its the same. its just that zeiss lens has warmer rendering compared to yashica. in short, the quality is the same, but the characteristics maybe differ. just a minor difference in the coating, thats all. i got the yashica 50mm f1.4.
may i know what shutter speed u use? i tried to do this kind of stuff but always failed to get the correct exposure. two rolls already wasted. feel like giving up and go back to digital. :D
why people choose GRD2 instead of GX200 ?? they are both the same, but GX200 got optical zoom. i know prime lens usually are better, but on small sensors it wont make much difference.