A group of multi-ethnic people at varying resolution qualities.

What is Camera Resolution?

Among the many variables you will consider when purchasing a security camera, the camera’s resolution is definitely an important factor. After all, a camera’s resolution more or less determines the quality of the image the camera produces. But how do manufacturers determine a camera’s resolution in the first place, what benefits are there to higher resolutions, and what security camera resolution is the best? This article will hopefully make this topic a bit clearer for you.

How Camera Resolution is Determined

You’ve probably seen a camera’s resolution expressed with as 4K or 2MP, but what do these mean and what are they measuring? Simply put, a camera’s resolution refers to the size of the image a camera generates and is measured in pixels. The shorthand “MP” describes a “megapixel”, which is a unit that equates to a million pixels. A camera’s total resolution is devised by multiplying the amount of pixels a camera generates on the x-axis, with the amount of pixels it generates on the y-axis. Think of it as the “area” of the image that is calculated by multiplying the length times the width.

For example, a camera’s resolution could be 1800 x 1200, meaning the image is 1800 pixels across, and 1200 pixels high. If you multiply these numbers, you get 2.16 million pixels in total, which, rounded down, comes to a camera resolution of 2 megapixels or 2MP. As a general rule, total camera resolutions are often rounded up or down to a whole number for marketing purposes. One camera can have a total resolution of 1.8 million pixels and another can have a total resolution of 2.2 million pixels, but both will be referred to as 2MP cameras. Got it?

What is HD, Full HD, 2K, and 4K Resolution?

The higher end range of camera resolutions usually end up in the HD, Full HD, 2K, or 4K range.

  • HD (1280 x 720, 720p, 1MP): On the lower end of the scale is HD or high-quality footage, which is normally an image that is 1280 pixels across and 720 pixels high. This resolution can also be called 720p. The total resolution of 1280 x 720 is 921,600 pixels, which would make cameras of this quality capable of 1MP images. For basic security purposes, this is a great resolution to start off with.
  • Full HD (1920×1080, 1080p, 2MP): A resolution is considered Full HD when it is 1920 pixels across and 1080 pixels high. This is why Full HD resolution is sometimes referred to as 1080p. If you multiply 1920 by 1080, you get about 2.07 million pixels, which mean an HD camera can also be called a 2MP camera.
  • 2K (2560 x1440, QHD, 1440p, 4MP) : A 2K resolution refers to an image that has around 2000 pixels horizontally and is sometimes called Quad High-Definition. This is because the the vertical resolution is four times higher than 720p. The most common ratio for a 2K resolution is 2560 x 1440, which is why 2K is also called 1440p. The total resolution sum of 2560 x 1440 is 3,686,400 pixels, which classifies cameras of this quality as 4MP cameras.
  • 4K (3840 x 2160, UHD, 2160p, 8MP): 4K resolution occurs when an image has a width of about 4000 pixels and is sometimes referred to as Ultra High-Definition. Because it has a vertical length of 2160 pixels, it is also called 2160p. If you multiply 3840 by 2160, you get around 8.29 million pixels, and thus, a 4K camera records at a quality of 8MP.
A chart that compares HD, Full HD, 2K, and 4K image resolutions.

A visual comparison of higher end image resolutions.

What Is the Best Security Camera Resolution?

Now that we have a broader understanding of camera resolution and what it entails, we can discuss what camera resolution will work best for your purposes. “But wait,” you might ask, “Isn’t the best camera the one with the highest resolution?” Well my hypothetical friend, in some cases that would be correct. Security camera technology has come so far these days that even a high-resolution camera won’t break the bank. But still, you might want to consider some factors before deciding on your unique security solution.

  1. Budget: As mentioned previously, high-definition cameras no longer cost an arm and a leg to purchase. However, consider that the higher the resolution, the more expensive the camera will be. Take this into account when strategizing.
  2. Location: What kind of coverage do you need for your security system? For example, if you have a wide open area that you want to record, then it may be best to invest in a single high-resolution camera that can survey what you require. However, if you need coverage in multiple distinct locations it may be wiser to invest in several lower resolution cameras to build a network that fits your needs. Also keep in mind that higher resolution cameras (like 4K) need more light to produce stable images. Features like infrared-technology helps assuage these concerns, but it’s good to keep this in mind if you plan on recording in darker areas.
  3. Purpose: Perhaps one of the biggest factors that will determine the right camera resolution is the purpose of the security unit. If you plan on recording in a parking lot for example, and need a camera that has License Plate Recognition features, it is not recommended to use a resolution much higher than 2MP. This is because a higher resolution would slow down the camera’s ability to capture and process vehicle images quickly and efficiently. But also consider if camera zoom features are important to you (for facial recognition purposes let’s say), a higher resolution camera works best. Image quality degrades if low-resolution footage is enhanced, but because high-resolution footage has higher pixel density, this problem is avoided.
  4. Storage: Keep in mind that higher resolution cameras, while offering better image quality, produce massive digital file sizes that need to be stored and processed effectively. Lower resolution cameras generate smaller files and require less bandwidth to process, and can record at a higher frame rate. If you invest in cameras that produce better quality images, then you must also invest in surveillance-quality hard drives and recorders that can maintain all that data. Again, depending on your purposes and budget, this may be a worthwhile investment.


Understanding camera resolution is very important when planning your security solution. It can be easy to come to the conclusion that higher resolution is always better, but that may not be the case. For most, a camera with a 720p resolution that can record at a stable 15-20 frames per second will get the job done. However, your specific situation may require different surveillance strategies. We here at ENS Security are proud to offer products that fit everyone’s budgets and needs. Get in touch with a sales rep today to learn more about what camera is right for you!

About the Author: Aaron Avila

Aaron J. Avila is a digital designer, social media marketer, and security professional with ENS Security.

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