I'm not sure if I'm completely answering your exact question- but the Canvas sees well beyond "normal" framing. It includes what some refer to as "TV transmitted" which is beyond TV action safe boundaries. We generally do not want to see all the way to the edges of the Canvas on any final projection- optimal framing is to Action Safe (the outside lines in the Title Safe overlay). Also, there is no image information beyond what you see in the Canvas- it shows us all "active picture lines". The black on the edges of the frame is blanking- there is nothing beyong it but more blanking. I can't answer what a projector would see- not my area of expertise.
Hope this helps.
Andrew Balis
Lead Final Cut Pro Instructor
www.moviola.com