What is a pixel? Pixels can have different meanings in different areas, but what we're interested in what pixels are with respect to digital photography and cameras.
The word "pixel" is actually a shortened combination from the two words; picture and element. Individual pixels are the tiny basic building blocks , that added up together, make a complete photographic image. Photographs are made up of thousands, to sometimes millions, of pixels, and cameras have sensors that have millions of light collecting pixels on them.
The definition of pixel is simple, but why is it important? Well, the number of pixels in an image can greatly affect the quality of that image. More pixels equals a higher quality photo.
To be honest with you, knowing what a pixel is really won't help you improve your photography. But, there is one thing you do need to know about: pixel count and the megapixel myth.
Certainly, with digital photography it's important to understand a few other photography definitions, but do you really need to understand how a pixel works? No.
Knowing a few digital photography terms will help you make better choices when comparing cameras and accessories and that's where the term megapixel myth comes in.
The megapixel myth came out of competition amongst camera makers. Each wanted you to think their camera was better than the competitions by bragging that there's had more megapixel and therefore was a better camera.
MORE MEGAPIXELS ALWAYS MEANS A BETTER CAMERA -----> WRONG !
For several years there was a race by camera manufacturers-and after that smartphone makers-to jam as many pixels as they could onto a sensor, even if that diminished the quality of the images. In addition to the number of pixels on a sensor, there are other important factors determine the quality of a photo that comes from any given camera sensor. They include
A megapixel is one million pixels. A digital camera sensor that has an 8.2 megapixel sensor has about 8.2 million or 8,200,000 pixels. Technology has change things dramatically. One of the first digital cameras I held in my hands was .03 MP (megapixel camera).
Is a 16 megapixel camera better than a 12 megapixel camera? Generally it usually is, but not always. The actual size of the individual pixels matters. Bigger individual pixels are better at collecting light.
How closely they are spaced together matters. If your sensor has a lot of space in between individual pixels, then the resolution of your camera will be too low.
Here's the deal: There are too many variables to make a hard and fast conclusion about image quality based solely on the number of pixels built onto a sensor.
Here's what I mean.
It can be confusing because we also refer to those individual points of light on an LCD or TV screen as pixels. What is important is that you don't fall into the trap called that megapixel myth: "More Megapixels Must Mean Better Photos."
With respect to a digital camera sensors, the term pixel usually refers to a photosite which is a combination of red, green, and blue elements that combine to form one color point. There are 2 different basic structures used when sensor manufacturers build sensors for cameras.
It's not the definition of what is a pixel that matters. It's overall size, the width and length of a sensor, is the most important factor in terms of image quality. Also important is the size of the individual light-collecting photosites, how close they are to each other, as well as the camera's internal processor that converts that light information into a viewable image.
See the diagram below to make more sense of this. The bigger sensor has more light collecting surface, even though these two sensors have the same number of pixels.
It's 2019. This post has been updated and it's not a far cry from reality to say that all new cameras have plenty of pixels to satisfy your every pixel popping need. When you're choosing a camera. you need to be guided by looking at your shooting style and how you're were going to use your photos afterwards.
Previously, if you were using your photos just for the internet or sharing with friend via email, a low megapixel count was adequate. If you were printing to a nice small snapshot size you needed more megapixels to get a decent quality.
Large poster-sized prints required image files from high megapixel cameras. Not any more. Even budget digital cameras have 8 megapixels or more. If you fill your frame with your subject, you've got plenty of pixels to produce really good quality.
Here are more questions and answers about digital camera pixels:
Pixel pitch is the distance from one pixel to the next. Essentially, it's wasted space that doesn't help in capturing and recording the light waves. Camera sensors that pack the light collecting pixels in closely are more efficient at gathering those electrons form the light passing through your camera lens.
Pixel pitch is measured microns (µm). The closer the pixels are squeezed together the higher the resolution.
One common questions is how many pixels is a megapixel. The prefix "mega" means million, so the answer is 1 million pixels. A camera with a 10 megapixel sensor then, has 10 million pixels to capture the light as it enters the camera.
There are two light sensitive diodes on each pixel. Canon made it famous when it was implemented on the Canon 70D. Samsung used it on the Galaxy S7. Dual pixels make for better and faster focusing and Samsung used it for faster focusing and that bokeh effect.
Cameras on cell phone are known for slow focusing, so a fast focusing cell phone camera is a great step in the right direction.
What should you look for when comparing camera sensors and pixel count? There are three primary ways to find out if the camera you considering has the right sensor for your needs.
First, I confess that I have spend many hours with method 1. I actually enjoy reading the technical reviews, but that's no surprise, I've been a camera geek since middle school. I started out buying (and then selling) used film cameras and other camera gear on eBay, but not so much anymore.
No, I find the most useful information about photography equipment (and many other products I buy) from photographers who have purchased and used the camera already. These are everyday people like you who want to get the right product, at the right price.
The feedback from regular folks like you and me is very valuable. The readers of the Better Digital Photography Tips website know I like to find practical answers, not necessarily the most technical.
When people are searching for a definition of what is a pixel or an explanation of pixel or the definition of megapixel, it is usually because they want to make an intelligent decision on comparing digital cameras and choosing the right one.
I hope this article was helpful. Fore more on related topics see the links below my signature. To search for any topic on this website use the search box below.
ABOUT BRUCE LOVELACE
Bruce is the publisher of this website. He is the author of the book "Improve Your Photography Instantly." Read more on Bruce on his Bio Page. He's been known as The Traveling Photographer ever since 1994. Or read more about this website.
View some of Bruce's photos on Instagram. Visit the Facebook Page. Watch him on YouTube. Bruce runs photo workshops for kids and adults, and provides one-on-one photography coaching.