Megapixels and Resolution

How many megapixels should I look for when I’m shopping for a new camera? Seems to be a fairly common question these days. More is better, right?

If you believe the advertising and sales people at most camera stores, it would be easy to get that impression. Most of the magazine reviews will indicate that increased pixel count is an “improvement” when comparing the previous model with the new and improved version.

Contrary to what all these “expert sources” may be saying, more megapixels don’t necessarily equal better images. It really depends on what you plan on doing with the images after you capture them.

If you take family and friends snapshots or intend only to use your images for a web site you really don’t need more than about six megapixels. You probably would not notice the difference between three or four megapixels and six. You would only notice the difference in a small percentage of your images if you compared them at 100%. But, you would never see the difference on a web page or in standard prints.

You wouldn’t see a difference even with 8X10 prints. Even professionals printing to thirty inch wide prints get excellent results with six megapixel files. The real world doesn’t always correspond to advertising copy.

Some other things not talked about much by sales people, or advertising copy writers are things like color balance and ease of use. They would rather have you believe myths like ten megapixels have a lot more resolution than six. Actually the difference is minimal. Doubling resolution requires a four time increase in pixels. So, to double the resolution of a six megapixel image would require twenty-four megapixels.

What about after you take the picture? More megapixels take more room on your memory card. So that means buying more or larger cards to deal with the larger images. Then your computer has to deal with the larger files in several ways. Just as the card size must grow, you can’t store as many images on your hard drive. That means you need to upgrade the on board drive or start adding drives. This applies to the drives that you back up to as well.

Another area not discussed is the additional load on the processor. PhotoShop or the imaging software you use won't seem as snappy with larger image files. If it seemed slow before, buy a new camera that makes huge files, and your computer will slow to a crawl.

So, after buying the upgraded camera, you now need to invest in more hardware and working on your computer becomes torturous because of the additional processing time. Worse, you can’t see any difference in your prints or that web site you work on. But, cheer up. You can brag to all your camera friends that you now have the latest _______ (fill in the blank) and they will all be envious. If they only knew....