Review of Auto Yashinon-DX 50mm/1.7 m42-lens

Old Yashinon-lenses are not often mentioned in discussions about which M42 SLR-lenses to get. Well, not as often as Takumars and Carl Zeiss anyway. I think this might be bacause they are underrated, or maybe just not as common. Many might associate them with the Contax/Yashica-mount of later Yashica lenses. But there are some great stuff for your M42 camera or adapter if you'll take a look...

The purchase
I bought a Yashica J-7 here in Sweden with this lens on it. Both the camera and lens are in great shape, no marks and great glass. It has yellowed a bit but I haven't noticed any impact on my images.

Yashinon-DX 50mm f1.7 m42

The lens
It's quit an odd construction, with inner tube alu-metal and focusrings in black plastic. The aperturering is very thin, but has big notches so you can easily turn it any way. It has a manual/auto-switch, that works on old Yashica M42-cameras. The switch is under the lens and hard to use while looking through the lens - so it's not usable as a shortcut to stopping down the aperture as you can do on some other lenses with such a switch.

Yashinon-DX 50mm f1.7 m42

This normal lens it's avarage sized, maybe large, for a 50mm. It takes 52mm filters, which is good because it's the same filtersize as my Yashica MLs, Helios and Canon EF.

Yashinon-DX 50mm f1.7 m42

The lens has thorium in it, the radioactive substance that makes many old lenses turn yellow *. If you get a yellowed one you can put it in the sun for a few weeks and the tint will go away. The radioactivity is not much to worry about, remember this are lenses constructed to be close to negative film in analogue cameras.

Yashinon-DX 50mm f1.7 m42

I should use this lens more then I do, because every time I get some great shots! Good soft bokeh, sharp where I want it to be, saturated colours. I feel it suitable for nordic blue dark november for some reason.

Mounted on Canon EOS 350D:
Bumblebee 1 Bumblebee 2 Blue spider Branch with leafs Dark forest

Mounted on Yashica J-7 with Tri-X 400:
Bumblebee 1 Bumblebee 1


  • Lovely bokeh and colours
  • Sharp
  • Big notches on aperturering, so you get a grip eventhough it's thin and close to camera
  • Fast
  • Good buildquality
  • On some Yashica SLRs the auto-function works


  • The yellowing by thorium
  • Single coating (although I don't really think that's a big con)
  • No easy "aperture-open-button"
  • Actually, I can't think of that many cons - it's a great lens.

* Update
According to some insightful readers I have learned that the thorium doesn't have more then background radiation and should not account for the yellowing. Maybe that is simply the coating of the lens.