I don't shoot flood light sports so have never foumd a lot of use for very high (Over 800) iso. All the below shoots were at 400 iso using the Panasonic G1 and a monopod.
No matter how good digital cameras get at very high iso speeds they will never be able to fix bad lighting. What would have been the point of shooting these shots at a higher iso speed? Whats the point of trying to record dull flat lighting or light so bad it can never reflect any true colour?
All of these shots were taken in very low light. It was raining outside. If I had been shooting in even worse conditions (Eg On the footplate of one of the engines) I would have used flash not a higher iso. NO, not a built in camera flash but a couple of off camera flashes set up to produce Lighting.I would never state that very high iso performance is useless. For some it could be a very usefull tool but for most of us there is often a better alternative than just turning up the iso and IMO for a majority who want to try and take good images high iso isn't going to be much use.
Photographers really do need to think about lighting rather than all the rubbish talked about the very high (Over 1600) iso performance of digital cameras. More can be learned by experimenting with flash, using reflectors and carrying a camera support (A small bean bag will do) than lusting after a new camera that can shoot noise reduced detail blurring shots at 12,000 iso.
Unless your an indoor sports photographer! If you are I do hope the venue provides lighting that is set up for more than just the average eye.
Don't lust after the latest high iso performing camera. Your time would be better spent learning about lighting.
Perhaps my final thoughts should be :- I love my friend Ian's new Nikon D700 ( http://ianskyphotosite.blogspot.com/ )
Its a great camera. Did he buy it for its high iso performance? To my knowledge he didn't even consider that. To my Knowledge he has only ever seriously used it at 1600 iso for a few hand held night shots. Does he need high iso No. He has never even mentioned its high iso performance to me though he has gone on about so many other features of the camera.
The last time I was doing an indoor shoot with Ian he was using flash ! But Ian is an ex pro he knows how to use lighting.
