Tiny Tuesday: "Complicated"

For digital photographers, I reckon there's nothing more complicated than the sensors in our cameras - even if it's a smartphone camera. It looks very pretty when one looks in, often producing nice rainbow colours. And it looks simple - rather like a mirror. But it's not!

Over the years sensor technology has developed a lot (and is still developing). The pretty rectangle is the sensor on my OM1. As on many recent cameras, it's "backside illuminated" - quite an odd term, don't you think, Lol?! Older sensors had the electronics and wiring on the front, meaning that light had to pass through this layer to reach the sensitive pixel elements on the back resulting in some loss of light. Apparently that made it easier to make them - and mimics the human eye where the nerve fibres of the retina are in front of the photoreceptors. A backside illuminated sensor is flipped so that the light sensitive elements are on the front (ie what used to be the "backside") - resulting in various advantages including slightly better sensitivity in poor light. Interestingly squids and related animals have a backside illuminated retina - so they're more advanced than us!

This sensor is also "stacked" - meaning another layer of electronics is stacked behind the first layer, resulting in faster readout and processing of data.

When you think that 20 million photoreceptors are packed into such a small space, and all have to be "read" quickly (the OM1 can record 120 RAW photos per second), it adds to one's appreciation of the complexity! (In fact this sensor has 80 million photoreceptors which aids rapid, accurate focussing although it only outputs at 20 megapixels - but that's another story only for technophiles.)

I've included the gold electrical contacts on the photo - as an indication of how complicated the communication between camera and lens is.)

Many thanks to our TT host Loisbiz for giving me the opportunity to be nerdy today ;-))

(Note: This photo was taken with my old EM1 camera, which doesn't have backside illumination. Cameras can't (yet!) take photos of their own insides - Oh well.)