On Tue, Jun 30, 2015 at 3:04 PM, John <[email protected]> wrote:
> What advantage does having a backside-illuminated sensor bring to the table? Imaging sensors are made of semiconductors, like computer chips. Part of the semiconductor material is used to capture photons of light and convert the light into electrons. Those electrons are then counted to tell you how bright each pixel is. The circuitry that reads out the pixel values is also part of the semiconductor. In a traditional "front-side illuminated" sensor, the light has to go through the circuitry layer before getting to the part that captures it to turn it into electrons. Some of the light is uselessly absorbed in that circuitry layer. This sounds stupid, but I guess it's the easiest way to build the sensors. In a backside illuminated sensor, things are turned around so the light hits the light-collecting layer without going through the circuitry layer. This can result in a substantial improvement in the amount of light successfully recorded. BSI sensors started out in small sensors, like cell phone cameras, and now we're seeing the first APS-C and FF sized ones. (They've also been used in research-grade instruments for decades.) BTW, the human eye is frontside-illuminated, and the squid eye is backside-illuminated. https://en.wikipedia.org/wiki/Cephalopod_eye -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
