What is a megapixel and why is it important?

If you've recently purchased a new camera, smartphone or action camera, you've inevitably come across the term 'megapixel', or MP for short. But what is it and why is it so important in the world of photography? We explain everything to you in this guide.

What is a megapixel?

Megapixels are the number of pixels you can capture in a photo. A pixel is the smallest unit of information in digital images. It is a combination of red, green and blue dots called “sub-pixels”.

The number of pixels determines the resolution of an image, also called size or scale. A high megapixel camera can in theory not only capture a detailed photo, but it can also help you crop your shot without losing clarity.

Does more megapixels mean better images?

While megapixels are a big part of camera specs, they don't necessarily make for the best photos. A camera with fewer megapixels can produce better images than a camera with higher numbers because each pixel is larger. This means more light is let in and the image is brighter.

When looking at the specs, be sure to check more than just the megapixel count. Other factors play a role in image quality, such as sensor size and lens quality.

Why is megapixel important in mobile phones?

On a phone, this is exacerbated because the device's form factor limits the size of the lens and the amount of light it can absorb. Since you'll probably want to share these images on social media, having too many megapixels can actually be a downside.

If you try to post a high quality image to Facebook, it will appear pixelated and blurry. This is because Facebook uses a lower resolution when you upload a photo, so it loads quickly and everyone can see it. For the best quality images to appear as expected, you will need at least an 8 megapixel camera.

You can see examples of the above in our guide to the best camera phones, which includes a number of handsets with lower megapixel main sensors.

What is the best resolution for videos?

Megapixels work slightly differently for videos. For videos, you want low resolution. When capturing video, you need to consider the megapixels used for each frame. If you have too many megapixels, you will end up with poor quality video.

It's important to remember that more megapixels doesn't always mean better quality. If you're not sure what to look for when buying a new camera, keep these things in mind. Higher resolution isn't always better, and you don't necessarily need the highest number of megapixels to get good results.

What is the difference between a megapixel and a resolution?

Megapixels and resolution are not the same thing. Resolution measures the number of pixels in an image – the total number of dots that make up the image. Megapixels measure the size of each pixel – a million sub-pixels make up each pixel. Image resolution and print resolution are different things.

Resolution is about how much information you need to work with, while print resolution is about how much information you can actually use. Print resolution is measured in dots per inch (dpi) and tells you how many dots of ink can be applied to a sheet of paper within a one-inch radius. The higher the dpi number, the more detail your printed images will have. Digital camera images are created at a specific resolution. There are a few standard resolutions, but most cameras allow you to change the settings to suit your needs.