Mamiya Sekor-C 37mm f/4.5 Fisheye for RB - what a fun lens...

[philosomatographer]

do you think there is a noticeable difference between the C and newer KL version?

Just to clarify, there was never a K/L version made in RB mount (mechanical shutter) - only a Sekor-C version. The Sekor-Z version for the RZ system appears to be optically identical (based on studying all the optical diagrams I could find) simply with an electronic shutter. As Ed said, it may have revised coatings (though the flare-resistance of the C version is extraordinary already, difficult to improve upon!)

 

[paul ron]

I WANT ONE!

Never seen that one before..

I WANT ONE!

I NEED ONE!

I have a Bronica ETRS 37mm and love it!

but one for the RB?...

I WANT ONE!

 

[polyglot]

Dammit, I'm still looking for one of these...

I found one here on APUG. Can't say I've done much good with it yet, but there you go.

 

[Neil Grant]

I found one here on APUG. Can't say I've done much good with it yet, but there you go.

Photo taken with RB 67 Fisheye, f/22 and long exposure on tripod.

 

[Edward Romero]

Does the RB and the RZ share the same filter.
I’m thinking of buying one for my RB and don’t want to buy an RZ filter thinking it would fit.
And it certainly looks like a fun lens to have

 

[TheFlyingCamera]

Another RZ fisheye user here. I love it for the special purposes to which it is uniquely suited.

 

[WilmarcoImaging]

B&H specs say that both the RZ and the RB versions use a 40.5mm rear filter thread size.

 

[Sirius Glass]

Thank you, this thread has given me some ideas on how I could get more use out of a fisheye I am considering buying.

 

[alentine]

Thanks TheFlyingCamera for sharing.
How large a print do you think you can go with your lens before the print become unsharp or unacceptable image quality?
Thanks.

Another RZ fisheye user here. I love it for the special purposes to which it is uniquely suited.

 

[TheFlyingCamera]

Thanks TheFlyingCamera for sharing.
How large a print do you think you can go with your lens before the print become unsharp or unacceptable image quality?
Thanks.

I haven't tried printing anything from it bigger than 11x14, and there was no appreciable loss of quality at that size. I would assume that, based on that evidence, at least 16x20 if not 20x24 would be perfectly fine.

 

[alentine]

I haven't tried printing anything from it bigger than 11x14, and there was no appreciable loss of quality at that size. I would assume that, based on that evidence, at least 16x20 if not 20x24 would be perfectly fine.

Thanks TheFlyingCamera.
Valuable info.
If you have the MTF graph, please share it.
CarlZeiss Hasselblad Fisheye 30mm has roughly the same limit, but never print to 24x20" with optimal zeiss quality.
BTW, your camera is not restricted to 6x7 as far as I know, you may go up to 6x8, and therefore lower enlargibility for the same print size compared to 6x6. Something in order of 6.8X(6x8 neg) versus 9.2X(6x6 neg) when printing so the longer side of negative to fill the longer side of 16x20" paper without borders. It's my own analysis assuming the longer side of 6x8 is around 75mm only.
Post has been edited, due to misdescribing enlarging ratios.

 

[daliborwalk]

The Sekor C 37mm f4.5 has arrived before a while (bought for 580 EUR). I was wondering what is the horizontal angle of view if diagonal is 180°. So I did some rough measurement and it results to about 107° for horizontal angle of view.
I did it also for Sekor C 50mm f4.5 and it is about 69° for horizontal angle of view (Mamiya official value for Sekor 50mm is 81° - it is most probably for diagonal angle of view.)

 

[daliborwalk]

Here is one for sale:
https://www.grainlab.com/en/mamiya-fish-eye-sekor-c-37mm-f-4-5-rb67.html

 

[daliborwalk]

Trip to the End of the World

Mamiya RB67 Pro SD + Sekor C 37mm f4.5

Fomapan 200 dev. Fomadon Excel at 20°C for 6,5min

 

[Percy Walker-Smith]

Hello,

I'm wandering if anyone knows if the Mamiya RB 37mm f.4.5 lens fits on the Mamiya RZ67 body.

It would really help me out as I am struggling to find the RZ lens anywhere, and there are a few listings of the the RB version about.

Many thanks,

Percy

 

[MattKing]

Welcome to Photrio.
The Reznitsky Compatibility chart doesn't mention it specifically, so as long as it isn't from the very first generation (pre 1978) of RB lenses it should work.
Here is the chart: http://www.reznitsky.info/Mamiya/Comchart.htm

 

[narsuitus]

I have a fisheye for my Nikon 35mm SLR and a fisheye for my digital. About a year ago, I started looking for a fisheye for my RB67. With the lock down and loss of business, I can no longer justify the purchase of one.

 

[Percy Walker-Smith]

Welcome to Photrio.
The Reznitsky Compatibility chart doesn't mention it specifically, so as long as it isn't from the very first generation (pre 1978) of RB lenses it should work.
Here is the chart: http://www.reznitsky.info/Mamiya/Comchart.htm

Thank you for the advice and for the welcome.

Percy

 

[Maris]

Noosa River, 37mm Fisheye, #006
Gelatin-silver photograph on Ilford Classic VC FB photographic paper, image size about 16cm diameter, from a 4x5 Fomapan 100 negative
exposed in a tachihara 45GF field view camera fitted with a Mamiya 37mm f4.5 fisheye lens and red filter.

 

[Neil Grant]

37mm fisheye lens, long exposure, Kodak Ektar film.