I mean, do you even know what a megapixel is? That's what I thought.
The answer to that is actually fairly simple: picture data is made up of individual dots. With film, lower film speed means a finer grain (or more dots) and the higher the film speed the fatter the dots. Now with digital, the sensor captures information on pixels. A megapixel is just a measurment of the number of dots on the camera sensor. The more dots, the sharper the image -- so more megapixels means a better camera, right?
Unfortunately, not all megapixels are created equal.
For example, look at my smart phone camera: I have an HTC, and it has a 5 megapixel camera, which it says is a resolution of 2592x1552. That means the image size is 2592 dots by 1552 dots, mathematically calculated as 2592 times 1552: 4022784, which they round up to 5 million, otherwise known as 5 megapixel.
Now, when I shoot professionally I use a Canon Rebel T3i. It's an 18 megapixel camera, with a maximum resolution of 5184x3456. Compared to the phone camera, the resolution of the canon is 3.6 times greater -- but the resolution is only about double. Why don't they line up?
The answer, my friends, is easy: it's all about sensor size. When you're shooting in digital, the key to image quality is not just megapixel, but also sensor quality and size, and when you're out there shopping for a camera you need to consider all three.
Now, if you're only going to be using this camera to create online albums or print some small photos for around the house, then a good camera phone or a point and shoot is really all you need. If you remember, in an earlier blog I talked about the camera in the latest iPhone. It really is fantastic for something with such a small sensor, and I've read that within the next five or ten years the point and shoot camera will become obsolete; any smaller camera will be the one you find in your phone.
Now, that camera phone will do a fine job if you're just looking to post photos on Facebook, but you'll really need a DSLR if you want to enlarge your work for a poster or what have you.
Take, for example, the photo below. It's a photo I took on vacation in Alaska last year, and it's hanging on my wall as a 12" by 36" canvas print. Try doing that with your iPhone!