As you begin to research cameras, you’ll likely hear some technical jargon about sensors. While it’s easy to ignore some elements of any devices, there’s no way to work around sensors. But what is a sensor and what does it do? In this guide, we’re diving into the often confusing world of imaging sensors. By time we’re done, you’ll have a better understanding of the most significant component in our digital camera.
About Sensors
What Is an Imaging Sensor?
At the heart of our digital cameras sits an imaging sensor, which serves as the digital equivalent of film in a camera. It is a light sensitive chip that captures photons through a grid of photo sensitive nodes called photodiodes and then converts those photons into digital data. In other words, it captures the light that is focused by our lens and converts said light into a digital image which is then stored on our memory card.
These come in a variety of sizes in order to accommodate different camera sizes and of course, price point. This poses the important question, does sensor size matter? After all, it’s commonly stated that larger sensors are overall better than smaller ones. Is there any validity to these claims? Could it possibly be true? The simple answer is yes.
Sensor size is one of the most important factors in determining your camera’s overall performance and image quality. A larger sensor will capture more light than a smaller one and will have an effect on things like depth of field and low-light performance (all things we just so happen to have guides on).
But hold on! Just because a larger sensor has greater overall image quality, doesn’t mean smaller sensors are inherently bad. Quite the contrary. In fact, you’d likely have a hard time finding a difference between images taken with various sensor sizes unless you look closely, and we mean really closely. While size may be a significant factor for some photographers, there’s more to sensors than size alone.
Resolution vs. Sensor Size
Now to preemptively clarify a common mix-up. Resolution and sensor size are two very different aspects of our camera. Resolution is a measure of detail our image contains and refers to the number of pixels in our imaging sensor. If a camera has a 24-megapixel sensor, this means our sensor has 24 million pixels. That same number of pixels can be packed into any sensor size, and as a result, the size of the individual pixels changes as the size of the sensor changes.
Bigger pixels can absorb light better but limit the maximum resolution of our camera. Higher resolution cameras with 45 megapixels and up have similar sized pixels to smaller imaging sensors! Our sensor size refers to the physical dimensions of our sensor. As seen in the graphic above, not all sensors are created equally. Some are larger and others smaller. From a technical There are a multitude of reasons for these variations, and each determines things like the size of the camera itself.
Sensor Sizes
Why we pick one over the other will ultimately come down to our intended use. With the basics covered, let’s take a detailed look at the sensors themselves. We’re going to look at the various sensors found primarily in DSLR, Mirrorless, and Point and shoot cameras. They’ll be listed from smallest to largest. There are other sensors out there, but many are not as commonly used or they’re found primarily cinema cameras and camcorders.
1/3.2” Sensors (4.5x3.5mm) – One of the smallest imaging sensors commercially available. These are typically found in smartphones which enhance images through AI learning and post processing. For most folks today, these are the most convenient cameras available and perfectly suited for everyday photography.
1/2.3” Sensors (6x4.5mm) – These are the most common sensors found in entry-level to mid-tier compact cameras, also known as “point-and-shoot” cameras. They’re slightly larger than those found on the average smartphone, but they come paired with an optical zoom, which puts them a step ahead of their more convenient cousins. If you want to take photos without the distractions that come with smartphones, this is the way to go.
1” Sensor (12.8x9.6mm) – As cameras become more advanced, they come equipped with even larger sensors. The 1” sensor is typically found in higher end point and shoots like the popular Canon G7X and Sony RX100 series cameras. This adds to their allure as the quality of the images they produce begins to noticeably outperform even the best smartphone cameras. In a similar vein is the new Half Frame 1” (13.3 x 8.8mm) sensor. Technically still a 1” sensor, but oriented in a vertical format, this unique to the Fujifilm X half as of late 2025.
Micro Four Thirds (MFT) (17x13mm) – Micro four thirds had its first big wave in the late 2010s as a smaller alternative to the bulky DSLR cameras. These were some of the earliest mirrorless cameras and they held a solid spot in the industry for many years thanks to their incredibly compact size. With the sensor so small, lenses could be made smaller as well, leading to one of the most portable interchangeable lens formats available. Fun fact, a micro four thirds sensor has an aspect ratio of 4:3.
CMOS 1.4” Sensor (16x13mm) – Similar to MFT in overall size, this a newcomer to the industry was first found in the Canon PowerShot V1 camera. As mentioned above, this sensor is about the same size as the MFT sensor, but in a 2/3 aspect ratio, making for slightly wider images more akin to the standard 4x6 frame size found in most cameras.
APS-C (Canon) (23x15mm) – APS-C or “crop” sensors are slightly smaller than full-frame and are among the first digital imaging sensors created. They also are the second most common sensor size available being the go-to option for entry level and prosumer level DSLR and mirrorless cameras.
APS-C (24x16mm) – Why two APS-C sizes? Well, Canon’s is proprietary and slightly smaller than the competition. Nikon, Sony, Fujifilm, and Ricoh use this slightly larger sensor with a 1.5x crop factor. The difference between the two is negligible, but worth noting. The added crop factor paired with newly designed, lightweight super-telephoto zooms make this a popular choice for bird watchers photographing distant subjects or sports photographers looking to up the quality of their images.
Full-Frame (36x24mm) – 35mm film was the standard for photographers The most common sensor type just so happens to be nearly identical in size to the traditional 35mm film negative. Full frame sensors have been known as the best of both worlds. They’re compact enough for everyday use, but large enough to capture stunning detail and clean image quality. Photographers looking for more detail, cleaner images in lowlight and better overall
Medium Format (44x33mm Crop 645) – The largest available sensor is known as a medium format or “crop 645” sensor. While not as large as a true 645 negative, it’s a similar form factor and aspect ratio, so close enough. These cameras are ideal for landscape and studio shooters, though with cameras getting smaller and smaller, medium format is becoming more popular for weddings and even street photography. A select few specialty cameras from brands like Fujifilm and Hasselblad feature these sensors.
Other Points to Consider
Crop Factor
There are certainly good reasons why you may choose one sensor size over another. At surface level, small sensors make for smaller cameras. Street photographers and traveling photographers may prefer these cameras for their superior portability. Alternatively, a studio or landscape photographer who wants as much detail as possible will likely prefer a larger sensor. Larger sensors do technically produce “better” images, but this assumes you’ll be producing large prints, publishing, or at least “pixel peeping”.
Another area where sensor size can affect our decision is crop factor. Smaller sensors have the added benefit of seeing less of what our lens sees. While this may sound like a detriment, it can actually be beneficial as it means we effectively increase the reach of our long lenses by proactively cropping our image.
Crop factor can also make lenses appear wider as sensors get larger. While APS-C sensors have a crop factor like 1.5x or 1.6x, large medium format sensors have a crop factor of 0.79x. Let’s look at a 50mm lens for example. Full frame shows a 50mm lens as designed, but if we mount the same lens on a Canon crop sensor camera, we multiply 50 by 1.6 to get an effective focal length of 80mm. Now if we take that same lens and put it on a medium format sensor, we get a 39.5mm effective focal length.
Aspect Ratio
One last point to be aware of is aspect ratio. Sensors come in different shapes or aspect ratios, which is the proportional relationship between a video or image’s height and width. It is expressed as two numbers divided by a colon such as 1:1 or 2:3. As you may guess, 1:1 is a square, while 2:3 is the typical portrait format captured by most cameras. While this won’t affect the quality of our images, it will determine how we compose our images.
So, does sensor size matter? Yes, but not for any one reason. Bigger may be better for some, but not others. You may even benefit from a smaller imaging sensor. If you’re looking to take some photos to post on social media or put in an album after a vacation, stick to a smaller sensor. If you’re noticing things like how blurry a background is or you want to print your images larger, then consider a camera with a larger sensor. It all depends on your exact usage.
As you begin your photography journey, check out our other educational guides and articles on the B&H Explora page!
