I'd second Voe's comments (except ranking it above the Helios :-) and might add that this lens seems quite good really in the near distance range (i.e. flowers etc) and the blue color spectrum. Remember that 30cm is 30cm from the sensor, not the front lens. I only have MC (=multicoating) versions of this lens (quite a lot actually) and they seem to not have a lot of build spread. The price is like sub-10$ sure, but the build quality is much higher.
The softness can be taken care of quite well in Postprocess imo, cause it is just a lack of contrast in the lower aperture range, resolution is still there and you can pull it out if you want to.
Quote: zntgrg said:
1) It's awful to stopdown, you have to push a little switch on the barrel...with a DSLR it is barely unusable.
I'd recommend doing the cotton swab shaft job on such lenses or just look for a lens with an A/M (auto-manual) slider switch.
Typical M42 lenses: Above pic shows the Auto pin (metal pin coming out of the back near the glass in the 8 o'clock position). A-M swich is a slider on the outside of the barrel in the 6 to 8 o'clock position. If that slider switch is not there but only a temporary stop-down switch or nothing at all, then it is best practice to mechanically lock the above-mentioned pin. Pushing it will stop down the lens if you want to test it - there is your 'Auto' function. The locking is easiest done by removing the back plate (4 outer screws here) and put a little peace of cotton swab shaft onto the pin from inside, then close the lens again. There is your 'manual' lens. When pulling the back off beware to leave the aperture ring where it is cause there could be a tiny ball jumping out (there was your click click click .-(
Quote: zntgrg said:
2) Really, really, prone to lens flares.
Never had this on my MC copies. I'm using a lens shade all the time though. All MC versions have the above-described A-M slider switch also.
The above-pictured M42 lensbacks are typical for most of them, which includes almost all M42 Takumar lenses as well as the huge majority of any M42 lenses available (which still must be millions).
Hope you have some fun with those full-metal handcrafted goodies,
Georg