Sensor sizes

[jonhd]

Apologies for the techie nature of the content. May be of interest to some of you, and is intended to illustrate (to scale) the relative areas of the sensors used in most of the popular types of digital camera.
It says absolutely nothing about chip noise performance, chip type (MOS, CCD, etc.), pixel density, etc. - i.e. all of the other things that contribute to PQ. It's purely to illustrate how much light hits the sensor!

Digital camera sensor sizes

Toodle-pip, Jon

[MikeOxon]

Reminds me of the old adage from film days that "a good big 'un will always beat a good little 'un"

In the digital world, however, there are other factors to take into account; for example, some of the newer technologies were introduced first on smaller sensors (for cost reasons). As a result, some small sensors performed beyond what might be expected, simply on size comparison. I'm thinking of back-etched sensors, for example. In a conventional digital sensor, the 'wiring' on the front obscures a significant fraction of the sensitive area. By etching away the back and turning the chip over, more of the sensitive area can be exposed to light. As far as I know, this is still only applied to smaller chips, for both technical and cost reasons.

There are so many practical advantages to smaller sensors (and, hence, lighter cameras) that much of the research is concentrated on these, so that, for most users, a smaller sensor can now provide more than adequate performance, at least in good lighting conditions.

Mike

[jonhd]

Agreed with all of that, Mike. It's also fair to say, I think, that (generally) what's developed for the smaller sensors, makes it into the larger sensor designs, too. Although, of course, with nothing like the rapidity of deployment in the smaller (mass market) sensor arena.
For the likes of Nikon, Canon, Pentax, Olympus, they're becoming increasingly dependent upon the 'big boys' (Sony, Panasonic/Matsushita, Samsung, and so forth), for sensors. I believe that Sony are finding it increasingly difficult to compete at that level?
One area where they can (or could) all compete more fairly, is the image processing 'engine', of course. But that's no longer a generic CPU + Firmware kind of architecture, and is now increasingly hardware (ASIC) based - which is very expensive to develop. Which is also why poor releases can't necessarily be fixed by software upgrades.

BR, Jon

[Jack Harrison]

See this about the all-important (and limiting) effect of diffraction.

http://www.cambridgeincolour.com/tutori ... graphy.htm

Unless you can somehow beat the laws of physics, small sensors can NEVER equal the quality possibly with big ones.

But for practical purposes.........

Jack

[NickC]

For the likes of Nikon, Canon, Pentax, Olympus, they're becoming increasingly dependent upon the 'big boys' (Sony, Panasonic/Matsushita, Samsung, and so forth), for sensors. I believe that Sony are finding it increasingly difficult to compete at that level?

Canon are unusual in that they don't rely on other companies for their sensors, they make them all themselves, and have done for all except the very earliest of their DSLRs.