When you’re shopping for a camera, sensor size is one of the most important specs to understand — yet it’s also one of the most confusing. Terms like “full frame”, “APS-C”, and “Micro Four Thirds” get thrown around constantly, but what do they actually mean, and does it matter which one you choose?
Here’s our plain-English guide to camera sensor sizes.
What is a camera sensor?
The sensor is the digital equivalent of film. It’s the component inside your camera that captures light and converts it into an image. The size of that sensor has a significant impact on image quality, low-light performance, depth of field, and the lenses you can use.
The main sensor formats
Full Frame (35mm)
A full frame sensor measures 36mm x 24mm — the same dimensions as a frame of 35mm film. This is the largest sensor format found in mainstream interchangeable-lens cameras, and it’s the benchmark against which all other formats are measured.
Advantages:
- Superior image quality, especially in low light
- Greater dynamic range and tonal depth
- Shallower depth of field for subject isolation
- Wider field of view with any given lens
- More detail in large prints
Best for: Professional photographers, wedding and portrait photographers, landscape photographers, and anyone who regularly shoots in low light or needs the highest possible image quality.
Browse full frame mirrorless cameras — including the Sony Alpha A7 series and Nikon Z full frame range.
APS-C (Crop Sensor)
APS-C sensors are smaller than full frame, typically measuring around 23.5mm x 15.6mm (or 22.2mm x 14.8mm for Canon’s variant). Because the sensor is smaller, it captures a narrower field of view than a full frame sensor using the same lens — this is known as the crop factor, which is typically 1.5x for most brands and 1.6x for Canon.
Advantages:
- Smaller, lighter camera bodies and lenses
- More affordable than full frame
- The crop factor effectively extends the reach of telephoto lenses — great for wildlife and sports
- Excellent image quality for most uses
Best for: Enthusiast photographers, travellers, wildlife and sports shooters, and anyone stepping up from a smartphone or compact camera who wants great image quality without the full frame price tag.
Browse APS-C DSLR cameras or explore APS-C mirrorless options.
Micro Four Thirds (MFT)
Micro Four Thirds sensors measure approximately 17.3mm x 13mm — roughly half the area of a full frame sensor. The format is used by OM System (formerly Olympus) and Panasonic Lumix, and has a 2x crop factor. Lenses designed for MFT cameras are labelled with focal lengths that already account for this, so a 25mm MFT lens delivers a 50mm equivalent field of view.
Advantages:
- Very compact and lightweight systems
- Excellent lens range with consistent quality
- Strong video capabilities, particularly in Panasonic bodies
- More affordable entry point
Best for: Travel photographers, videographers, and anyone who prioritises portability without sacrificing interchangeable lens flexibility.
Does sensor size affect image quality?
Yes — but context matters. A larger sensor captures more light, which generally means better performance in low-light conditions, less digital noise at high ISO settings, and greater dynamic range. However, modern APS-C and MFT cameras have closed the gap significantly, and for most everyday shooting conditions, the differences are less dramatic than they once were.
The biggest practical differences show up when:
- Shooting in low light without flash
- Printing images at very large sizes
- Trying to achieve very shallow depth of field
- Shooting at very high ISO settings
Which sensor size is right for you?
There’s no single right answer — it depends on how you shoot, what you shoot, and how much you want to carry. As a general guide:
- Full frame — if image quality is your top priority and budget isn’t a major constraint
- APS-C — if you want excellent quality in a more affordable, versatile package
- Micro Four Thirds — if portability and a compact system are your priority
For a deeper dive into how sensor size affects your lenses, read our guide to understanding digital camera crop factor.
Get expert advice at Ted’s Cameras
Still not sure which sensor format is right for you? Our team across Ted’s Cameras stores nationwide can help you find the right camera for your needs and budget. Browse our full camera range online or visit your nearest store today.