The Helios 44 is a must have lens for 2 reasons : the incredible low price and the very good image quality. The focal length of 58mm is quite good for portraiture and the aperture is f/2.0
The Helios 44 can be found on the aftermarket for 20$. It was the kit lens for the zenit film cameras. The optical formula is the same as the Carl Zeiss Jena Biotar. This lens is also called the Russian Biotar.
Mine is the Helios 44-2 which is a preset model. But there are other series like Helios 44-4 ... helios 44-7.
It was the first M42 lens I purchased. I loved the handling and the vintage look. It is built like a tank.
The only issue I had was to understand how to use the preset ring.
I compared the Helios 44-2 image quality with my 2 copy of Minolta 50 AF 1.7 prime:
The Minolta primes were both sharp only stopped down to 2.8 or more. Then they are very sharp but before 2.8 they were quite soft. While my copy of the Helios 44-2 is sharp wide opened.
This lens produce a very nice bokeh and color rendition is excellent.
I found that 58mm focal lenght is more interesting for portraiture on APS-C sensor than 50mm.
Condidering the low price and the excellent image quality, I think the Helios 44 is a must have. This is certainly the first lens to purchase if you plan to use M42 lenses.
Then you will keep it because it is difficult to find a better image quality (even if you spend more money) : I still own my Helios 44-2 while both of my Minolta AF 50 f/1.7 were sold this winter!
on a Sony A300
I tested this lens only on APS-C DSLR (Minolta D5D, Sony A300 and Sony A700)
I have heard about mirror crash risk with some full frame DSLR (e.g. Canon 5D) because the rear lens goes inside the body.
