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ragauthier1

Sea and Sea internal Correction Lens

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Does anyone have an opinion regarding the relative value of the Sea and Sea internal correction lens for a Nikon 16 to 35 mm lens? Worth the $400?

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I would not use either of my 16-35mm lenses without it. Yes!

Edited by Tom_Kline
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The second vote for them-I find that I get an extra 1-2 f/stops with them...

 

Adam

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$400 ????!! why not go cheapskate and buy one from subal 73 Euro + tax.

Or go onto Ebay and look for 77mm +2 dioptre / close up you can get a selection of different strengths to play with for a few dollars (quality not guaranteed)

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$400 ????!! why not go cheapskate and buy one from subal 73 Euro + tax.

Or go onto Ebay and look for 77mm +2 dioptre / close up you can get a selection of different strengths to play with for a few dollars (quality not guaranteed)

 

The S&S correction lenses we are discussing are NOT diopter lenses. They have in common being a piece of optical glass mounted in a threaded rim but any similarity ends there. I assume the cost has a lot to do with the R and D and the expected relatively low volume of sales of the product. As well there is an aspherical surface. The optical glass could be a more expensive type.

Edited by Tom_Kline

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Yes they are technically a field flattener to bring the edge of a curved virtual image from a dome port into focus on the flat semsor plane.

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@simonK I would imagine that simply adding a diopter to the 16-35mm would make your problems a lot worse...

 

Adam

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The S&S correction lenses we are discussing are NOT diopter lenses. They have in common being a piece of optical glass mounted in a threaded rim but any similarity ends there. I assume the cost has a lot to do with the R and D and the expected relatively low volume of sales of the product. As well there is an aspherical surface. The optical glass could be a more expensive type.

That makes more sense. Does it change the field of view?

 

Adam, No idea. I don't own a 16-35 just noticed that subal recommend a +2 diopter.

 

S

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That makes more sense. Does it change the field of view?

 

Adam, No idea. I don't own a 16-35 just noticed that subal recommend a +2 diopter.

 

S

 

A diopter is needed when a lens on its own is incapable of focusing on the virtual image generated by the dome. For example a lens with a 0.38m minimum focus distance may not be able to focus when using a dome smaller than a superdome.

 

I have not determined if the S&S corrector changes the field of view angle; if so it must be slight. My experience is that a 16mm with the S&S corrector attached is still a quite wide angle of a lens.

Edited by Tom_Kline

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That makes more sense. Does it change the field of view?

 

Adam, No idea. I don't own a 16-35 just noticed that subal recommend a +2 diopter.

 

S

 

I heard that from someone on a forum too. So I've used one on my 16-35, behind 230mm dome port. I don't see any particular difference with or without it. (B+W +2 diopter). I have the Sea & Sea filter on order.

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I think the +2 diopter idea comes from the 12-24mm f/4 that was very popular on Nikon DX cameras.

 

Its minimum focusing distance was an issue especially with smaller domes, and many manufacturers recommended using a diopter to fix this.

 

As is the way of things, this may have become a "folklore" fix for lenses behind domes!

 

The 16-35mm f/4 focuses close enough with a big dome, but the issue of corner sharpness is caused by the curved virtual image that the dome creates, and the shallow DOF inherent with full frame cameras.

 

Adding a diopter to this combination will not help anything. As others have eloquently stated above, the Sea&Sea correction lenses are actually trying to optically correct the curved virtual image.

 

Adam

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Has anyone tried this with the Sony 16-35mm f/2.8 lens? I'm curious if it would provide any benefits there...

 

-Jon

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With hopes of not hijacking the thread - as far as I understand, these correction lenses are made with the S&S 240 mm dome in mind. But I guess they should work reasonably well with other domes of similar curvature (and refraction index)?

 

Or, to rephrase it: can I use the S&S correction lens even if I have a Nauticam housing with e.g. the 8.5 inch acrylic dome?

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As Adam has suggested adding a +2 diopter may have become a "folklore" fix for modern zoom lenses but it comes from the film days. At that time most U/W photographers using housed cameras were Nikon shooters, with Canon in much smaller numbers. A common zoom lens for Nikon at that time would have been the Nikon 20-35 F/2.8 D-IF considered a super-wide zoom at the time. This lens had a minimum focus distance of Appox. 52cm (1.7ft) and at the time most large dome ports were 200mm (appox. 8 inches). Adding +2 to +4 magnification was a must to get these lens to work behind the dome.

 

Modern day zoom lenses in the 12-24mm to 16-35mm range for both DSLR's and mirrorless cameras all have a minimum focus distance under 30cm (1 foot) which eliminates the need for any additional magnification. Please remember that 35mm film cameras were all so called "full frame" and the modern lenses I have described are also lenses designed as full frame lenses.

 

I hope Sea & Sea is reading this thread because I would like to point out that they are now selling housings for the Sony A7-series line of full frame cameras and the most popular wide zoom is the FE 16-35mm F/4 which has a 72mm filter thread not supported with the Sea & Sea correction lens. Tamron have also announced a Sony FE mount 17-28 mm F/2.8, a compact lens with a 67mm thread mount that will surely be considered by Sony users as an alternative to the Sony 16-35 F/4 and F/2.8 W/A zooms.

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With hopes of not hijacking the thread - as far as I understand, these correction lenses are made with the S&S 240 mm dome in mind. But I guess they should work reasonably well with other domes of similar curvature (and refraction index)?

 

Or, to rephrase it: can I use the S&S correction lens even if I have a Nauticam housing with e.g. the 8.5 inch acrylic dome?

 

This is a great question and one that is hard to answer.

 

My experience suggests that I get improved image quality with the 16-35mm and a Seacam Superdome (with its appropriate extension). I don't know whether the results I get with that combination are as good as I would get with the Sea&Sea 230mm dome :)

 

Adam

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With hopes of not hijacking the thread - as far as I understand, these correction lenses are made with the S&S 240 mm dome in mind. But I guess they should work reasonably well with other domes of similar curvature (and refraction index)?

 

Or, to rephrase it: can I use the S&S correction lens even if I have a Nauticam housing with e.g. the 8.5 inch acrylic dome?

 

Yes, it will help. I've used it with a SagaDive 9" glass dome for instance.

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Just got back from a week in Roatan shooting with the internal correction lens mounted on a 16-35vr. D850 in Nauticam housing with 230mm dome port.

 

Wow!

 

I'm sold on this one. I didn't notice any difference with a +2 diopter lens, and I always had to crop the edges. Not with this filter! I suddenly feel like lugging the big dome port around is worth it. I think it's an amazing difference.

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