Digital camera settings?

OK. So say i'm shooting on shutter priority. Everything looks great. Then the sun goes down. Which should i change? Turn down the iso or the exposure?

I might be wrong but low light conditions need a higher ISO and slower shutter speed.
But the down side of higher ISO is Your capture will get grainy.

http://www.wakeboarder.com/display.phtml?id=553

Thanks Walt. I've read that and i just read it again. But i really didn't see anything to tell me the difference between moving the iso and moving the exposure. Maybe i missed it.

Like for the pics i was taking this weekend at The Nationals. I would commonly have the iso @ 50 and the shutter speed at 1/800. Then the sun would go away and i would turn the iso to 100 or raise the exposure to + 1/3 or both. I'm just wanting to know which one i should raise, and what effect it would have on the picture either way.

Jeremy, post Your ? on this forum and I'm sure You will get the answer. http://forums.dpreview.com/forums/forum.asp?forum=1010
I'm still working on low light situations too.

I generally shoot ISO 100, 1/2000 @ f4 for bright sunlight. As the sun goes down I will drop the shutter speed slightly but not less than 1/1000. At that point I will increase the ISO to compensate for the loss of light.

Increasing the ISO will allow you to continue to shoot with the same settings with less light. Decreasing the shutter speed will result in more motion blur due to the high speed movement that is inherent in wakeboarding. How high you can increase the ISO and still get good results is dependent on the camera. Most are able to go to ISO 400 without grain/noise becoming too much of an issue. I've shot ISO 3200 with my new camera (Canon 1D Mark II) and the results were acceptable after running the image thru a noise reduction program such as Neat Image. Here is an example of a shot taken right after sunset at ISO 3200 1/1000 @ f4 after using Neat Image and resizing for the web with minor sharpening applied.



and here is a 100% crop before noise reduction (no changes to the image except to save it at 50% quality jpeg).

that camera is amazing from what ive seen. It really all depends on what camera you are shooting with. If you are using a DSLR most are able to get to 400 iso with the occasional ISO800 images that are acceptable. IF you have a regular digital camera depending you may only be able to get to 300 or less.

heres one f4 iso 800 1/1000 after sunset and after usm and neat image shot with digi reb and f4L 70-200