I have a different Canon scanner. I have Photoshop CS5. If I launch it in 64 bit version, only WIA mode is available. Therefore I launch the 32 bit version, which has the TWAIN plug in, and then I have the flexible list of options you mention. Which Photoshop do you have, and is it in both 32 and 64 bit versions? There are ways of adjusting in WIA. I will have a look and post back later.