Revuenon MC 55mm f1.2 in PK mount

I recently acquired one of these and will be comparing with a S-M-C Tak 55/1.8, K 55/1.8, S-M-C Tak 50/1.4 and an A 50/1.4.
Anyone else with any experience with this lens? - I believe the construction is simimilar to the M42 55/1.2 Tomioka's from the 1970's but made by Cosina in the early 1990's.
Here's a few examples of the Revuenon 55/1.2 shot wide open:
link

I've also got one of these and it's a lovely lens.

There's a bit more information here if you're interested:

link

Is it the one that doesn't have f/1.4 on the aperture ring.
I've got the Porst K version as well as the Tomioka f/1.2 M42
version.

All excellent lenses.

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Pentax K-5 and some other stuff

Algi

My Revuenon version doesn't have an f/1.4 setting.

The aperture ring doesn't get too much use anyway as it's normally set at f/1.2 ...

The Revuenon MC 55/1.2 K doesn't have an f1.4 setting - it goes f1.2 then f2. With a 58mm filter ring and 9 aperture blades I believe it has a different design to the Porst 55/1.2 (55mm filter ring).

Focusing with the Revuenon 55/1.2 wide open appears to be a little tricky due to the very narrow DOF. I've ordered one of the Chinese split prism screens off ebay - hopefully this will make manual focusing easier on my *ist DS, although I've read there may be problems with the screen becoming too dark at low apertures.