In comparing several new models of digicams, I cannot relate the size of the CCDs to the no. of pixels of resolution. For example, the Fuji MX-2700 has a 1/1.7-inch CCD (biggest by far!) giving 2.3 million pixels but the Nikon CoolPix 950 has only a 1/2-inch CCD and yet can still offer 2.1 million pixels! Actually, how important is the CCD size to in relation to quality of resolution? And how does the equation work?

-- William Chao (willchao@netvigator.com), June 19, 1999

Answers

One dain-bramaged tinkerer's opine:

My GUESS is that any size difference might be due to the use of different light sensitive materials or a different manufacturing process in the two sensors. Perhaps the sensor Fuji uses in the 2700 is a totally new design. Their past best efforts used 1/2" 1.5MP CCD's AFAIK. There doesn't seem to be much technical info on their site regarding the MX2700, yet. They do mention a 1/1.8" 2.3MP sensor...

I doubt the sensor size matters too much as long as the lens system is matched to it and the sensor gets enough light. Seriously, the only possible difference I can see is that with a physically larger sensor you may(?) be able to collect more charge per cell in a shorter period of time and get a brighter image with less light... However, reading the comments on the MX2700 doesn't seem to bear this out when compared to a Nikon 950: "Well yes, the CP950 will in fact do much better in low light..."

I can also see where larger sensors might more easily allow for digicams that use conventional 35mm sized lens, other than that I doubt it makes much difference. Then again, if I recall my Physics, those larger diameter lens do allow for more light gathering...

Anybody know the nuts & bolts for sure? Dust off that optics expertise and share, I'm feeling too lazy to go look it up. :-)

-- Gerald M. Payne (gmp@francorp.francomm.com), June 20, 1999.