Megapixels - just how important are they when buying a digital camera? When you are buying digital, megapixel is almost universally the first feature listed, and many times the digital megapixel count is used in the camera name. For instance, you might find a Canon PowerShot SX230 IS 12-megapixel camera on sale. Notice that the "12-megapixel" is included in the camera title? We are actually conditioned now to look for this feature first.
Just how important is the number of pixels?
There are a few articles floating around with the title "Megapixel Myth." The understanding is that we have been sold a false concept, that being that the most important camera feature involves the number of pixels, or digital megapixels, on the image sensor.
In the beginning, when digital imaging was young, the first cameras made with sensors larger than one megapixel were available. At that time, a Nikon/Fujix digital camera with a 1.3-megapixel sensor would set the buyer back close to $10,000. There were not many of those digital cameras being sold. The interest was high, but so was the price tag.
Then, less than a decade later, along came the Canon Rebel 300D. The year was 2003. It was not just a compact digital camera either; it was a digital SLR that had a price tag of $999. This 6-megapixel camera broke the $1000 barrier for the first time in digital SLR camera history. Yes, it was a long way to go in a decade. Now, cameras are sporting anywhere from 10-megapixels to 18-megapixels on average. This includes compact digital cameras as well as digital SLRs.
Not all pixels are created equal
By definition, a pixel is a light-capturing mechanism. The name is short for "picture element." And now that most photographers are shooting digital, megapixel is a very important part of their camera. A digital megapixel is equal to 1,000,000 pixels. Thus, if your camera had an image sensor that had 1,000 pixels across and 1,000 pixels down, it would be a 1-megapixel sensor. But there are literally no square sensors. An image sensor for a Canon 30D 10-megapixel camera would measure about 3504 x 2336 in pixels.
In contrast, an 18-megapixel camera, such as the Canon Rebel T3i or 7D, has a sensor that measures 5184 x 3456 in pixels. While this truly seems like a major difference, you have to consider a couple of things before deciding which camera will give the better image. The first thing to consider is the quality of each pixel. It is possible to get a higher quality with less pixels if the technology involved in creating the smaller sensor is better.
Secondly, how large is the sensor? The sensor in a point and shoot digital camera is much, much smaller than a sensor in a DSLR camera with the same digital megapixel count.
The larger the sensor (in physical size), most likely, the better the images.
Megapixel print size
This is where the argument gets a little fuzzy for some folks. Do you really need a huge number of megapixels in order to make a huge print? If you set your printer output to between 120 and 160 dpi (dots per inch which is virtually the same as pixels per inch), you can print a photo that measures 24" across from a 6-megapixel digital camera. If you are planning to print images that are larger than 24", you can still do it with some software adaptations. However, consider this.. most people view large prints from far away.
They will not be examining the picture with a magnifying glass. Your 6-megapixel photos will look great. Finally, think about the photographer-camera relationship rather than the number of pixels. If the photographer has a pretty good skill set, he or she can take great photos with any camera, but if the photography skills are not there, no amount of megapixels will solve the poor image output.
The bottom line is that when thinking about buying digital, megapixels are important, but many other features and skills must be part of the package. Don't just make your decision based on one feature.