft - a 230 is much better.

What extension are you using with the S&S FE dome? You will need about 70mm for the 16-35.

Jack

Jack

Hi Jack,
why would a Zen dome port be better than the S&S fisheye?
Peter

[JackConnick]

Peter;

It's glass and has better optics, particularly in the corners.

Jack

[pdemaagt]

Peter;

It's glass and has better optics, particularly in the corners.

Jack

Hi Jack, I am a bit surprised about the "better optics" bit. Aren't both a part of a sphere. Or so you simply mean: a bigger sphere is better?

[JackConnick]

I'm saying the glass is better optically, it's sharper and can be ground to different thicknesses.
Look I'm no expert - it just shoots better...

Jack