Wanting to both streamline and diversify my lenses at once, I discovered this unusual 55/1.8 M42 from Petri.
The yardstick for 55/1.8 lenses in M42 mount has to be the Asahi Takumars. I’ve had half a dozen, and the one that’s endured is a very clean Super-Takumar.
In the past I’ve also had a Fujinon 55/1.8 which was pretty much the Takumar’s equal in the final image, if not quite so well built or smooth to use.
This Petri I researched a little before, but I think there are different versions in different mounts (M42 and Petri’s own proprietary mount) so it was difficult to draw any definitive conclusions.
Nevertheless there was enough promise to keep an eye out for one, and along it came, via my usual source, the wonderful/evil eBay.
Build wise the Petri is classic M42, sturdy, with plenty of metal and glass.
It’s larger than the Tak or Fujinon, but still pretty light.
Of course with any vintage lens, you can only judge it based on the example you have.
Focus-wise the Petri is fairly smooth, if slightly dry.
The throw is quite short, only about a third of a turn from the minimum focus to infinity.
Ah yes, the minimum focus.
Normally anything more than 0.5m I wouldn’t look at and most 50 or 55s seem to go to 0.45m.
Indeed one reason I so like the German lenses like the Zeiss Pancolar 50/1.8 and Pentacon 50/1.8 is their excellent close focus – 0.35 and 0.33m respectively.
So the 0.6m of the Petri isn’t ideal, and noticeably long compared with those mentioned above, but this is alleviated somewhat using it on an APS-C DSLR with 1.5x crop factor, giving an 82.5mm equivalent field of view.
If I want to get closer I can use a close up filter or macro extension ring.
Like most M42 lenses, the Petri has an Auto/Manual switch, which if course with a DSLR with an adapter I leave on manual, as the auto pin is not activated by anything on the camera body.
Something I really like with this lens is there are no click stops on the aperture ring.
Whether this is by original design, or someone has either declicked it purposely, or dismantled the lens and lost the ball bearing that provides the click stop (we’ve all done it, haven’t we?), I don’t know.
Either way, it means that in use the Petri is very similar to my beloved preset aperture lenses like the Helios 44-2 and Jupiter-37A.
That is, the aperture can be infinitely adjusted, depending on the depth of field required.
The six blades form a rounded hexagon as they’re stopped down, which is preferable to me than very straight blades forming a severe attack of the hexagons in the bokeh.
So, let’s summarise the Petri so far.
We have a lens with decent but not amazing build quality, that’s not especially compact, only focuses down to 0.6m and only has six aperture blades.
Doesn’t sound a keeper does it, especially in the company of the Super-Takumar 55/1.8?
However, the Petri isn’t finished yet.
Whilst it doesn’t feel special to use in the way a Tak does, it’s actually very endearing, and the short focus throw and clickless aperture really appeal.
Even better, the magic of this lens is in the bokeh.
Even wide open.
Especially wide open.
Many lenses claim a fast aperture but then aren’t really usable until they’re stopped down two stops.
The Petri CC Auto delivers something I’ve not seen in quite the same way from any other lens I can recall.
Yes the Takumar and Fujinon give perfectly pleasing bokeh, and the Helios can be teased into delivering dreamy swirls like nothing else I’ve used.
But the Petri manages to do something different.
The best way I can describe it is renders backgrounds like a beautiful watercolour painting left out in the rain.
At the same time being at least as sharp as I would ever need a lens to be.
Needless to say, the Petri has solidly secured its place in my kit for the foreseeable future, and I’m greatly looking forward to using it again.
All photographs in the post made with the Petri CC Auto 55/1.8 on my Samsung GX-1S 6MP Pentax K mount DSLR. Click on any image to see full size on Flickr.
Which are your favourite lenses for bokeh?
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35hunter 
The rendering and bokeh remind me of Rikenon lenses. The term “rained on watercolor paintings” goes right on with those.
I like the images it produces, very clear with that pleasing bokeh.
My lenses for bokeh are of course first of all the SMC 50mm f/1.2 – I don’t have anything quite like it. The Pentax DA 35mm f/2.8 Limited has great bokeh when doing closeups. And the SMC-M 100mm f/2.8 is also great at bokeh and isolating subjects.
One lens I think I need to re-buy is the Rikenon 50mm f/1.7 (XR or P). It was very pleasing wide open and super sharp closed down, but it really nailed that kind of bokeh you are describing.
I’ve had quite a few of the K mount Rikenon 50/2s and they punch well above their weight. Some I’ve paid like £4 or £5 pounds for and they’re excellent, from wide open, small and light. There’s a smaller and a larger version, well, same diameter, just one is quite a bit shorter in the barrel length, and almost pancake like.
Just the minimum focus of 0.6m is a bit disappointing compared with the more usual 0.45m, or sub 0.35m of a Petnacon 50/1.8 or Zenitar-M2s 50/2. I think I’ll dig out some of my Rikenon pics on Flickr. I featured it here before too – https://35hunter.blog/2017/04/27/lens-love-3-ricoh-rikenon-50mm-f2-pk/ – and it does have pretty appealing bokeh.
I had a 50/1.7 briefly and hoped it would be as good if not better but don’t recall it wowing me much. Decent enough, but there are half a dozen 50/55s I’d choose before it, including the compact version 50/2! Maybe I’ll seek out another for another 50mm shoot out…
I think the 50mm f2 is at the same time the sharpest and the worst Rikenon 50mm lens. How can that be? Sharpness isn’t everything… yes it’s still a good lens, but the pictures don’t have a “wow” factor to them. The bokeh is uninteresting. The MFD, as you mentioned, is pretty bad as well. And the focus throw of the focus ring is really short, making it very hard to focus in medium and long distances. That is the one Rikenon I won’t buy back.
There’s a couple completely different Rikenon 50 1.4 lenses… yes I have both 🙂 The older XR is only sharp wide open depending on how the light falls on the subject. Aberrations are terribly controlled, so any bright light will cause softness and an effect a bit like the “soft lenses glow”. Close it to f2 and it’s not super sharp but it’s very pleasing. At f2.8 still not super sharp but it’s got an interesting 3D effect. And from f4 and smaller it’s sharp. The MFD is closer than my other 50mm lenses (excluding the Macro). Too bad the aperture broke and it’s probably not worth fixing…
The other one is the Rkenon P 50mm f1.4. That lens is a completely different design – the bokeh isn’t quite as good as the XR version but still pretty decent. It’s quite sharp from wide open and super sharp from f2 and down. I consider it my best 50mm lens. It’s quite rare though, and can get pricey when you do find one. People have realized how good they are… way better than the Pentax 50 1.4 lenses in many ways.
You know very much about many lenses! Never had a Rikenon 50/1.4, but I did pick up an Auto Chinon 50/1.4 the other week. I’ve had a couple of the 50/1.9s (very average) and more still of the 50/1.7s which are very good, very close to the Pentax-M 50/1.7. So I have high hopes for the 50/1.4. Hasn’t set my world alight yet, but to be fair I’ve hardly used it yet…