Here are some sample from the Contax G35, as compared to the kit SEL2870. What I have done was use a tripod in my living room, and made sure I have the same field of view on the 28-70 as on the G35. I then used zoomed manual focusing to focus on a spot in the top left corner of the image at f4 and f8, and repeated this in the centre of the image , for both lenses. The RAWs were opened in Lightroom 5.3, with no post processing; zero sharpening and noise reduction, exported at maximum JPEG settings, and assembled in Photoshop. The final JPEG was exported at \'very high\' settings at 100% zoom. I figured that process would do for a quick-and-dirty comparison.