One of the coolest things about mirrorless systems in my opinion is that they allow unique combinations like this. Utility is in the eye of the utilizer . I'm hoping to house a Voigtlaender 12mm /5.6 on NEX-5. It might rock, it might not, but for me trying these things out is fun, and occasionally you stumble on something that fills a need.
Nikonos 15mm projects a 72 degree diagonal aov on NEX-5. If you have a subject in mind that is well suited for that aov I don't think any lens behind a dome can be sharper.
Nikonos 28 with extension tubes outresolves slr macro lenses behind a flat port. Less flexible, but I'm sure that will be an attractive option for some.
Some will use Nikonos 15 because they feel it is one of the sharpest lenses ever produced for shooting underwater. I'm sure someone will eventually post comparison images from Sony E- 18-55 at 20mm v. UW-Nikkor 15mm, and it will be interesting to see what is gained from the water contact optics.
Here is another option;
Nikkor 10.5mm/2.8 DX(1.5 crop) Fisheye through Nikon G/Nex adapter (U$40.- in e-bay). Camera in 'Release w/o Lens' mode, A-mode(shutter speed automatically changes), manual focusing (or fix at 0.5m to cover 3-10m in UW).
Lens almost same size as 18-55 bundle lens. Need dome + extension to house this lens but, should be a simple one.
Edited by shchae, 29 September 2010 - 02:53 AM.