Do you need to buy a full-frame camera in 2023, or is APS-C good enough? A lot has happened recently, particularly some new, higher-resolution APS-C cameras that appear to close the gap to full-frame cameras and even overhaul some base models.

In terms of APS-C vs full-frame, Amy Davies lets us know the key differences, pros and cons.

The image sensor is the fundamental element of any camera, but with several different sensor sizes available, it can be a bit confusing to know the differences – and to decide which is best for you. Just as bigger negative sizes give better quality with film cameras, the same is true of sensor sizes.

All other things being equal, a full-frame camera will give better quality than an APS-C model. But when you factor in resolution or megapixels, the boundaries become blurred. For example, the Canon EOS R7 (APS-C) has 32.5 megapixels, while the Fujifilm X-H2 and X-T5 (also APS-C) have 40 megapixels, so all three have technically higher resolution than many full frame cameras (typically 24-26MP at this price level).

Key sensor sizes

Probably the two most common sensor sizes you’ll see on the market are full-frame, which is the same sensor size as 35mm film, and the smaller, APS-C format, similar in size to APS-C film. Outside of these two, you also have medium format (larger than full-frame), and Four Thirds (smaller than APS-C), also known as Micro Four Thirds or MFT.

Other than the physical size differences, there are some other differences to take note of between sensor sizes, which we’ll be exploring in this piece. There are benefits and drawbacks to each sensor size, which we’ll also walk you through.

Fujifilm X-H2 sensor

The Fujifilm X-H2 has an APS-C sensor but has somewhat turned conventional sensor size arguments on their head by offering 40MP resolution, which is more than all but a handful of full-frame cameras. Bigger is not always better. Image: Andy Westlake

APS-C vs Full-Frame: What’s the difference?

Full-frame sensors measure the same as 35mm film, which is 36 x 24mm. Meanwhile, smaller APS-C sized sensors measure in at either 23.6 x 15.7mm (Nikon, Pentax, Sony, Fujifilm) or 22.2 x 14.8mm (Canon). That makes full-frame about 2.6x larger in terms of total surface area size.

As already mentioned, there are also Micro Four Thirds (17.3 x 13mm, MFT), and medium format sizes (43.8 x 32.9mm). Technically, there is a larger ‘medium format’ size close to the 645 film size, but that’s only found in very high-end cameras, so we’ll stick to the ‘smaller’ medium format for this comparison.

Full-frame, APS-C, Micro Four Thirds sensor size

Full-frame, APS-C, Micro Four Thirds sensor size

Full-frame sensors can be found in the best full-frame mirrorless cameras, as well as many of the best DSLRs. You’ll even occasionally find a full-frame sensor in a high-end compact camera, such as the Leica Q3. Full-frame sensors are used by Canon, Nikon, Sony, Panasonic, Pentax, Sigma and Leica.

You’ll find an APS-C sensor in many of the best mirrorless cameras too, and they’re also commonly used in DSLRs. APS-C sensors are used by Canon, Nikon, Sony, Fujifilm and Pentax. Again, occasionally there are APS-C sensors found in high-end compacts, like the Ricoh GR III.

The physical size differences lead to both advantages and disadvantages, which we’ll discuss in more detail below.

What is a crop sensor?

You might hear the term crop sensor from time to time, which simply means something that is smaller than full-frame. It’s a term which is most commonly applied to APS-C, but it can also be used to describe even smaller sensors, such as Micro Four Thirds, or even the smaller 1inch sensors that you find in compact cameras and smartphones – though it’s rare to hear those described as such.

The term ‘crop sensor’ comes from the idea that if you put the same lens on both a full frame and an APS-C camera, the smaller sensor in the APS-C camera will effectively ‘crop’ the image area.

What is a crop factor?

Crop sensors have a crop factor that you need to take into account when using lenses with your camera. When using a full-frame camera, whatever focal length is printed on the lens (for example 100mm) is what you’ll get when you shoot with it.

However, when you use a smaller sensor, you’ll need to apply a “crop factor” to get the equivalent focal length. It would make more sense to talk about lenses in terms of their angle of view, but focal length has become so entrenched as an indication of angle of view or magnification, that it’s easier to stay with that.

Nikon, Fujifilm, Sony and Pentax APS-C sensors have a 1.5x crop factor, while Canon APS-C sensors have a 1.6x crop factor. Therefore, the 100mm lens mentioned above gives you an equivalent of either 150mm or 160mm on an APS-C camera – you simply multiply the focal length by the crop factor for the camera sensor.

Other sensor sizes have different crop factors. A Micro Four Thirds sensor has a 2x crop factor (100mm becomes 200mm), while a one-inch sensor has a 2.7x crop factor (100mm becomes 270mm). It also works with bigger than full-frame sensors too – medium format has a 0.79x crop factor, which would make a 100mm lens equivalent to 79mm.

List of sensor crop factors:

  • Medium format = 0.79x
  • Full frame = 1x
  • APS-C (general) = 1.5x
  • APS-C (Canon) = 1.6x
  • Four Thirds: 2x
  • One inch = 2.7x

    Several formats, from smartphones with 1/2.55in sensors and compacts with 1in sensors to medium-format. 

What are the benefits of APS-C?

When it comes to image quality, it’s a general rule of thumb that a bigger sensor equals better performance, with less noise in low light and sometimes better dynamic range – but there are plenty of advantages to APS-C, usually depending on what exactly it is you want from your camera.

One of the big advantages is that APS-C systems are normally smaller and lighter than full-frame equivalents. With often smaller bodies and definitely smaller optics, it’s a good choice if you don’t want to carry heavy gear, such as while travelling or for hiking long distances.

If you want to shoot handheld, it can be easier to keep smaller and lighter bodies stabilised, too, and in-body-stabilisation (IBIS) systems are generally more effective with smaller sensors, which are easier to move quickly to compensate for any camera movement.

Canon EOS R7 with 32MP APS-C sensor - visible here with a green tint

Canon EOS R7 with 32.5MP APS-C sensor.

On that note, the crop factor also means that your longer lenses don’t need to be as long, heavy, or expensive as full-frame equivalents to get you closer to the action. That’s why cameras such as the APS-C format Fujifilm X-H2S and the Canon EOS R7 have been pitched strongly as wildlife and action cameras.

Speed is also something that is generally easier to achieve with smaller sensors, especially at affordable prices. Cameras like the Canon EOS R7 offer up to 30fps shooting, and the Olympus OM-1 can shoot at 120fps, in a camera which costs a fraction of the price of similarly speedy models such as the full-frame Nikon Z9 or the Canon EOS R3. That gives ordinary amateur photographers without the big budgets of professionals the chance to capture fast-moving action in a much more affordable fashion.

APS-C Vs Full-Frame – Does sensor size matter?

Having a smaller sensor can give other benefits as well, and here’s an example which illustrates the cost and weight advantage of using APS-C, particularly when looking at the whole system, which includes the camera and lenses.

  • APS-C system: Fujifilm X-H2S, plus 16-55mm f/2.8 and 100-400mm f/4.5-5.6 costs around $5600 / £5080 and weighs about 2700g.
  • Full-frame system: Nikon Z9, plus 24-70mm f/2.8 and 100-400mm f/4.5-5.6 costs around $10600 / £10200, and weighs about 3600g.

In other words, the APS-C system in this comparison costs half as much and weighs almost 1kg less.

To sum up, the main advantages of APS-C cameras are:

  • Cheaper
  • Faster
  • Smaller
  • Lighter

APS-C cameras are best for:

  • Wildlife photography
  • Sports photography
  • Travel photography
  • Street photography
  • Photographers on a budget

What are the benefits of full-frame?

Full-frame is often seen as the “gold standard” for many photographers, with APS-C often thought of being the preserve of enthusiasts and those with a lower budget. While that’s not strictly fair or accurate these days, there are many advantages of using a camera with a larger sensor.

If the best image quality is your main concern, then generally speaking, full-frame will help you achieve that in a wider variety of settings. Low light performance is generally better, as is the dynamic range for the most part.

Sony Alpha A1 with a 50MP full-frame sensor

Sony Alpha A1 with a 50MP full-frame sensor.

If you crave super high-resolution cameras, you’ll find them with full-frame (and larger sensors). Having said that, the arrival of the 40MP Fujifilm X-T5 and X-H2 has created a lot of overlap, and only a handful of full-frame cameras go higher than this.

Examples include the Sony A1 (50MP), Sony A7R V (61MP) and Sigma fp L (also 61MP). You can go even further with medium format, where you can now get 100 megapixel sensors with the Fujifilm GFX 100S and Hasselblad X2D 100C. This generally makes high-resolution full-frame cameras better suited to high-detail type shots, as well as giving you more flexibility when it comes to cropping in post-production while still maintaining a high pixel count.

It’s easier to achieve a shallow depth of field when using a full-frame sensor. It’s because you use longer focal lengths to achieve the same angles of view, and longer focal lengths produce a shallower depth of field. Although you can achieve the same look when using crop sensors, you might need to get too close to the subject for the same kind of background blur. It’s generally why portrait photographers, for example, prefer to use full-frame.

When it comes to using your lenses, knowing exactly what you’re getting (i.e. 100mm = 100mm) when shooting full-frame is more straightforward. That also means if you’re using older / vintage lenses from DSLR or even film days, you know exactly what you’re getting when using them on mirrorless full-frame models.

To sum up, the main advantages of full-frame cameras are:

  • Better image quality
  • Higher resolution
  • Easier shallow depth of field effects
  • Straightforward to understand lens focal lengths

Full-frame cameras are best for:

  • Landscape photography
  • Portrait photography
  • Low light photography
  • Studio photography

Which should I buy – APS-C Vs Full-Frame?

There’s not necessarily a right or wrong answer when it comes to full-frame vs APS-C and deciding which you should buy. You should think about the types of subjects you like to shoot, the budget you have available, and how much bulk and weight you are prepared to carry around.

Full-frame sensor in the Sony Alpha A7R IV, and the APS-C sensor in the Sony Alpha A6000, Photo: Andy Westlake

Full-frame sensor in the Sony Alpha A7R IV, and the APS-C sensor in the Sony Alpha A6000, Photo: Andy Westlake

If you’re a landscape photographer, for example, looking for a high-resolution camera which can deliver exceptional dynamic range, and you also want to shoot in low light, then full-frame is the obvious choice. Similarly, if you’re a portrait photographer who wants the best resolution and easy-to-achieve shallow depth of field effects, full-frame is the way to go.

On the other hand, if you’re a wildlife or sports photographer and don’t want to splash out on a super-expensive full-frame camera, but you do want to get close to the action, use fast-frame rates and carry something small and lightweight, then APS-C is probably the more sensible option. Travel photographers who don’t want to unnecessarily weigh themselves down might also choose to opt for APS-C, or Micro Four Thirds for an even smaller system.

To conclude, the simple truth is that no, not every photographer needs full-frame. While the larger sensor will provide higher image quality in lots of different scenarios, you’ll also have to pay the price for it both in terms of cost and size and weight. For that reason, many will be served just as well, if not better, by choosing a crop camera.

For more information on this topic read our article: APS-C vs full-frame which sensor size is best?

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For more great guides to cameras, including the best cameras that we think you should be looking at buying, have a look at our latest buying guides, or the latest reviews.

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