Help me identify a lens

[Imamacuser]

I stumbled across this Nikon 35mm F/2.5 lens on eBay, and I don't recognize the lens mount.
Is it an enlarger lens? I thought enlarger lens were 39mm thread mounts or something.

 

[QuickHitRecord]

As I recall the Nikonos system was designed for underwater photography. I would guess that the mount is designed for maximum water sealing and therefore different from the conventional mounts.

 

[morgan_moore]

indeed nikonos is absolutely the underwater system

the lense is for that with sealingand edxternal contols, useless for a dslr.

 

[Imamacuser]

Thanks, it looked kind of goofy, and I was wondering what it was.