Now some cameras even go much higher in ISO especially your' higher priced ones but I have never used one that shot at an ISO higher than 3200 so I'll save those post for a day when I finally get my hands on one, however one thing is for certain from the studying I have done on some, and that is the technology just keeps getting better in the ISO area and they are looking less and less grainy when shooting at a high ISO as time goes on which is great to know for someone who uses natural ambient light to photograph wildlife instead of trying too use a flash which would scare the life out of most wildlife or for dangerous wildlife well,,,, lets just say for example you are a bear and some human walked up and popped a bright flash in your' eyes, "what would you do if you were the bear? :)
Now since you have had a few seconds to ponder that idea for a few seconds lets get back to the subject of ISO, I have a couple of more photos too show you for an example of a high ISO these photos were taken in low light conditions, "how low?",,, very low, in fact they were taken at around 8:00 A:M in the morning before even the sun had it's first cup of coffee :) yes that early, O.K., now that I told my little sun and coffee joke I will get back to being serious, though both of these photos were shot in nearly the same kind of conditions at around the same time of the morning, however you will notice that photo A looks less grainy than photo B however I did use a slower shutter speed in photo A than I did in photo B however the bird in photo B was moving much faster, well in fact he was flying and if I would have used the same slow shutter speed that I used in photo A then photo B would have been nothing but a blur.
Photography And Nature