Hi Raphael. Excellent question. A bit beyond the range of our little discussion group, but still apropos.
Tony Gay recently posted a link to a -- imho -- very helpful group of lessons.
The first one really helps clarify just what a "pixel" is. The second one begins to explain the relationship between pixels and bytes. Did you happen to see it -- and if so, have you clicked through and read the lesson on pixels? I ask because understanding what a pixel is, and what the relationship is between pixels and bytes, is central to any discussion of the size of digital images.
(Sent from my magic glass.)
Thank you Kirby. No, I haven't but thank you for directing me to it; I will definitely read it.
There is a whole range of decisions a photographer has to make that are dependent on a few key technical answers. One wrong turn and the investment in time and equipment is wasted.
So this is VERY helpful.