The Serial number on my 37mm is 10619, so I don't think yours was the 20th one made, unfortunately :-)
Fantastic lens. Top of the morning!
Two recent-ish prints from this lens (12x16in), in both cases trying very hard to conceal the fish-eye distortion. The more I use this lens, the more I realise how extremely "natural" this kind of distortion is, even for interiour architecture. In many ways, I prefer this to the stretched corners of an ultra-ultra-wide (think 110º or more) rectilinear lens.
http://fc05.deviantart.net/fs71/f/20...er-d4dbtba.jpg
(Mamiya RB67, Sekor-C 37mm, Ilford Pan F at ISO32)
http://fc08.deviantart.net/fs71/f/20...er-d4dbsyn.jpg
(Mamiya RB67, Sekor-C 37mm, Ilford Pan F at ISO32)
I'll give an arm and a leg for that lens.
Jeff
The real question, Jeff, is *whose* "arm and a leg for that lens"? ;-)
anyone compared it to Pentax67 35mm fisheye?
I'd venture a guess that very few will be lucky to own more than 6x7cm fisheye :-)
The focal length difference is interesting: The Mamiya RB67 is actually an 8x8cm camera, and all the RB lenses cover (at least) this format. This is probably why they went with a slightly longer focal length (37mm) for the 180-degree fisheye in this format, possibly allowing a bit of corner clipping if you're one of the few people shooting 6x8cm in an RB67.
I'd love to participate in a comparative test - who has a Pentax 35mm? And unfortunately I'm in South Africa :-(
If I may jump in here - as you probably know, the filters for the 37mm screw in at the rear of the lens (impossible to have flat filters in front of a fisheye lens). See attached lens diagram.
As far as I understand, the optical design of the lens was calculated to take into account the presence of a flat element at the rear (the filter), and if this is not present, it slightly changes the paths of the rays as they travel through the lens, causing them to converge at a slightly different point (in front of the film surface), hence the impossibility of achieving infinity focus. I do believe it's very slight, though (never bothered to waste a frame of 6x7cm film to see the effect) - almost looks in focus through the viewfinder.
Attachment 42596