I get a bit confused with some of the numbers and how they work with prints as compared to with the monitors etc. I have a lot of experience with photography but am a little new to all this digital stuff. Maybe I should take a seminar on it but most of my experience thus far is self taught. Here is how I understand the situation of the display of the images.

First my notebook has a 1024x768 screen and displays images, as I understand it, around 72ppi.(dpi?) Anything larger than that is lost in the resolution of the monitor. Further, Monitors don't really rely on the 72ppi or 300ppi etc. They are what they are. They won't display anything more or less. What your monitor does display is a certan number of pixels, rows x columns. or, again, in my case, 1024x768. There may be some who still utilize monitors with 800x600. I would venture a guess that 640x480 is probably non existant or not common. When I design my web pages,

http://members.aol.com/wmas1960/homepages/Vegas1.htm

for example, I design them at 750 wide. This way they will fit on almost all screens. Further, 750, I have found, is about the limit of a printed page on Internet Explorer. Therefore if someone wants to print the page out it will fit on their 8.5" wide paper.

Some of the megapixel ratings....

1024x768 = 786,432 pixels or a little over 3/4 of a megapixel.

2048x1536 = 3,145,728 pixels or 3.145... megapixels.

I am not sure what the dimensions of a 5mpxl image is but it is in here somewhere. I use a Nikon D100 now days and the images it gets are,

3008x2000 = 6,016,000 or just over 6 megapixels. Incidentally, a full size image here with minimal compression is, 2.256meg

the 3mpxl image is, approx., 1.06meg, and a 1024x768 image can be expected to be around, 670k

The images that I tend to use, which are specifically sized and compressed for web use are,

at 39k and the photo at bottom of the UP SD70M is about 97K