Digital Camera Interface w/iBook in Real Time-not for download

I need my iBook to see what my digital camera sees in real time - not to transfer photo files, etc - just for my iBook screen to see what my camera is seeing while it is turned on. Will EasyCap video capture do this (just attaching the EasyCap to the USB port and connecting the camera to the RCA vid port and leaving the rest of the connectors empty since I don't need audio and I'm not doing video)? I know someone who did this with a PC & a analog to digital TV converter - is this the only way to make this work for a Mac? The reason I need this to work in this unique way is that I will be mounting a digital camera at a set point above some documents to take high-quality photos for digitization and I won't be able to see the camera screen since it will be mounted 2 feet above my head and away from my vision. Any help is appreciated. Thanks.