I thought that focal reducer can bring some image worsening (blur, reflections and whasoever) so i was prepared for. But I can't notice any worsening. This one is good enough for M42 lens. Manual focus error may be far bigger, I can't notice any picture degradation, see crops from sample photos wit & without the reducer. Of course in corner image can be perceived as 'worse' but seems it is because the M42 lens image is worse there... and without reducer you just haven't seen it. The only problem may be a flare when you go to f/8 - f/22 - but who buys reducer to close M42 lens so much? We want to use them wide open and then no such flare at all....
sample with and without the reducer
I thought that focal reducer can bring some image worsening (blur, reflections and whasoever) so i was prepared for. But I can't notice any worsening. This one is good enough for M42 lens. Manual focus error may be far bigger, I can't notice any picture degradation, see crops from sample photos wit & without the reducer. Of course in corner image can be perceived as 'worse' but seems it is because the M42 lens image is worse there... and without reducer you just haven't seen it. The only problem may be a flare when you go to f/8 - f/22 - but who buys reducer to close M42 lens so much? We want to use them wide open and then no such flare at all....
sample with and without the reducer