Quote Originally Posted by Sheiky
I see that you use "tweener" iso settings. From what I've heard, iso640 is nothing more than iso800 metering and then adjusted 1/3 of a stop. So quality-wise it wouldn't make sense to use it.

True. Personally, I have C.Fn I-2 set to 1 so only full stop ISOs are available. That also makes it much easier to rapidly adjust my ISO. Note that if you use Auto ISO, the camera will still use the 'tweener' 1/3 stop ISOs even withC.Fn I-2 set to full stops.