Full-frame gets its name – and much of its level of manufacturer backing – from the fact that it allowed photographers to use their film-era lenses as originally designed. The economics of sensor manufacture pushed the likes of Canon, Nikon and Konica Minolta into the use of smaller sensors at the start of the digital era, but the large user-bases, including professional users with existing lens commitments, along with significant R&D investment having been spent on building up lens lineups, created powerful incentives to move to sensors that captured the “full frame” that those film-era lenses were designed to project.

That same push from users wanting to keep using their existing lenses, along with an audience now familiar with the image quality of digital full-frame, ensured that similar pressures came to bear as the industry moved across to mirrorless, such that the dimensions of “35mm” film still dominate the pro and enthusiast-focused products from Canon, Nikon and Sony.

And this concentration of development efforts means “full-frame” is the most extensively supported format on the market. Canon, Nikon and Sony all make APS-C cameras, but the bulk of their lens investment has been focused on full-frame, just reinforcing that format’s primacy in their lineups.

Richard Butler / Mitchell Clark

But that doesn’t mean it’s the best format or even some kind of carefully considered optimum. Like all formats, it’s an arbitrary choice; in this instance, it dimensions came about because a German engineer decided to use silent-era cinema film the wrong way round, more than a century ago.

Every sensor format represents a trade-off between size, price and image quality. Larger sensors (or film formats) have an inherent image quality advantage because they have more light-capturing surface, but the lenses needed to provide any given field-of-view have longer focal lengths, making them bigger, heavier and more expensive. You can hunt around for exceptions: a particularly large or small body, or one especially small prime lens, but for the system as a whole, the overall trade-off remains true.

Full-frame digital can offer spectacular image quality, but even with the move to mirrorless, its cameras and lenses are larger than their film-era counterparts were. If the 35mm film format was a Goldilocks balance of quality vs portability and cost, then digital full-frame isn’t, because it offers a completely different balance. Better image quality, but with both a size and financial cost (and these differences are worth considering before you decide to point out that 35mm film could be called ‘small format’).

If you’re after something closer to the balance of size, price and image quality that 35mm film offered, you might find it in APS-C instead. Its smaller sensor means it doesn’t match the depth-of-field that 35mm film offered, but in terms of IQ, camera and lens size, it’s much closer to being a match. Just compare the size of the Nikon FE, Fujifilm’s X-T5 and Nikon’s Zf, paired with appropriate lenses, to confirm this for yourself.

Richard Butler

Likewise, for travel and wildlife in particular, the smaller Four Thirds format lets you further downsize the whole setup, giving lenses with longer reach or compact prime-lens combinations that let you travel light. Yes, you pay an image quality cost for moving to a smaller format, but you might end up with a shot that you simply wouldn’t get if your kit becomes too unwieldy to carry with you. 

The same is true in the other direction: 44 x 33mm Medium Format offers around a two-thirds-of-a-stop advantage over full-frame, at the same exposure, if you want better image quality. But those same downsides of larger, more expensive lenses are inescapable.

All formats are arbitrary size/price/image quality trade-offs. They may be popular or well-supported, but none is inherently best, because each has an innate compromise at its heart. And what makes sense for you, isn’t necessarily ideal for everyone.

Those other options, and that ability to choose a format that suits your kind of shooting, will only exist if those formats continue to be supported by manufacturers and by photographers. We lose that choice if we decide that some formats are lesser, or just stepping stones to another, rather than treating each as an entity in its own right.