Since modern multicoated lenses transmit more than 99 percent of the light that hits them (<1% reflection) I doubt that's ever visible. A poorly designed mirror box or relflective metals on the lens rear surfaces would be more like culprits than the lens optics in causing unwanted stray light reflections I would think. jco
-----Original Message----- From: David Oswald [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 06, 2005 1:23 PM To: pentax-discuss@pdml.net Subject: Sensor reflection Godfrey alluded in another post to the fact that there is a possibility of sensor reflection affecting an image. This hadn't previously occurred to me, but makes perfect sense. So that begs the question; is it possible that some of what we often think we see as CA is actually a reflection off of the CCD back to the rear element, and from the rear element back to the CCD? The CCD is a pretty reflective surface. I suppose that's a necessary evil. This is asking a question of speculation... Is there any point for camera manufacturers to investigate the possibility of non-reflective CCD's? Or is that simply an impossibility?