Alrighty, folks. This post is going to get a bit technical.
Nearly everyone has heard of megapixels and, depending on who you speak with, you either have been told more megapixels on a camera are better or maybe you've been told once you reach a certain point megapixels don't matter anymore.
Well, it depends on what you're using the camera for. If you're just out to take 5x7 photos of your children, you probably won't need a camera more than six megapixels. Phones nowadays have more megapixels than that.
So what's the deal? What's a megapixel? Why are they a thing?
Whoa, whoa ... slow down.
Let's start with: What's a pixel?
A pixel is a square that is assigned a certain color in a digital photograph. Let's say we have a green pixel and then next to it we put another pixel that is a slightly different variation of green. If we keep adding pixels next to each other, we can eventually create an image.
All the little squares add up and when you step back pixels can become an image. That's how Digital Single Lens Reflex, point-and-shoot and phone cameras record digital images — with pixels.
Alright, so what's a megapixel? A megapixel is one million pixels.
That's a lot. It's especially a lot when you say a camera has 10 megapixels or more. That's
10 million pixels.
For the professional photographer, more megapixels are always better. More megapixels means more detail in your photographs. More megapixels means more room to crop your photograph into a smaller image and still have A LOT of detail.
Let's say we have a 22 megapixel image with a person who's really far away in the photograph. If we want, we can open the image in Photoshop (or another image editing program) on a computer and crop the image so that person appears a lot bigger. The image is 22 megapixels, so there are a lot more pixels to work with and therefore when we crop the image the person will have a lot of detail.
Adversely, if we took the same image but it was shot at two megapixels, when we crop the image down, the person in the photograph will have barely any detail at all. In fact, that person will look more like pixels than a human being.
The only downside to having more megapixels is file sizes. Whether you shoot in RAW format or JPG on your camera, more megapixels means more hard drive space is required to be able to store these photos. Thankfully, hard drive space is fairly cheap to come by. You can go out and buy an external drive for an affordable cost most anywhere these days.
Cell phones have really upped the ante when it comes to megapixel count because when people take images on their phones they want to be able to zoom in and see the scene they just captured.
Some phones go all the way up to 15 megapixels. For a phone, that's a bit overkill and it will more likely than not show the limitations of the phone's camera.
For DSLR users, 15 megapixels is a starting point these days. Many DSLRs have image sensors that shoot 18 megapixels or more. My Canon 5D Mark iii has a 22-megapixel image sensor.
Also, if you've been keeping up with news in the camera world, you may have heard about Canon's new 5Ds and 5DsR DSLRs. These cameras boast a 50-megapixel sensor! You can put up crystal clear images on a billboard with that many pixels.
Nikon also has a large megapixel camera with their D800 model at 36 megapixels.
Megapixels aren't everything, but depending on what you need to use your camera for and if you have the storage means ... more is generally better.