I am still new to my Olympus E-PL1 - so bare with me... The default of Olympus E-PL1 Auto Iso starts with 200 Iso - the manual starts with 100 Iso. I can recall that some say the 200 Iso has a better Dynamic Range. I have tried to compare the two option outdoors in a clear bright sunny day, and it seems as the 200 Iso images are more grainy and "dirty" look over all the image, mainly in darker areas of the image, while the 100 Iso images and cleaner. Other than this I did not notice any differences. Any idea why and comments?