The Megapixel Myth

Posted on August 2nd, 2008 | Permalink

In the world of digital cameras, megapixels appear to be the measuring stick. From a professional SLR to a cell phone camera, the more megapixels it has the better it is… right?

While this is partially true, there’s more to the story. Unlike the standard 35mm film of yesteryear, the “film”, or sensors, inside digital cameras are not all the same size. The bigger the sensor is, the more light it can capture. The more light it can capture, the more clearly it can distinguish between the different colors in the picture, leading to a sharper and more vibrant the image.

For example, while an $800 Canon Digital Rebel XSi and a $2,300 Canon EOS 5D both have twelve million pixels to work with and will give you an image that’s the same size, the image from the 5D will look substantially better because of its larger sensor.

The size of the sensor is usually not printed on the box, nor is it always on the manufacturer’s Web site. To find out the sensor size of a given camera, I use the camera database on www.dpreview.com, which has a massive catalog of digital camera specs, as well as reviews on many of them, as the name implies.

Sensor size aside, there are other costs that come along with with a large number of megapixels. Because the pictures you’re taking are bigger, the camera will usually take more time to process and save them, meaning you will be able to take fewer pictures in quick succession. You’ll also fill up your memory card and hard drive faster, and your pictures will take longer to copy from your camera to your computer.

While having more megapixels is certainly not a bad thing, the quality of digital cameras has reached the point that a 7 or 8 megapixel camera is sufficient for the casual shutterbug who doesn’t usually print things bigger than 8″ x 10″, and certainly enough for computer wallpapers and blogs.

So figure out your needs, do a little research, and if you don’t need to print things too big, consider dropping some megapixels and investing in a camera with a bigger sensor or a better lens instead.