The Auto Revuenon 55/1.4 Lens
Just recently I bought an Auto Revuenon 55mm (f/1.4) lens off of ebay. It came with an M42 screw mount, fitting an adapter that I’d already had. For less than €40, it didn’t take a lot of time to decide; and the fact that I confused it with the multi-coated 50mm f/1.4 lens, which actually appears to be quite a bit better, probably also helped. I had hoped that in comparison to my Zenit Helios 44-2, the larger aperture (1.4 vs 2.0, implying twice as much light!) would allow for photos taken in even darker conditions. And, of course, more bokeh. Because that’s what we all want, after all.
Was it worth what I paid for it? I’d say yes. Would it be worth much more? Hm, maybe a bit, but probably not more than roughly €100.
However, given that even the title photo of this website was taken with this lens – I’d really be careful to call it “bad”. Rather, “challenging”, maybe? Starting from the good parts, it really doesn’t have many problems when operated at f/4 or smaller. As usual for prime lenses, the image will be sharp, with a lot of contrast, even in bright conditions. There is nothing bad to say about the image quality at small apertures. However, we don’t buy such a lens to use it at f/4.
Wide open: f/1.4
At the other end, very wide open at f/1.4, we see the lack of a proper coating make the difference. Some light from a wrong direction (the side, notably) immediately destroys contrast, and any contrast that was left on bright/dark borders is overcast with a light fog. This can make for a nice retro look, but sometimes just isn’t desirable.
But: that doesn’t make it completely useless. In fact, many sample images you can find for this lens elsewhere share a “somber” look, like in this photo of a dandelion taken a bit before dusk – with low contrast, the lens really does a good job (even though the bokeh balls have a circumference that is a bit too bright):

When we just need all the light we can get, it still doesn’t show much weakness. Although this was taken at f/2 or something in that range:
With bright lights, we then see diffraction artifacts as strong as I haven’t seen in other lenses yet – even at large apertures! This isn’t too bad, in fact it creates an interesting look. Another characteristic are the rainbow caustics; if you hold it right, you will even get a reproducible rainbow halo, which can be a nice gimmick for portraits.
And the nighttime bokeh is alright, if the lights are bright enough. Light sources that are faint will show as “donuts”, with bright circumference and weaker area.
Sharpness is not a problem at all, even at large apertures, if the foreground doesn’t contain a whole lot of contrast, like here:
For all its problems, which stem from the fact that this Japan-built lens was a no-name product for photo amateurs in the 1970s/80s, for all I know, it’s still very fun. It’s not perfect if you need every photo to be perfect; but in turn you get spectacular results once in a while. And at about 5% of the cost of an “every-shot-works” lens (Sony G etc.), there’s really nothing wrong with that.
The photos shown above are completely unedited, straight from my camera, only slightly compressed using ImageMagick.
Update (2021-06-22)
A couple more photos with this lens, with daylight and smaller aperture. At f/3.5 and smaller, I have been quite amazed at the sharpness; it often surpasses the sensor’s resolution limits at 24 MP (APS-C)!
Poppies, at sunset, using internal reflection for a retro-ish vibe:
Bokeh is very nice when the aperture is smaller, and still very soft due to the
relatively long focal length: