There are many myths in technology many driven by marketing but all perpetuated by lack of knowledge. One of the most common ones and possibly among the most damaging to a consumer’s pocketbook is that when a camera is purchased the more the megapixels the better the camera. That is patently wrong and demonstrates a lack of understanding of basic photography principles.
What is a megapixel? Simply put it is a collection of a million pixels. A pixel is a unit of light capturing surface on the camera’s sensor. How many megapixels one needs? There is no clear answer to that but for most consumers ten megapixels are more than enough. For professional photographers that need to either print very large images or to crop to a very small portion of the image megapixels become more important but only if paired with other critical components.
An often overlooked component is the size of lens (or glass), the average cell phone today has digital cameras with high megapixel counts and yet does not produce great quality photos when printed. Interestingly when viewed on a PC the photos look fine. Why? Because even an HD display is actually just over two megapixels! A resolution of 1080 is 1920 x 1,080 or 2.1 megapixels (2073600 to be exact). The average 4X6 photo is printed at two megapixels whereas the average 16X24 picture is printed at 12 megapixels! It is obvious that the consumer grade camera does not need a high megapixel count.
When spending money on a camera then the critical components are the size (in diameter usually in millimeters) of the lens; the speed of the shutter; the size of the sensor; and if the camera uses mirrors or not. Prisms are preferable to mirrors. Most modern cameras are at least ten megapixels so it would be hard to find a camera that does not have a high enough count to print even 16X24 pictures!
The most commonly available digital cameras with interchangeable lenses are made by Nikon or Canon. Kodak is no longer a serious contender. Professional photographers tend to use high end Canons and often Pentax or Lika. Interchangeable lens cameras (often referred to as DSLR) allow the use of different lenses to better match the conditions. The tend to start at around $800.00 with a single basic lens.
Point and shoot cameras are more appropriate for the consumer photographer. Their lenses are fixed and usually provide zoom capabilities. Digital zoom only cameras should be avoided as the same results can be achieved with software. These cameras even if they have the same megapixel count as DSLR cameras tend to produce inferior pictures because they have smaller lenses and smaller digital sensors.
It is not the count of megapixels that is most important in a digital camera (but it is a consideration).