That's exactly right. And it's a pain in the butt! I take 10 minute astroexposures and I have to wait another 10 minutes for it to return to the ready state. (You have to use an external control and set the exposure to "bulb"). I can't see in manual mode where to turn off the noise reduction though (haven't looked but sure don't remember it- so, pending my looking for it specifically). But, at the end of the day, it's all software and unvalidated marketing crap. That's my T3i. I have a T3. It doesn't do that. And the images- even at 10 minutes- are equally good. Bottom line, they've wasted untold hours of peoples' time with a very questionable feesure. The tilt screen on the T3i is really necessary for astrophotography unless you're a contortionist. But I'm going on a two day astrophotography trip and I'm taking my T3 for objects that are at a low angle just so that I don't have to wait for the noise reduction on an object where I really don't need the tilt screen.
