Buying a camera often comes down to one number: megapixels. Manufacturers put it on the box, reviewers lead with it, and buyers use it to justify the upgrade. But most working photographers will tell you it’s one of the least important specs for the vast majority of shooting situations. Here’s what megapixels actually do, when they matter, and when paying more for them is a waste.
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Megapixels video tutorial
In just 90 seconds, we unravel the mystery behind megapixels to help you determine whether or not you need more of them.
What are megapixels? A brief definition
Megapixels (MP), which translates to “one million pixels,” dictate how much detail your camera’s sensor can capture. In digital photography, the number of megapixels in an image refers to the total number of pixels that make up the image. To determine this number, multiply the number of pixels in the width of the image by the number of pixels in the height of the image.
The higher the megapixel number, the more potential detail can be captured within an image.
How do megapixels affect image quality?
Generally speaking, the more megapixels an image has, the higher its resolution and level of detail. This is because a higher number of pixels means that the camera is capable of capturing more information.
However, simply having more megapixels doesn’t necessarily mean that the image will be higher quality. Other factors like lens quality, sensor size, color resolution, dynamic range, and more play a role in determining image quality.
Additionally, the level of detail that can be captured by a high-megapixel camera may not be noticeable unless the image is viewed at a large size. For example, the image below was shot with a 12 megapixel Nikon D700 and the image quality is excellent. You can really see the detail when viewing the image online, as a slideshow, or in 10-20″ prints. For these viewing conditions, the 12MP sensor provides more than enough resolution and allows for a small amount of cropping.
When does size matter?
While it’s true that other factors beyond megapixels can compensate for lower megapixel counts, there are situations in which high megapixel counts are necessary. For example, when sent to print, a 20MP file can yield an 18″ wide print without any upscaling in Photoshop or other photo editing software. Yet, how often do you print 12″x18″ photographs? For most consumers, the answer is “not often.”
And for very large prints, the math is more forgiving than most people expect. Viewing distance matters as much as DPI — a 24-megapixel file can produce a billboard-sized print with no visible quality loss at normal viewing distance, because billboards are viewed from tens of feet away, not arm’s length. The print size panic most photographers feel is largely unfounded.
For a deeper look at megapixels and print size, this video breaks it down clearly:
How many megapixels do you need for online display?
Most images end up online, usually on social media. However, online and social media usage rarely exceeds 2MP. That means the other 18MP you paid for never really get seen. Even a 4K display can only present 8MP worth of your photograph.
How megapixels affect cropping
When an image is straightened or cropped in post production, resolution is lost. So, if you crop your images heavily, a higher megapixel count will give you more flexibility.
This also applies if you display an image photographed in landscape orientation in a vertical (or portrait orientation) format. For example, to place a landscape-oriented photo in a vertical slideshow format, such as an Instagram reel, a higher megapixel count will work better.
Who needs more megapixels?
Do we all need $50k cameras that produce 100MP images? Not exactly. Most cameras feature 20-40MP these days, and yet most photographers don’t use their camera to its full potential. A camera with a 20MP sensor will only yield 20MP worth of detail when it’s used by a proficient photographer — meaning the photographer must understand how to maximize detail and resolution using lighting and other means.
Highly proficient photographers seeking cameras that can print directly to large format with incredible detail reproduction, or that provide extreme cropping capabilities, can take advantage of cameras with 30, 50, or even 100MP.
For everyone else, purchasing a 50MP camera is like buying a 600-horsepower car to drive 30 mph. The megapixel war is largely a marketing one between manufacturers, and it has little to do with what most photographers actually need.
When do megapixels matter?
Sheer resolution becomes a factor when enlarging and performing extreme crops. Because detail is more visible when blowing a photo up to a 20×30 inch canvas versus a 4×6 inch print, having a higher megapixel resolution is important in bringing out more crisp details in your enlargements. Also, if you have a 40-megapixel image and need to crop 80% of it, you’ll still have plenty of detail left for that enlargement.
The image above was shot with the 36-megapixel Nikon D800. With this much resolution, there’s plenty of room to crop the image and still produce high-quality photos. The example below is a 100% crop sample from the previous image — there’s still enough detail for posting on the web or even printing.
Similarly, if you’re an advertising or fashion photographer, ultra-high-resolution sensors can mean a lot more flexibility in production. Imagine an editorial photographer taking a single full-length portrait and then creating printable crops focusing on the subject’s facial expression, dress, wrist, neck jewelry, and shoes — all from one shot.
Compared to the Nikon D800, the Phase One medium format camera has more than twice the megapixels, resulting in an incredible amount of detail even after extreme crops.
The image above was taken with an 80-megapixel digital back sensor. Even at just 50% crop, we can still get beautiful details of the model’s face, clothes, and jewelry with enough resolution for a full-page spread publication.
The wild card: re-sizing a high-res image
One more megapixel myth worth addressing: many people argue that downsizing your high-res images isn’t as good as simply having a sensor with lower megapixels in the first place. Comparing image detail and dynamic range, this doesn’t hold up.
If you compare images from the 16MP Nikon D4 and the 36MP D800 — with the D800 image re-sized down to 16MP — you’ll see far more detail in the re-sized D800 file. By re-sizing a high-res image, you do gain a considerable amount of low-light performance, or at least better noise reduction performance.
Can too many megapixels actually be bad?
If you shoot a high volume of images, like for a wedding or action sports, you may not want 4,000 images at 40 megapixels per shoot. A studio that shoots 150 weddings per year may produce over a million RAW images annually. At 40-50+ megabytes per image, that’s 25-30 terabytes of storage. Of course, the average shooter may only need one or two extra memory cards and hard drives — but storage needs scale fast.
Editing speed is the other consideration. A wedding photographer generating 3,000-5,000 images per wedding will feel even a few extra seconds per image compound across their workload. Double or triple the megapixel count, and editing time can increase by quite a few hours per week.
The bottom line on megapixels
Megapixels are one useful indicator of what a sensor can do, but they represent only one of many factors that determine image quality. Lens quality, sensor size, and shooting technique all play a significant role. Whether megapixels matter comes down to how you use your images — and for most photographers shooting for web, social, or standard print sizes, the camera they already have is more than enough.
