I've overheard a lot of questions lately about image sizes, resolution, dots per inch, pixels per inch, megapixels... it reminds me of when in Back to the Future, Doc Brown realizes he needs 1.21 gigawatts for the flux capacitor..
""1.21 GIGAWATTS!?! 1.21 gigawatts! Great Scott!!!"
Well you dont need 1.21 gigapixels for a nice 9 X 11 inch calendar picture, but you do need alot of them critters. A whole lot more than what it takes to make a really nice picture on your monitor. You see your monitor can produce any one of 16 million colors in any single pixel.. and if you have a screen resolution of say 1024x768, and your monitor is about 14 inches wide, thats 1024/14 = about 72 pixels per inch, or 72 PPI. This is an important measurement- PPI. A desktop screensaver image of a 70 Challenger that is 1024x768 looks fantastic on the monitor and it has a resolution of only 72PPI. But there is a big challenge when you go try to get an 8x10 photo of it. See a printer requires about 4 times more dots per inch to achive what lookes like quality to the eye.
The standard for high quality prints is between 250 and 300PPI. Most high quality printers are going to try and squeeze between 200 or 300 of the Challenger's pixels into each inch of printed paper. Well you only have 1024 pixels to work with. Suddenly that really nice looking image that was 14 inches wide on your monitor will now only be a high quality image if it is 1024 pixels / 300 PPI = 3.41 inches wide!
So what if you want a print that is 10 inches wide? On one hand you can print it at 102.4 PPI which will be about 1/3 the quality you would expect or you can get yourself another picture that is between 2500 and 3000 pixels wide, and when you print it between 250 and 300 PPI is will end up at 10 inches with perfect quality.
How to get those pixels? You need a camera capable of producing image sizes that are in the 2500 range. see the chart here:
http://www.microsoft.com/windowsxp/using/digitalphotography/learnmore/bestquality.mspxa 4 or 5 Megapixel camera gets you there, a 3 Megapixel camera really cannot create a high enough resolution image for a quality 8x10 print. And the Calendar images are supposed to be in that range - I think 9x11 is the working size. So you need to get those pictures to be at least 2000, preferably 2200 or 2500 pixel size.
