Aha, I see... Well don't know about Aperture, but I tried DSLR Remote on my PC and 30D and it works flawless. Don't think there is a Mac version of DSLR Remote though.Teathering is when the camera is hooked up to the computer. When you shoot it displays the file on the screen for immediate inspection and tranfers it into a folder also. It saves the file on a card and the computer for greater security.