So, I recently picked up the Sigma 30mm f/2.8 DN Art lens on the recent Amazon Gold Box daily deal. Thought it was an unbeatable deal and wanted the 30mm focal length at a nice fast-ish aperture. However, after a couple of shots around the house, especially some outdoor ones of the house in good light, I noticed something odd... what appeared to be some color bleeding, but I quickly realized was noticeable (to me) chromatic aberration. I've noticed CA in shots from my other lenses, including the SEL50F18, but thought what I was seeing from the Sigma was... excessive. So today I did a couple of quick test shots of the branches of one of our trees against the sky. I shot the Sigma at f/5.6 on a tripod, and then shot the same spot with the SEL1855 set to 30mm and f/5.6 also. Looking at max magnification in iPhoto (which, as I later learned, is way more than 100% magnification) the Sigma shot had noticeably more CA, especially at the outer portions of the frame. So here is a 100% crop of the top right corner of the test shot of the tree using the Sigma 30, on a tripod to ensure as close to the same conditions between shots as possible. This is a straight export of the RAW image, no in-camera processing. CA Test - Sigma 30 by SRHawk64, on Flickr And next, the SEL1855.... Oddly, the SEL1855 had a faster shutter speed... maybe that was because I had left OSS on. Again, a straight export of the RAW image, no in-camera processing. To my eyes it appears the SEL1855 has noticeably less CA. CA Test - SEL1855 by SRHawk64, on Flickr What do you guys think? Am I imagining it or does the Sigma have more CA in these shots? And is this normal for the Sigma? Am I paranoid/overly-critical? Or should I send this copy back?