Photography 101: Camera Sensor Size Formats Explained

Sensor size is one of the most important factors when deciding between cameras. Sensor size affects image quality, depth of field and low-light performance. Larger sensors generally — but not always — provide higher quality images, with better dynamic range and more control over creating out-of-focus backgrounds (or bokeh). In this article, we'll cover the four most common sensor sizes found in digital cameras, and share some sample photography to demonstrate the difference.

A related photography term to sensor size is crop factor. While the focal length of a lens remains constant regardless of the sensor size, the crop factor determines how—and how much of—the scene is captured. Learn more about this in our article about focal length.

In order of largest to smallest, this article covers:

• Medium format

• Full frame

• APS-C

• Micro Four Thirds

Medium format

Medium-format sensors are the largest sensors commonly found in digital cameras. These sensors provide exceptional dynamic range and detail, making medium-format cameras an excellent choice for landscape and studio photography. Medium-format cameras tend to be much slower and larger in size, so they're not usually a great fit for sports or wildlife photography. They also tend to be rather expensive, and their compatible lenses are too. So, if you're a beginner, you might want to start with a camera with a smaller sensor. For many landscape and studio photographers, medium-format cameras are the very best. To see medium-format cameras in action, see how the Pentax 645Z vs Fujifilm GFX 50S compare for landscape photography.

In terms of size, medium-format cameras have — until fairly recently — been pretty large. Since 2016, when Hasselblad released the Hasselblad X1D-50c, medium-format mirrorless cameras have entered the mainstream. Their slimmed-down size has helped reduce the physical burden on photographers, opening them up to more creative avenues.

Medium-format sensors tend to also offer greater resolution and more megapixels. For example, the Fujifilm GFX 100S II (pictured above) and Hasselblad X2D 100c both offer 100 megapixels. Read our Fujifilm GFX 100 II review.

Full frame

Full frame is usually seen as the 'standard' sensor format, particularly for professional photographers. Originally based on the size 35mm film, full-frame sensors are smaller than medium format but still provide excellent image quality, offer strong low-light performance and output images with high resolution—pixels galore. Most full-frame cameras will give you good control over depth of field, so they're a great choice for portrait photography in particular.

While full-frame cameras have traditionally been bulkier than APS-C and Micro Four Thirds cameras, the rise of mirrorless technology has meant full-frame cameras are now slimmer than ever. The Sony A7CR, for example (pictured above) is known for being really compact. However, they tend to be more expensive. Full-frame DSLRs, which had been the reserve of professional photographers for a long time, have now come down in price. If you're keen to shoot on a full-frame sensor but don't quite have the budget for a mirrorless setup, then a full-frame DSLR — like the Nikon D810 — is an excellent choice.

Almost all the main camera brands produce full-frame cameras, including Canon, Nikon, Sony, Panasonic and Leica. The notable exceptions are Fujifilm and Olympus/OM System.

APS-C

APS-C sensors are smaller than full frame, but still provide good image quality. The smaller sensor size generally means you get a more compact and portable camera setup. They tend to be more affordable too. So, they're the usual starting point for beginners, and popular among hobbyist photographers — and some professionals, too. The lower weight and price of APS-C cameras come at a cost, though. They tend to give you less control over your depth of field and offer worse low-light performance, although technological developments are helping to improve these.

Cameras with APS-C sensors include the mirrorless Nikon Z50 (pictured above) and the Canon EOS 60D DSLR. Most of the camera brands manufacture APS-C cameras: Canon, Nikon, Fujifilm and Sony. Some of the most popular compact cameras, like those by Fujifilm — check out our Fujifilm X100-series guide — use APS-C sensors.

Micro Four Thirds

Micro Four Thirds sensors, created in 2008 in partnership between Panasonic and Olympus, are a third of the size of a full-frame sensor. Micro Four Thirds cameras are usually lighter and more portable than APS-C and full-frame cameras, but they tend to be poor in low-light conditions and aren't great at controlling depth of field. However, they're still a good choice for travel photographers and vloggers, for example. Some filmmakers use the Micro Four Thirds cameras, like the Panasonic DC-GH5 II above, as secondary cameras on video shoots.

The great thing about Micro Four Thirds cameras is that all the gear is cross-compatible. You can use most Micro Four Thirds camera gear from Panasonic and Olympus/OM System interchangeably—so you don't have to switch everything out if you jump between brands. Other well-respected Micro Four Thirds cameras include the OM System OM-1 and the Olympus OM-D E-M5 Mark III, which you can learn more about in our E-M5 Mark III review.

Other sensor formats

Some cameras have even smaller sensors than Micro Four Thirds. These include one-inch, found in the Sony ZV-1 compact camera and DJI Mavic 2 Pro drone.

Read more tips and techniques on the MPB content hub.