If you are reading this then there is a good chance that you are looking to buy a new camera. You must have asked yourself the how many megapixels question. New digital cameras support and ever growing number of megapixels, the question is do you really need so many pixels?
The race for more megapixels begun when the first digital camera was introduced and it is not stopping. New affordable cameras with 12 megapixels or 16 megapixels are already on the market. Manufacturers are trying to convince consumers that the higher the megapixels number the better the camera is. While this might be true to some extent the main reason behind that marketing campaign is to obsolete whatever camera you own and convince you to buy a new one, better one, with more pixels. Similar to the early megahertz computer craze the megapixels serve as an easy number to compare cameras by.
But when it comes to actually using the camera the importance of the number of megapixels is much more complex. And as the old saying goes, more can sometimes be less. For example when you buy a new camera, for example your budget is limited so maybe you could be a 10 megapixel camera but have no money left for a big memory card, a carrying case and a spare battery or instead you could buy the cheaper Canon PowerShot SD1000 7 megapixels and also spend on those needed accessories. After all what good are megapixels if you do not have a memory card with enough capacity to store them on?
There are a few factors you should consider when choosing the number of megapixels that is right for you. Try to figure out what will the camera usage be. For example you need a high megapixels camera if you intend to print enlargements or if you will need to zoom in and maintain fine details in small area out of a big digital photo. However if you plan to simply view your photos on your computer screen you do not need many pixels at all. In fact you will be surprised how low the number you need really is. Your computer screen resolution which is in most cases around 1024X768 translates to 1024X768 < 1 megapixels when watching a photo in full screen mode. Yes that was less than 1 megapixels.
When it comes to printing you could use the following method to calculate how many pixels are needed. A good print quality is about 300 DPI – dots per inch. If you do the math the following are the needed megapixels rounded up for different print sizes:
page 4X6 2MP
page 5X7 3MP
page 8X10 7MP
page 11X14 14MP
page 16X20 28MP
page 20X30 54MP
So if you bought the Canon PowerShot SD1000 you can print good prints up to 8X10 which is more than enough for almost all users. In fact for most users that view their photos on their computer screen and occasionally print a 4X6 photo a 2 megapixels digital camera is what they need. Digital camera prices go up as the number of megapixels goes up. There is a certain megapixel number sweet spot which is where the buy is most economical. The high end cameras with the highest megapixels are very expensive while the current standard number of megapixels is cheaper and probably more or less the same as lower megapixels were a year or two ago. In other words the price for the cameras does not change much if you plan to buy the popular cameras but you do get more pixels for the buck. For example the Canon PowerShot SD1000 sports 7 megapixels sensor and can be bought for about $150-$200. A few years ago $200 would hardly buy you a 3 megapixels camera.
This article and more are from Danette Mckay who is an expert in his field. canon powershot sd1000 7.1mp digital elph camera with... provides more in depth information.