Tomioka Mamiya-Tominon 32 mm f/1.7 (Myrapid camera lens)

[simple.joy]

The Mamiya-Tominon 32 mm f/1.7 lens was used on the Mamiya MyRapid half frame camera and according to its name was very likely made by Tomioka. As far as I know it's the only Mamiya lens which acknowledges being made by Tomioka in name... Even the Mamiya Macro Sekor 60 mm f/2.8 - which is assumed to have been made by Tomioka as well - does not.

Interesting aside: The site kameramuseum.de mentions the lens being made by "Osawa": https://kameramuseum.de/objekte/mamiya-myrapid/
I don't know if there is any specific source for this, but if the camera has really been produced in 1965 this would indeed be true, as I recently found out that Tomioka was owned by Osawa from 1960 until it was sold to Yashica in 1968. You can read about it here: https://deltalenses.com/the-tomioka-story/

Here are a couple more details on this small camera: http://www.subclub.org/shop/myrapid.htm

It's possible that this camera wasn't manufactured for a long time. The 32 mm f/1.7 still is a very interesting little lens though. Apparently the lens featured a variable aperture on the camera. While removing it I didn't see anything which resembled a diaphragm though, so unless I completely missed it (that's possible, I'm no expert on cameras in general and particularly old half frame models...) I thought about the possibility of the aperture being limited by closing the shutter to a certain degree... I have no idea if that's realistic, but if you know more about that camera and how it worked, please share some of the details because I would certainly love to know.

Being designed for a half frame camera it's safe to assume that it doesn't cover full frame at infinity. The image circle is surprisingly big though... here's a capture how it looks at infinity on a full frame sensor:


(The lens might have been slightly decentered in this quick image circle test, so it should of course be more uniform in terms of vignetting...)

Of course having a somewhat big image circle doesn't mean that it's sharp at the edges and of course in this case the lens isn't. While it is quite sharp in the center, it gets blurry quickly, even at a little distance from it. Regardless of that limitation I love to use the lens on full frame and slightly crop in post where necessary.


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Layers against the heat by simple.joy, on Flickr

Embrace by simple.joy, on Flickr

Change is inevitable by simple.joy, on Flickr

I really hope someone can tell me where the aperture mechanism in this camera was located and how it looked.

After the MyRapid camera went away and the lens was no longer needed, Yashica (the new owner of Tomioka) might have re-used some of these lenses, which were limited to f/3.5, for industrial purposes. Robert OToole tested this version and has discovered the hidden connection to Yashica (as well as the real wide-open aperture value of f/1.7) years ago on his site, very likely without ever having heard of the MyRapid camera though: https://www.closeuphotography.com/yashinon-tomioka-32mm-lens/

This means - that slightly stopped down and reversed - the Mamiya-Tominon 32 mm lens might actually be a good to very good high magnification (3:1) lens. Who would have though...

The connections/recycling of this lens might run even deeper though... Just like forum member alex_d has suspected in a recent thread (https://forum.mflenses.com/tomioka-tominon-c-4-5-cm-f-1-9-t85478.html#1587781) I also believe that the Olympus Pen EED F. Zuiko 32 mm f/1.7 might indeed be the exact same lens as well. It even shares the fate of being repurposed as a stopped-down industrial lens. Very, very suspicious, if you ask me!

Perhaps Ernst Dinkla or someone else on this forum knows more about that!

[Ernst Dinkla]

https://spiral-m42.blogspot.com/2024/07/tomioka-mamiya-tominon-32mm-f17.html?m=1

Good source for interesting lenses.

[Pancolart]