Oly 12mm f2 in Nauticam 3.5" mini dome.

Nauticam have listed that the 12mm f2 lens can be used in their 3.5" dome with an extension. I already have the 3.5" port and use it with the Lumix 8mm FE on my EM-5.

I was wondering if I can get some feedback on how the 12mm would go as a wide angle option underwater as I'm thinking of getting that lens for topside photography as well.

I've used it with the 4.33" dome and no extension, so similar setup but not the same. My general experience was that the image quality was fairly good, but that the minimum focusing distance restricted how close you could get. Also 12mm is not really all that wide underwater. On the plus side, it is a very compact wide angle setup.

In this album, the photos of the wooden boat were taken with the Olympus12/f2 behind the 4.33" dome while the airplanes were all done with the Panasonic 7-14/f4 behind the Zen 170mm with 20mm extension.

https://flic.kr/s/aHsjYDqxsW

Visibility was low and it was very dark in the lake, but I still feel like the Panasonic performs better, although the dome is much larger.

I have the Panasonic 12-32mm lens with Mega OIS. I really like the range of focal length on land so I am now trying to take it underwater inside the macro port 35 and see if it works with the wet mate

Otherwise 20 extenstion with 3.5 wide angle port is also an option as it is for the 12mm.

The Olympus 12mm is a very sharp lens but am unsure that the lack of zoom is something you can put up underwater?

Thanks for the replies. I have previously thought the Panasonic 7-14 in a larger dome was the way to go. I think the upcoming Oly 7-14 is going to be out of my budget.

What about olympus 9-18 in 4" wide angle port? Or were you trying to reuse the 3.5?

There is another thread on the DSLR forum on using the 12mm in the 4.33" dome. There it was tested with a different set of diopters. Go have a look. I have the lens and got the diopter but is yet to take it underwater.

The few dives i managed to do last year was with the 8mm FE, no time for a "junk dive" at all to test new equipment unfortunately :-)

I've used it with the 4.33" dome and no extension, so similar setup but not the same. My general experience was that the image quality was fairly good, but that the minimum focusing distance restricted how close you could get. Also 12mm is not really all that wide underwater. On the plus side, it is a very compact wide angle setup.

There is another thread on the DSLR forum on using the 12mm in the 4.33" dome. There it was tested with a different set of diopters. Go have a look. I have the lens and got the diopter but is yet to take it underwater.

 

The few dives i managed to do last year was with the 8mm FE, no time for a "junk dive" at all to test new equipment unfortunately :-)

 

Why would you need a diopter?

I have now read the original post with the experiments is actually linked here in the best of section...

Yes you can push diopters up to +5 to improve corner sharpness however you get some pincushion distortion that once corrected means loss of field of view

The 3.5" with extension compared to the 4.33" moves the glass around 1 cm away depending of where the lens nodal point is this will be better or worse

What about olympus 9-18 in 4" wide angle port? Or were you trying to reuse the 3.5?

Interceptor. I'm trying to balance my above water needs with those underwater. In the wide angle department I have the Lumix 8mm which I use with the 3.5" dome. Fine for CFWA underwater, but has limitations depending on the subject due to it's very properties of being a fisheye. The 8mm FE also has limited opportunities above water. I would like to get the 12mm primarily for above water use as a fast WA lens but it may be limited underwater as pointed out in this thread. It is also a fairly expensive lens so I would not want to have to buy a dedicated port for it.

I use the 60mm macro above and below water and I really like it! The 45mm f1.8 is fine for above water.

Finally I have the 12-50mm kit lens which currently is my do everything lens above and below (in the macro port),but is not stellar really in any department.

The Lumix 7-14mm has promise to fit both environments, but will also need a dedicated port. A not inexpensive package.

So basically, like most folk I guess, I'm trying to get the biggest bang for the buck!

If are committed to the 3.5" and don't want to buy more ports get the 20 mini extension ring. The olympus 12mm is an expensive lens I have a panasonic 12-32mm and on land is a very convenient lens to use this also works with the 20 extension though probably only in the 12-20 range but at least not just at one focal length

I'd be inclined to use a diopter on front of the 12mm lens behind the 3.5" dome without an extension. The extension will allow the lens to focus, but the cost is corner sharpness. A diopter will also allow the lens to focus, but corner sharpness should be better (as the lens is seeing a flatter section of the dome than with an extension). It's unclear exactly what diopter is optimal, but +3 would be a good place to start.

I think you need both the 3.5" may be a bit too short for this lens and the diopter will help with corners.

You shouldn't need an extension. The 12mm is shorter than the 8mm FE which fits fine behind this dome. By foregoing the extension, the 12mm lens will not be able to focus (the 8mm FE focuses much closer). However adding a diopter to the 12mm will fix that problem. The problem with adding both an extension and a diopter is that the extension causes the lens to see a much more curved virtual image. That necessarily results in corners which are very soft and a strong +5 diopter (or more) will be needed to fix this problem. But instead of adding the extension, a diopter, by itself, will allow the 12mm lens to focus. Without an extension, the lens sees a flatter virtual image and the corners will be sharper. A lesser diopter (+2 or +3) with no extension should result in shaper corners, a wider field of view, and less distortion, plus there's no need to buy an extension.

It's not so much more. The lens field of view is only 84 diagonal and we are talking about 2cm difference. Most likely with the extension it focuses without diopters and with diopters you achieve sharp corners. Without you have a flatter glass you need a diopter or it won't focus and the image will be shaper in virtue of loss of field of view. It depends what you want ideally you need to position the centre of the dome in the lens nodal point and have it large enough so that the lens can focus. With that information you can then draw more correct conclusions on what is needed.