I've been using the S400/S500 for over a year and was annoyed by the relatively slow shutter speed. So, I changed my ISO from 50 to 200 for this trip. I think it did help the shutter speed but it hurt the noise level. My pictures of the Manta show quite a bit of noise. I'm going back to ISO 50 for any future trips.
Image by Cabo (Copyright) posted at ScubaGallery
Image by Cabo (Copyright) posted at ScubaGallery
Image by Cabo (Copyright) posted at ScubaGallery
Posted pics:
http://www.scubaboard.com/gallery/showgallery.php/ppuser/12117/cat/500



Posted pics:
http://www.scubaboard.com/gallery/showgallery.php/ppuser/12117/cat/500