Thanks Caveman. Your links helped me learn a lot, much better than the hearsay and rumors from the Internet !
I was reading the document about the 11 megapixel sensor from Kodak. (The second link) "The use of a microlens above the photodiode significantly increases the QE of the sensor, but it also produces some undesirable effects. The most troubling of these effects is angle roll off - the decrease in response with the angle of incidence of the incoming light. In the case of normally incident light, the microlens focuses incoming light into the photodiode aperture. However, light entering the microlens at higher angles can be directed away from the photodiode and lost." You can see from Figure 4 the horizontal and vertical angle response for a pixel. It seems rather clear from the graph that in the horizontal direction there is sharp drop-off beyond +/- 10 degrees and in the vertical direction it is good to about +/- 20 degrees. Even with a mirror box there is no guarantee incident light will come in within these limits. I am guilty of believing in urban legend as Mark accused, but it seems this time urban legend and manufacturer's technical paper match well on this issue !!! -- Bo-Ming Tong
