I got myself an old sovjet lens! A MIR 20M. 20 mm and f/3.5. I have been testing it a bit. Seems like an ok lens with some goods and bads. The good thing is the sharpness really. As you can see below on the test I did. Its another league than the kit lens (DA 18-55). The corner sharpness is at max at F16. Maybe its not fair to test a prime against a cheap zoom, but I have no other in the similar range. And I guess the kitlens is something everyone can relate to anyway.
Corner sharpness. 100% crop. Tripod used.
The centre sharpness is pretty good at every aperture.
Barrel distortion is as bad as the kitlens, but its CA is alot better. There are two really bad things with the MIR I think. The first is flare. It really ruins a photo if the sun hits the front lens. I can live with some flare in my photo but this becomes too overwhelming. Also there is no hood for this lens, so you simply have to deal with the flare yourself. The second bad thing about it is the bokeh which can be plain ugly at times. See the photo attatched below. Light falloff is good. Very hard to notice in my photos.
Surprisingly it is as wide as the kit lens at 18mm. Maybe pentax measures this with including the effects of the barrel distortions and the MIR does not. I dont know.
I dont think I will use this lens much. Its simply too big. Especially concidering you can get the tiny DA21 with pretty much the same specs. I wish I could compare it directly to that, but I dont own it. But the Mir is the most awesome souvernier from my holiday in Russia.
Beats any matroska at least.
The MIR 20M
Bokeh. 100% crop.
I dont remember the aperture at this one. Its not stored in the EXIF using the MIR.