When I first start shooting with my new digital camera I didn’t think twice about image size. Then, I tried to print dozens of digital images of my delicious baby daughter, and I realized that size matters.
Image size is an important element in digital photography. Simply defined, image size is the measurement of your original digital photo file in pixels and DPI (Dots Per Inch). You might also see image size referred to as PPI (Pixels Per Inch). If you know what a pixel is, you will be better able to grasp the size concept.
Pixels are the small dots that make up digital images. DPI refers to the number of dots (pixels) per inch. This information comes in handy when you are trying to print an enlargement of a smaller digital image. When it comes to image size versus print size, the general rule is that image size should be at least the size of the print you want multiplied by 300. For example, if you want to order a 4×6 print, the image size should be 1200 pixels (4 x 300) by 1800 pixels (6 x 300) at 300 DPI. If your image size is half of that (600 by 900), then your 4×6 print will likely be distorted (or pixilated).
To avoid printing pixilated shots you need to decide in advance if you are more concerned with image quality or room on your memory card. Once you determine which is more important, you can set your camera to take large or small size photos.
Choose the latter if you want to store more photos on your memory card. Choose the former if you know that you want to print enlargements of your images. Also, if you enjoy making photo books, then keep the camera setting on “high” for higher quality images. Though, keep in mind that with larger image sizes you will not be able to store as many photos on your memory card at one time.