I am relatively new to photography. I upgraded from a Panasonic P&S to a Rebel Xti this summer. I have been reading about the color spaces and pixel sizes and I have a few unanswered questions: 1)Assuming that larger pixels equals less noise does this mean if I take the same pic wit the same settings at 10mp and 8mp on my Xti I will have less noise on the 8mp? Is this equivalent to reducing the quality later? Is this a stupid question, am I missing something? 2)The color gamut for Adobe RGB is larger than that of sRGB but they have the same 8bit per channel plus on alpha channel. Thus ~16M colors limitation is the same for both spaces? Right? Are there ways of capturing more colors and/or light variations without this bracketing HDR business. It this a color space or camera or both limitation. Are their alternatives or ways of capturing say 12bit or 16 bit per channel. I don't mean going to 16bit per channel when editing I mean capturing it. I realize that a conventional monitor is limited to 16M colors so I am not sure how you could view it all without some loss. 3)I was wondering about the optical limitation of the human eyes. How many colors can we see? How many alpha channels? Maybe this quesiton is beyond the scope of this forum but if you have any idea I would love to know.