One of the confusing things for many in choosing a digital camera is deciding how many megapixels you should look for. The answer depends on what you plan on doing with the finished pictures.
First, you need to understand what a pixel is. In terms of digital prints, a pixel simply means a dot of color that makes up the image. A megapixel is equal to one million pixels. Generally speaking, more mega-pixels gives you more flexibility—you can print at larger sizes and crop without losing too much quality.
The easiest way to decide what to look for is to know what size prints you are likely to print from your camera.
A two megapixel camera is fine for those who don’t plan on printing photos but rather just post them on the internet. A small print, say 4 x 6, will print acceptably from this camera.
A 3.2 megapixel camera will enable you to produce good quality 5 x 7 prints and fair quality 8 x 10 prints. When you reach 7.2 megapixels you can print out excellent quality 8 x 10 prints and acceptable 11 x 17 prints and a 15.1 megapixel camera will allow you to print out high quality 11 x 17 prints.
Most people find a camera in the 7.2 mega-pixel range to be the best choice. The quality of both 5 x 7 and 8 X 10 prints is very good yet the files on your computer are not so large you need worry about not having enough space.
Any camera over 15.1 megapixels is unnecessary for all but advanced amateurs and professionals in photography; even then, only those who have need for poster-size prints find that many megapixels worth the money. Most freelance photographers find 7 or 10 megapixels to be sufficient for excellent-quality prints.
Here’s how you calculate the number of megapixels you’ll need for a printed photograph:
Determine the physical size of the print you plan to make, such as 4 x 6 inches, 8 x 10 inches, etc. Then, multiply the width by 300, and the height by 300, which will give you the size in terms of pixels. (300 ppi — pixels per inch — is recommended for good-quality prints.) Therefore, an 8 x 10 inch print would be 2,400 x 3,000 pixels.
Multiply the width (in pixels) by the height (in pixels). So for that 8 x 10 inch print, it would be 2400 x 3000, which equals 7.2 million pixels.
Divide the result from step 2 by 1 million, and you have the number of megapixels you need to make a good print. In this case, the minimum resolution you’ll want your camera to have is 7.2 megapixels.
The choice is yours. Look to what you plan on doing with your photos and then decide. In most cases spending the money for increased optical zoom and lower mega-pixels is the best choice.