What are camera sensor sizes and why do they matter?
Cameras have changed significantly since they were created in the 19th century. From a simple box with a hole in it to digital set-ups costing more than five figures, there is a huge variety of quality and artistry available to photographers today. Behind all the bells and whistles a camera is basically two things- a way to collect light and way to store the information from that light.
The way to collect light is, of course, through your lens. Your lens captures and controls the light that enters your camera as you create an image. The way to store the information from that light in the sensor.
Before digital cameras were invented, film was king. The size of the film determined the amount of information your camera could hold in one image. 35mm was and still is the standard (we’ll come back to that) but there were other sizes too- medium format cameras, large format cameras, and lots of other spinoffs that have come and gone throughout the decades.
What does this mean now for digital cameras?
The cameras sensor takes the place of the film. The size of your camera sensor is one of the main determining factors of the quality of your image: the bigger the sensor size, the higher quality potential for the image.
Currently, there are five main sensor sizes for digital cameras:
Micro 4/3 (pronounced “four thirds”)
Mobile phone (there is some variation here)
Let’s explore each of them:
A full frame sensor is the same size as one frame of 35mm film. The higher end, professional models of most cameras have full frame sensors. For example, the Canon 5D series, Nikon D800 series, and Sony mirrorless A7 series are all full frame cameras. These have the biggest sensors (besides medium format film cameras, although those are much rarer and very expensive) and usually come at the highest price point. If you are a newer photographer, I wouldn’t recommend splurging for one of these cameras unless you have plenty of extra dough! They are great, but you can also get wonderful images with other cameras as well.
APS-C (Crop Sensor)
The APS-C sensor size is also based off of a film size- the Advanced Photo System film in the ‘classic’ setting. This film was discontinued in 2011, but it has left it’s mark on the wildly popular APS-C sensor size. This sensor is also sometimes called a “crop sensor.” Most of your mid-range cameras are going to have APS-C sized sensors- much of the Canon and Nikon lines, the entire Sony A6000 line, and all Fuji mirrorless cameras. APS-C sensors can absolutely capture wonderful images. Compared to full frame, you will see a bigger decrease in quality when taking photos in low light (especially without a tripod).
Pronounced “micro four thirds”, this sensor size is most popular with Olympus and Panasonic camera models (which makes sense, as Olympus created it!). It is probably not good for a serious photographer, but is absolutely fine for starting out! You can take great photos if you have good lighting and know how to use the other elements of your camera (ISO, aperture, shutter speed).
A one inch sensor is pretty small and not very common. It is more likely to be seen on point and shoots or extremely compact cameras.
Mobile phone sensor sizes
These are very small compared to actual cameras. Although you can still great great photos with some phones, it would be difficult to enlarge them if you ever wanted a bigger print. However, in our instant-world, sometimes a phone is all you need to share an image online.
These two photos above were taken from the same place with the same settings, but the first image was taken with a full frame camera at 40mm, and the other was taken with a cropped frame camera at 40mm. The other settings, ISO 800, f4, and 1/40sec are all the same.
A note about lenses
All lens sizes are based off of a full frame sensor. For example, if you have a 50mm lens, it will act as a 50mm lens on a full frame camera. For a cropped sensor, or APS-C, it will appear more zoomed in. As a result, your 50mm lens turns into the equivalent of a 75mm lens on a camera with a cropped sensor. This is what’s called a crop factor of 1.5.
Most lenses are made specifically for their camera sensor size, but there are some lenses that fit both APS-C and Full Frame. If you are buying a new lens, be sure to do your research to determine if it fits your camera. Also note, the measurement in millimeters will always be aligned with a full frame camera, even if they are made only for cropped sensors. For example, a 24mm lens for and APS-C camera system will be called 24mm, but will act as a 36mm lens.
Sensor size is very important to image quality. If you are serious about photography, I would seek out a camera that has an APS-C or Full Frame sensor size. However, remember that size isn’t everything (see what I did there?) Having a good lens, knowing how to compose an engaging image, and knowing how to use your camera settings are all crucial steps to creating photographs you can be proud of.
About the author
Rose Trafford is a travel photographer and writer with a passion for finding the positives in people and places. She has traveled to over 40 countries and gotten herself into all sorts of strange situations, such as locked in a Korean ATM and questioned in a Chinese police station. She frequently travels using points and miles, saving an average of $9,000 a year. She has appeared in Money Magazine and the Iowa State Fair Photography Salon (which is more legit than it sounds). When she’s not traveling she enjoys taking photos of anything and everything- lately with a 35mm or instant camera in her hand. You can find her at @thecompass.rose, www.thecompassrose.co or www.roseconstance.com.