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Digital Cameras: How Many Pixels Do I Need?

2008-06-13来源:

With the bewildering number of digital cameras on the market, it's increasing difficult to know where to start for your first purchase. One of the major determining factors of the price of a digital camera is the number of pixels. Nowadays, even 5.0 megapixel cameras are affordable, even for casual snapshots.

But is bigger always better?

Higher megapixel cameras do have some drawback. The first, and most obvious, is price. A basic 5.0 megapixel camera currently runs between $200 and $300. A 1.2 megapixel camera can be had for less than $50. Storage for those large pictures will also cost you more. A 32 MByte memory card will hold around a hundred 1.2 megapixel pictures. This drops right down to around 60 pictures for 2.0 megapixels and to around 40 pictures for a 3.0 megapixel model. One other consideration, not often mentioned, is that a higher megapixel camera has to do more work to compress and store images, leading to longer waits between picture shots and viewing.

Before you rush off and spend $300 for a camera, consider what you will be doing with the pictures. Are you viewing them just on your computer? Sending them as email attachments? Printing them on an existing inkjet printer? Having them professionally printed?

The larger the number of pixels, the larger the file size. An important consideration if you are emailing them as attachments. The following chart shows sample file sizes, typical resolution and maximum print size for different pixel counts stored as high-quality JPEG files:

Pixels - - - File Size - - - Resolution - - - Print Size

1.2 - - - - - 480k - - - - - 1152 x 864 - - - - - 4 x 6 inches
2.0 - - - - - 980k - - - - - 1600 x 1200 - - - - 5 x 7 inches
3.0 - - - - - 1.2M - - - - - 2048 x 1536 - - - - 10 x 8 inches
5.0 - - - - - 2.3M - - - - - 2592 x 1944 - - - - 11 x 14 inches

Most computers will only display the 2.0 megapixel image (at most) without scrolling, so you may find yourself resizing all your pictures - or not using the maximum resolution of your camera - if you have a 5.0 megapixel camera.

Only ever print pictures at 5 x 7, or only view them on a computer? Then a 2 megapixel may be enough for now. The prices will be lower next year if you want to upgrade later.

Obviously, the higher pixel cameras do have some advantages, especially when it comes to cropping and editing - and you know the salesman will want to sell you the best camera in the store - but I hope this information will help in making an informed decision.

Marty is the editor of a number of websites including http://1PhotoProducts.com and http://discountgolfequipment.us