If you are not sure whether to buy the original Biotar or the copy Helios-44, this post will give you some help.
It is well-known that after the end of World War II, the Russian gained access and control of the German optic factories, took some of their glasses and designs back home and produced their own copies of lenses. Helios-44 is the Russian copy product of the German Zeiss Biotar.
I have both the Biotar and Helios-44 with me. I think it would be fun to make some photos and see how big the difference between them really is.
However, according to the serial numbers and google-search, the two copies were made in different eras, the Biotar should be made between 1955-58; the Helios in 1968. They should have the identical optic design, but I suppose 10 years might make a big difference in terms of lens coating technology.
It is not a scientific test. I just made some photos with the two lenses and then compare them side by side:
Photos on the left (or upper photo when view with phones) were taken with Carl Zeiss Jena Biotar 58mm f2, 10 blades, in M42 mount; on the right (lower) with Helios-44(-2?) 58mm f2, 8 blades, in Zenit M39 mount.
The sharpness and Bokeh characters between the my two lenses are very very similar, I would say identical. If you are after the signature wide-open sharpness with swirly Bokeh, both can delivery you the same result. But they do have different number of blades. Be aware if this matters to you (see reference links below).
But my Helios-44 copy has better contrast and has a slightly colder color. I suppose these have to do with lens coating. On the other hand, they are very easy to adjust and manipulate in the computer....
My Helios-44 can focus slightly closer than the Biotar, but it is not a big difference. I am not sure if it has to do with the adaptation from M39 to M42 mount. Also, be aware that different versions of the same lens have also different minimum focus distances (see reference links below).
The Helios-44 can be found much cheaper than the Biotar (which also means Biotar has more value). But there are so many versions of Helios-44, and the build quality variance between the copies is so huge that whether you end up buying a very good copy or a very bad copy depends completely on luck. I am lucky to have found a copy that is in very good shape, but I think one should always bet on "made in Germany" when it comes to build-quality.
So..... which lens to buy? You be the judge.
Share with me if you have more comparisons between these two fantastic lenses or versions!
Different versions of Biotar: here
Different versions of Helios-44: here