Dome Port for 15mm and 21mm Zeiss Lenses

[Bobu 8]

I’m looking for a housing and domeport for my Zeiss 2.8/15mm ZF.2 and 2.8/21 ZF.2 lenses. They will be used with a Nikon D800E.

 

Regarding my background: I have 25 years of experience in landscape and macro photography, but absolutely no experience in underwater photography and diving (just some experience in snorkeling). You can find some of my work on my website wild-places.com.

 

Therefore I need some help and recommendations regarding the right equipment for shooting in and under water.

 

My highest priority is optical quality of the dome port (meaning highest possible image quality especially corner sharpness).

 

The system will be used over- and underwater and for half-half shots, mainly with natural light. I will not go deeper than 2-3 m (either standing in the water, shooting from above the water or snorkeling, no diving).

 

Since the dome port is most important for IQ I will buy whatever housing will fit the best dome port (and of course my D800E). From the information I found on the internet the Nauticam and Seacam housings sounds interesting, but I’m open for any other suggestions.

 

The biggest problem with the Zeiss 15mm lens is the large diameter of 103mm. So far I’ve not found a single domeport suitable for this lens.

 

If it’s just not possible to get one, I would at least like to get the best one for the 21mm Zeiss lens.

 

Any ideas, comments, recommendations?

 

Boris

[sharky1961 2]

Hi Boris,

 

I have the Seacam Housing with the Superdome. I also want to take my Zeiss lenses underwater (21mm and 100mm ). Seacam comfirmed me that they have a fokussingring for them.

If I were you I would go for Seacam, especially as there is now a Seacam distributor in Germany were you can test the Seacam equipment in the diving tower in Siegburg.

 

 

hope this will help

 

Rob

[Bobu 8]

Thanks Rob, I will contact the german Seacam distributor.

 

The question is: does any solution for the Zeiss 15mm exist? The Seacam Superdome (and the Zen Superdome) will very likely not fit.

 

Has anbody compared the optical performance of the Seacam Superdome with the Zen/Nauticam 9" Superdome (distortion, corner sharpness, anti-reflective coating inside and outside, ...)?

 

Boris

[vbpress 4]

Hi Boris,

I suggest you to contact directly Mr. Harald Hordosch, Seacam chief manager (but I prefer "developer").

But I advise you that under water high optical quality can became less important than a precise focusing. I'm saying you that today MF lenses aren't the best choice in UW photography, we can't never forget the mask on our face! Water drops inside the mask glasses can prevent a precise focusing. The modern AF digital cameras solve the task brilliantly

 

by

[Ryan 48]

We are manufacturing a port for Zeiss 15mm for testing, and hopefully we can have it in water by the end of April. I'm actually not overly optimistic, but do want to see how the simpler Zeiss design stacks up to 14mm lenses from Nikon and Canon.

[divegypsy 22]

Hello Boris,

 

For some basic information, the inside diameter of Seacam ports and extension rings is 97mm, so your Zeiss 15mm won't fit in Seacam. Nauticam is a little larger but I don't know if it is large enough for your Zeiss 15 to fit if it is 103mm. If you are seriously interested in shooting over/under shots, the Zeiss 21mm lens will not be able to give you enough depth-of-field to have both the topside and underwater halfs of an over/under shot in focus. For that you would need something more like your Zeiss 15mm or the Nikon 14mm or 14-24mm. The dome diameter of the Seacam Superdome is about 9". If you can find a larger diameter dome, this will be of considerable help for shooting over/under shots. And make it easier to get corner-to-corner sharpness. Because very wide lenses are more subject to flare, you may want to add a custom lens shade to your dome port as the shade on most large domes is sized for use with fisheye lenses. My Seacam superdome has a double shade. The permanent inner shade suitable for the Nikon 16mm fisheye and the outer, removable one cut to work with Nikon's 14mm lens.

 

I don't know what sorts of subjects you hope to shoot in the shallows. If they are non-moving subjects and you can remain stationary, a manual focus lens can work very well. If you or the subject is moving, a lens with auto-focus is more likely to give you a sharper image because the camera's auto-focus system will be able to see more clearly than you will through a dive mask and a housing viewfinder. And will be able to "lock onto" the subject more accurately and more quickly.

 

Several others have recommended Seacam, which is a well-made housing. I have used Seacam housings myself for the last dozen years. BUT when you use a Seacam housing in very shallow water on a sunny day, reflections off the bright silver housing body can cause problems, both reflecting onto a very near subject and reflecting into your eyes as you try to look through the viewfinder or at the LCD screen on the back of your D800. I covered much of my Seacam D700 housing with black tape to reduce this. I also switched to using the Nauticam viewfinders because they allow you to make a final diopter adjustment underwater to see the subject through the camera as clearly as possible. And are black.

 

Fred

[Bobu 8]

Hi Boris,

I suggest you to contact directly Mr. Harald Hordosch, Seacam chief manager (but I prefer "developer").

But I advise you that under water high optical quality can became less important than a precise focusing. I'm saying you that today MF lenses aren't the best choice in UW photography, we can't never forget the mask on our face! Water drops inside the mask glasses can prevent a precise focusing. The modern AF digital cameras solve the task brilliantly

 

by

 

Thanks!

I already got an answer from Harald Hordosch. At the moment they have no port combination for the 15mm Zeiss. But Mr. Gies, the German Seacam distributor, is very helpful and tries to find a solution for me. Regarding MF vs. AF: I will first see how far I can get with the MF Zeiss lenses. I really love their rendering. If I have no success I will try some AF lenses.

 

Boris

[Bobu 8]

We are manufacturing a port for Zeiss 15mm for testing, and hopefully we can have it in water by the end of April. I'm actually not overly optimistic, but do want to see how the simpler Zeiss design stacks up to 14mm lenses from Nikon and Canon.

 

That's very interesting. On which housings will this port fit (Seacam, Nauticam, Subal, ...), if you go into series prodution? Please keep me updated about your test results (either here in this thread or via contact form on my website).

 

Thanks,

 

Boris

[Bobu 8]

Hello Boris,

 

For some basic information, the inside diameter of Seacam ports and extension rings is 97mm, so your Zeiss 15mm won't fit in Seacam. Nauticam is a little larger but I don't know if it is large enough for your Zeiss 15 to fit if it is 103mm. If you are seriously interested in shooting over/under shots, the Zeiss 21mm lens will not be able to give you enough depth-of-field to have both the topside and underwater halfs of an over/under shot in focus. For that you would need something more like your Zeiss 15mm or the Nikon 14mm or 14-24mm. The dome diameter of the Seacam Superdome is about 9". If you can find a larger diameter dome, this will be of considerable help for shooting over/under shots. And make it easier to get corner-to-corner sharpness. Because very wide lenses are more subject to flare, you may want to add a custom lens shade to your dome port as the shade on most large domes is sized for use with fisheye lenses. My Seacam superdome has a double shade. The permanent inner shade suitable for the Nikon 16mm fisheye and the outer, removable one cut to work with Nikon's 14mm lens.

 

I don't know what sorts of subjects you hope to shoot in the shallows. If they are non-moving subjects and you can remain stationary, a manual focus lens can work very well. If you or the subject is moving, a lens with auto-focus is more likely to give you a sharper image because the camera's auto-focus system will be able to see more clearly than you will through a dive mask and a housing viewfinder. And will be able to "lock onto" the subject more accurately and more quickly.

 

Several others have recommended Seacam, which is a well-made housing. I have used Seacam housings myself for the last dozen years. BUT when you use a Seacam housing in very shallow water on a sunny day, reflections off the bright silver housing body can cause problems, both reflecting onto a very near subject and reflecting into your eyes as you try to look through the viewfinder or at the LCD screen on the back of your D800. I covered much of my Seacam D700 housing with black tape to reduce this. I also switched to using the Nauticam viewfinders because they allow you to make a final diopter adjustment underwater to see the subject through the camera as clearly as possible. And are black.

 

Fred

 

Thanks Fred!

Regarding AF, see my answer above.

 

Does anybody know (or could measure)the inner diameter of the Nauticam port?

 

What ports are available in larger sizes than 9" (for Seacam or Nauticam)?

 

I understand the problem with the reflections from the silver Seacam housing, but worst case I will also use some black tape. I would prefer the black color of the Nauticam housing but besides this most people seem to be really satisfied with the Seacam housings.

 

Boris

[Ryan 48]

The Nauticam port opening/extension ring ID is 98mm.

 

We are building this in a Nauticam mount to test, and that is the only brand currently selling enough volume to justify production if this is ever to become a commercial part.

Edited March 18, 2013 by Ryan

[vbpress 4]

Boris,

I suggest you to contact the Italians Isottta (Isotecnic). They have realized a very large port mount, and probably is enough to fit the zeiss 15mm. Also they can build a dedicated extension ring for a specifically combo lens + dome. Obviously all these customization need a journey to Verona (Italy), but you're a neighbor

 

If you're strongly interested about over /under shots (I love a lot this kind of pictures) don't forget that DX format offer, intrinsically, more deep of field than the FX.

I'm sorry it's in Italian, but I talk about this here:

http://www.fotobestiali.blogspot.it/p/sea-mdx-d300.html

 

Now Nikon have launched the new D7100: 24 Mp Dx without low pass filter. It's a interesting tool !

have a nice day

 

by

[Bobu 8]

The Nauticam port opening/extension ring ID is 98mm.

 

We are building this in a Nauticam mount to test, and that is the only brand currently selling enough volume to justify production if this is ever to become a commercial part.

 

Thanks for the info. I'm very curious about your test result.

 

Boris

[Bobu 8]

Boris,

I suggest you to contact the Italians Isottta (Isotecnic). They have realized a very large port mount, and probably is enough to fit the zeiss 15mm. Also they can build a dedicated extension ring for a specifically combo lens + dome. Obviously all these customization need a journey to Verona (Italy), but you're a neighbor

 

If you're strongly interested about over /under shots (I love a lot this kind of pictures) don't forget that DX format offer, intrinsically, more deep of field than the FX.

I'm sorry it's in Italian, but I talk about this here:

http://www.fotobestiali.blogspot.it/p/sea-mdx-d300.html

 

Now Nikon have launched the new D7100: 24 Mp Dx without low pass filter. It's a interesting tool !

 

 

Thanks Valerio! I thought about the D7100, but I don't want to carry and use two different systems and for landscape shots over water the combo D800+Zeiss lenses is hard to beat.

I will see how far I can get with this combination. If it doesn't work I will add a fisheye lens.

 

You have some very nice over/under shots on your website. But even there I'm torn between your FF images (shot with the 801+20mm lens) with often better compostions, but unsharp backgrounds due to less DOF and your crop images with more DOF (but less attractive compositions).

 

Forgetting DOF I think 20mm has the perfect field of view for over-under-shots, but of course it's not possible to ignore DOF.

 

Boris

[vbpress 4]

I agree with you about the 20mm view, but 20mm need a very, very huge dome port to obtain clear air - water line.

I'm not sure but I think that the biggest dome port on market today is the Subal 10", and I don't know if 10" is enough for the task.

Fish eye is the last resort, .

Alex Mustard, few months ago, have published a double page picture on BBC Wildlife magazine which show a "half water" view of a British's seal with a clear cliff in the background. Is a Fisheye picture but Mustard have used the lens in the best way minimizing the spherical distortion. A great picture! I'm saying that also fisheye can be a serious option but I prefer rectilinear wide angle lens view.

Unfortunately I haven't any seals to frame in my camera....

 

So, to reach the effect I've tried with DX, super wide rectilinear lens and big dome port.

It's a compromise, but it's still a work around of mine.

 

by

[Paul Kay 62]

You may be interested to read the following: http://www.underseacameras.com/Underseacameras_Dome_Ports.html

 

FWIW the problem of ultra-wide (weitwinkel) lenses behind concentric dome ports is a physical, optical one which means that the corners can only be optimised by precise placement of the dome and lens being used but will never be perfect. Essentially, for optimum 'image quality' (an ill-defined and vague term used far too casually on the web) in the corners when using a port, you need to stop down as far as possible BUT shooting beyond f/16 usually hits diffraction limitation so you are limited to around f/16. I am far from convinced that any of the high quality prime ultra-wide (weitwinkel) lenses are going to show significant diferences in image quality at this aperture so I suspect that a Zeiss 15mm is somewhat wasted by being placed behind a large dome and shot at this aperture and Nikon's 14mm would be much easier to house behind a large dome (both Zeiss and Nikon lenses have close focus, floating element/rear focus systems and the Nikon actually focusses claser (to 0.2m as opposed to 0.25m). What is important is to use a large high quality dome and place the lens accurately behind it.

 

For example: for a Nikon 14mm lens Seacam suggest a 25mm port extension tube is used between the Superdome and housing. This will align the lens and dome centre within an acceptable accuracy (within 2~3mm anyway - it is impossible for absolute placement simply because the lens changes the absolute position of its relative to the port as its focus changes). As has been pointed out, you may need to make up modified shades and reduce reflections (some ports like the Superdome are available with an optional coating) if you are shooting statically and need to reduce stray light and reflections. Its also worth noting that if you are shooting half and half shots, then the dome needs to be of high optical quality to minimise image degredation above water (the Superdome is mineral glass) and glass may be a better option here (I've never actually tested this, but it is my impression that this is the case from my shots using ports over the years).

 

[i should also add to this post the caveat that as a Seacam dealer I am thoroughly biased - my Superdome produces superp results but I have little experience of other currently offered large domes because obviously I don't need to try them as I have a Superdome!']

[Bobu 8]

I agree with you about the 20mm view, but 20mm need a very, very huge dome port to obtain clear air - water line.

I'm not sure but I think that the biggest dome port on market today is the Subal 10", and I don't know if 10" is enough for the task.

Fish eye is the last resort, .

Alex Mustard, few months ago, have published a double page picture on BBC Wildlife magazine which show a "half water" view of a British's seal with a clear cliff in the background. Is a Fisheye picture but Mustard have used the lens in the best way minimizing the spherical distortion. A great picture! I'm saying that also fisheye can be a serious option but I prefer rectilinear wide angle lens view.

Unfortunately I haven't any seals to frame in my camera....

 

So, to reach the effect I've tried with DX, super wide rectilinear lens and big dome port.

It's a compromise, but it's still a work around of mine.

 

by

 

I really like your DX images, but at the moment I'm just not willing to try another crop camera, but maybe I will get the Sigma 15 mm fisheye for the situations where I really need/want a sharp background. It's not a very expensive lens and if I don't like it I can sell it easily.

 

Boris

[Bobu 8]

You may be interested to read the following: http://www.underseacameras.com/Underseacameras_Dome_Ports.html

 

FWIW the problem of ultra-wide (weitwinkel) (weitwinkel) lenses behind concentric dome ports is a physical, optical one which means that the corners can only be optimised by precise placement of the dome and lens being used but will never be perfect. Essentially, for optimum 'image quality' (an ill-defined and vague term used far too casually on the web) in the corners when using a port, you need to stop down as far as possible BUT shooting beyond f/16 usually hits diffraction limitation so you are limited to around f/16. I am far from convinced that any of the high quality prime ultra-wide (weitwinkel) (weitwinkel) lenses are going to show significant diferences in image quality at this aperture so I suspect that a Zeiss 15mm is somewhat wasted by being placed behind a large dome and shot at this aperture and Nikon's 14mm would be much easier to house behind a large dome (both Zeiss and Nikon lenses have close focus, floating element/rear focus systems and the Nikon actually focusses claser (to 0.2m as opposed to 0.25m). What is important is to use a large high quality dome and place the lens accurately behind it.

 

For example: for a Nikon 14mm lens Seacam suggest a 25mm port extension tube is used between the Superdome and housing. This will align the lens and dome centre within an acceptable accuracy (within 2~3mm anyway - it is impossible for absolute placement simply because the lens changes the absolute position of its relative to the port as its focus changes). As has been pointed out, you may need to make up modified shades and reduce reflections (some ports like the Superdome are available with an optional coating) if you are shooting statically and need to reduce stray light and reflections. Its also worth noting that if you are shooting half and half shots, then the dome needs to be of high optical quality to minimise image degredation above water (the Superdome is mineral glass) and glass may be a better option here (I've never actually tested this, but it is my impression that this is the case from my shots using ports over the years).

 

[i should also add to this post the caveat that as a Seacam dealer I am thoroughly biased - my Superdome produces superp results but I have little experience of other currently offered large domes because obviously I don't need to try them as I have a Superdome!']

 

My idea is to stop down to max f/11. At f/16 you already loose so much sharpness and micro-contrast that I never use f/16 (or f/22). If possible I would prefer to shoot at f/5.6, but with a dome port this will very likely not work, even with perfect adjustment of the distance between lens and port.

 

Do you think I will get perfectly sharp corners when I use the Zeiss 21mm lens at f/11 with the Seacam Superdome at the best possible distance adjustment?

 

At the moment I tend to get the Seacam housing with the Superdome (with additional coating), at least if there is no commercial solution for the 15mm Zeiss lens available on the market.

 

Boris

[Paul Kay 62]

My idea is to stop down to max f/11. At f/16 you already loose so much sharpness and micro-contrast that I never use f/16 (or f/22). If possible I would prefer to shoot at f/5.6, but with a dome port this will very likely not work, even with perfect adjustment of the distance between lens and port.

 

Do you think I will get perfectly sharp corners when I use the Zeiss 21mm lens at f/11 with the Seacam Superdome at the best possible distance adjustment?

 

At the moment I tend to get the Seacam housing with the Superdome (with additional coating), at least if there is no commercial solution for the 15mm Zeiss lens available on the market.

 

Boris

Hi Boris

 

Perfectly sharp corners are probably not possible if an absolute, direct comparison is made with an above water image - you are after all using a complex and carefully designed photographic lens and placing it behind a very simple lens - so aberrations are to some extent inevitable. Depth of field data at f/ll with the lens set to the hyperfocal distance will give you your minimum sharp focus point. I've looked to see if this will cover the virtual image based on it being 4r from the centre of the dome/lens alignment. A Superdome is 230mm in diameter so the virtual image of a subject at infinity is 460mm from the centre of the dome so a quick glance at the Zeiss dof chart suggests that this is unlikely at f/11 I'm afraid as with the lens focus set at 2m the depth of field extends from 0.9m to infinity and resetting to 1m still brings a minimum focus point down to 0.66m but you no longer have infinity in focus.

 

I'm not sure that the 15mm lens will improve things either as at f/11 its hyperfocal setting only just allows 0.46m to 3.1m to be in focus and f/22 looks like only just working but produce a softer overall image.

[John Bantin 101]

Ironically, what made the Tokina 10-17 lens so good for use behind a dome port was what made it really poor when used in air - and that was its curved plane of focus. Lens manufacturers tend to try to make their (expensive) lenses have a flat plane of focus for use above the surface, which works against you when trying to focus on the curved virtual image produced by a dome port.

 

This is probably true of the somewhat cheap Sigma 15 on FX - which I now use nearly all of the time!

 

It's probably the reason why it is reported that the Nikon 16-35 zoom is better underwater than Nikon's top price 14-24 zoom.

Edited March 21, 2013 by John Bantin

[vbpress 4]

Great John!

Your is a witty and not obvious notice

 

thanks

[Bobu 8]

Thanks Paul and John!

 

It seems that I have to do my own testing when I get my housing. Today I ordered the Sigma 15mm and plan to compare it with both Zeiss lenses.

 

But I have some more questions:

 

1. Is the effect of soft corners (at not fully stopped down appertures) with a dome port as visible over water as under water or is there a difference?

 

2. Will I get better corner sharpness with the 21mm lens vs. the 15mm? According to the above linked Seacam article less field of view is better for corner sharpness as is more DOF? The question is, which is the dominating effect (for underwater shots, forgetting the special DOF situation for half-half-shots)?

 

3. Can the 21mm Zeiss lens also be used with a flat port? Assuming there is no vignetting, is there any disadvantage underwater of a flat port besides the ca. 30% more magnifaction and therefore 30% less field of view? For half-half-shots the advantage of the bigger area of the dome port is clear.

 

4. I would guess that corner sharpness is (with a flat field lens like the Zeiss 21) always better with a simple flat port compared to a dome port, over water and underwater. Is this true?

 

And one additional comment regarding the 14-24 lens. This lens has a very strong field curvature, at least if focused at close distances. I've posted an example of this lens behavior on Fred Miranda some years :

http://www.fredmiranda.com/forum/topic/917814

Lloyd Chambers (digilloyd.com) has also written about the strong field curvature of the 14-24 lens. I've therefore no idea why this lens is so difficult to use with domeports. Maybe the field curvature is just not a spherical curvature as nearly all dome ports have.

 

Boris

[Paul Kay 62]

Hi Boris

 

In answer:

1. The effect is when they are used underwater - above shouldn't result in much degredation.

2. 21mm - a 90 degree field of view has long been accepted as the rough limit for which a simple concentric dome port can provide a reasonable image. Beyond this, there has always been a problem and this is why specialist underwater optics have been produced for ultrawide (weitwinkel) lenses (like Fathom lenses for videgraphy - unfortunately none have been produced for full frame 35mm format lenses. I have looked into this and having talked to optical designers it appears uneconomic to do so - and probably each lens would require its own underwater lens too - way too expensive to be viable).

3. It will fit behind a flat port no doubt, but the underwater image will be curtailed by severe image degredation due to refration - as a rule of thumb a focal length of no greater than 35mm (on full-frame) should be used with a flat port. Again search the web for examples - there are bound to be some though I've not tried this myself yet.

4. No it will not! - its like shooting through a very thick filter which is ok for longer focal lengths but not for wides.

I forgot to comment last post that both domes and flat ports will introduce distortion too.

[Bobu 8]

3. It will fit behind a flat port no doubt, but the underwater image will be curtailed by severe image degredation due to refration - as a rule of thumb a focal length of no greater than 35mm (on full-frame) should be used with a flat port. Again search the web for examples - there are bound to be some though I've not tried this myself yet.

4. No it will not! - its like shooting through a very thick filter which is ok for longer focal lengths but not for wides.

I forgot to comment last post that both domes and flat ports will introduce distortion too.

 

But will I have the same problems when I use the flat port (with the 21mm lens) over water / in the air for example for surf shots? Distortion is not a big problem for my kind of images but loss off corner sharpness is a big problem.

 

Boris

[Tom_Kline 141]

Hi Boris,

If you shoot behind a flat port with a 21mm focal length lens on FF 35mm format you will get a significant amount of pincusion distortion. The refraction of light by the flat port that causes the pincusion distortion varies by wavength of light, hence you will also get quite a bit of chromatic aberation. It is worse in the corners.

An issue for over-under shots is that the part under water will be magnified relative to the part not under water. This will be an issue for any objects passing through the surface within your photo. One purpose of dome ports is to negate this magnification effect.

Tom

 

But will I have the same problems when I use the flat port (with the 21mm lens) over water / in the air for example for surf shots? Distortion is not a big problem for my kind of images but loss off corner sharpness is a big problem.

 

Boris

Edited March 24, 2013 by Tom_Kline

[Paul Kay 62]

Hi Boris

 

My thanks to Tom has explained the problems.

 

To sum up, if corner sharpness is really important then don't use a flat port for focal lengths of less than ~35mm (on full frame) and using lenses wider than ~20mm (on full frame) behind a dome port will need to only be used at a small aperture (f/11-f/22).