[bmauter]

Originally Posted by inkista

No. What I'm saying is that really fast lenses tend to exhibit this more frequently than slower lenses, and stopping down (using a smaller aperture) will minimize it. Also avoiding overexposure/blowing out any highlights/backlit subjects/hard specular highlights--but sometimes you can't control that. Purple fringing and sensor bloom are a different kind of chromatic aberration than is usually talked about (the cyan/red variety, where the refraction of the glass has caused light of different frequencies to separate to different locations). Purple fringe and red fringe are typically caused by some form of sensor bloom, where the charge on the sensor overflows to neighboring pixels. I think. It's been a while since I looked up the varieties of CA.

Sorry, didn't mean to imply that you said to nail focus. One of the links that LoveDSLR included was from Ken Rockwell. In there, he directly states that "There aren't any color fringes, so long as you're in perfect focus." I think I got lost in all of the reading and replying.