Went to the Botanic Gardens last night to view a chinese lantern/light display type thing.No flash or tripods allowed so not a lot to be captured.I decided to use the opportunity and set the camera [Canon 20D] to ISO 1600 to see what happened.Have not got a lot to show but here is one which I am pleasantly surprised with.Yes,it's very noisy and appears unsharp but not too bad for a handheld shot with no handy fence /wall etc to brace myself against. The settings were 1/8th sec @ F4 and ISO 1600.
Now,with a newer camera that handled noise better,set to ISO3200/6400 and using an Image Stabilised lens what would be possible.....