The Full Frame

Many of you are probably thinking/asking how many megapixels are required for a 4×6 print? or a 8×10? or a 24×36?

Here is a small table of the minimum sizes (at 300dpi) high quality:

Here is a small table of the minimum sizes (at 150dpi) bare minimum:

As you can see, actual pixel count is fairly demanding for a “high quality” print. High quality meaning what is actually observed by the camera and not made up by some computer program. Typically computers are used with a algorithm called a Bayer Interpolation that will blend and “guess” the colors to make up missing information between colors and pixels when someone tries to enlarge them, so it is possible to get an OK looking 8×10 from a 5 MP camera, or an OK looking 24×36 from a 22MP camera. So keep in mind that if you are producing any of these sizes with less than the Megapixels listed your print is more a test of the quality of your computer software than it is your camera!

Also keep in mind that imaging sensors will see only one color and one intensity per pixel. So 1 px will see red at lets say a value of 210 (1 to 255 intensity, 16 Bit color). In order to record the real color emitted in real life you need at least 3 of these. Yes, just like your TV or anything else the camera will blend the 3 colors to create the real “observed” color. What is the caveat for this? Digital cameras (non-Foveon) only really “see” 1/3 of the claimed Megapixel value that they advertise (because they are using 3 pixels to record each “real” color) so that fancy 10 MP camera you own in reality only can record 3.3 MP worth of actual real life image, just enough for a high quality 5×7, the rest is blended and made up by computer software. This makes a strong case for the reason why REAL professional photographers still use film for all of their important work. This is because film CAN record a real color at each “pixel” which is still higher than digital (roughly 88 real megapixels for a 35mm piece of film).