Canon’s 1Ds Mark III offers a means to customize the factory specified four-digit camera name that precedes the four digit file name. In the process of implementing this option, I encountered a problem which had no answer in the documentation—at least not that I could find. Under the Tools 1 menu, I set the custom four digits to my preference (In my case, four numbers). However, after taking pictures and downloading them, the custom four digit included an unwanted underscore character “_”. I later found out from Canon that the underscore is a default naming convention for the Adobe RGB color space, the custom file renaming option only works if the color space is set to sRGB. If you shoot in RAW, the color workspace does not really matter since you can change that if and when your processed files are output to another file type. The color space is set through the Camera 1 menu.