It is important to set your camera for the highest resolution possible. This will save the fewest number of pictures on your memory card. Many cameras have settings such as “Standard,” “Normal,” “High Quality” or “Super High Quality.” Check your manual to determine the specific resolutions these terms represent. Depending on your camera, the resolution settings could range from 800 x 600 (0.45mp) (an image with 800 pixels across and 600 pixels down) to 5616 x 3744 (21mp) (Megapixel 1 Megapixel = 1,000,000 pixels or actually 1,048,576 in a computer. See FYI Below.) A 800 x 400 or 1024 x 768 image is fine for viewing on a computer monitor or for web use; 4096 x 2731 (12mp) or higher is better suited if an image is headed to a printing press. With a setting that allows more photos to be saved on the memory card, your pictures will be smaller and may be too small to be reproduced suitably for a printed publication.
Another way to understand resolution is in its relationship to image size. If a 72 ppi image is 17.7 x 14.2 inches on your monitor, it will be just 4.3 x 3.4 inches when sized for printing at 300 ppi. So, if you submit a 72 ppi image to use in a publication, the largest size at which it should be printed will be about one–fourth of its original dimension.
Tip: With digital photography it’s important to move in close to your subject. Cropping the important feature from an already small image leaves only a few pixels per inch.
FYI! The reason that on a computer a Mega either byte or pixel is 1,048,567 is because computers use binary to do everything and 10 base10 is 1010 base2 (binary) (that’s one in the eight digit and one in the 2 digit or 10 base10.) not exactly an even number. Early computers used 8 bits to create one byte 11111111 base2 which is 256 base10. By using 4 bytes to a word you get 1024 as the base even number in computers. So one Kilobyte is 1024 bytes and one Megabyte is 1024 Kilobytes so one Megabye or Megapixel is 1024 times 1024 or 1,048,567 bytes or pixels. Is your head spinning yet?