[Doctordestiny]

Originally Posted by MickMcGeough

Generally, a picture's resolution is proportional to the size of print you can use, so yes a 200x400 picture could make a print double (well, technically 4x) the size of a 100x200 picture.

# of pixels (resolution) is one of many things that affect the file size (bytes). Color depth, compression level (usually "quality" or "definition" setting on your camera), color range, and more determine the actual size. Do not use the file size as a way to reliably determine picture quality or print size.

Detail is a pretty vague term but in general yes, a picture with lots of contrasts and colors will result in a bigger file than a picture with the same settings of a black wall, for instance.

Not bytes at all, and not pixels by themselves. Every camera is wildly different. I went traveling with a 3 megapixel Canon that prints 20"x30" prints that look absolutely stunning. The same size print from my old 6 megapixel HP look awful. The Canon pictures' file size and resolution are considerably lower than the ones taken from the HP but the Canon pictures make much better quality large prints.

Any reasonable quality new-ish (3+ megapixel) camera should be good to at least 8x10. Higher than that, you'll have some prints made and see for yourself.

Also check digital camera forums to see what kind of experience people with your particular model have had.

Wow, what a good response. Thanks, Mick.