Sensor sizesTaken from Wikipedia

There are many different reactions you get from people when they see you carrying a DSLR with a reasonable lens. Having a two year old child, I’ve attended a number of children’s birthday parties recently and inevitably have ended up standing next to another father watching our kids, cameras in hands.

They’ll normally say something like “That looks an impressive camera!” and I’ll reply wittily “Yes, digital cameras are so compact these days.” And then they’ll show me their digital compact in an almost embarrassed fashion. There’s nothing to be embarrased about of course – you can get some great shots from a compact. But it was only after another parent told me how superior his Canon G9 was to my D200 that I felt the need to take him down a peg or two.

Now at this point you can rightly say that a great photographer with a G9 will produce better images than an amateur with a D200. But for arguments’ sake let’s say their equal, or at least look at it from a sensor point of view. A G9 has a sensor 7.6 x 5.7 mm in size, bigger than many compact cameras, but no bigger than a fingernail. The APS-C sensor in a D200 is nine times bigger – and the full frame sensor in my D700 is twenty times the size!

Is it any surprise that compacts suffer at high ISO, or even just going above ISO 400? It’s not. The surprise is really that you get such good images at all. It’s a marvel of technology really.

So much so that I’ve actually purchased a G9 for my Wife. Why? She won’t carry a DSLR – which rules out a D40 or D60 which would have been ideal. And the biggest problem we have with a compact and an active child is that to get “the moment” you need a minimum of shutter lag, which the G9 seems to be the best – right up until the G10 was released!