Why Aren’t Mirrorless Cameras Smaller?

An advertisement for Canon EOS R System mirrorless cameras.Cannon

The mirrorless camera was originally touted as the smaller, lighter, and more convenient alternative to the DSLR. However, if you watch the last mirrorless cameras from Canon, Nikon and (to a lesser extent) Sony, that didn’t really matter. Let’s see why.

Canon’s new flagship mirrorless camera, the EOS R5, weighs just under 26 ounces and measures 5.43 x 3.84 x 3.46 inches. The closest digital SLR to the company, the 5D Mark IV, weighs 31.4 ounces and measures 5.94 x 4.57 x 2.99 inches. While there is certainly a difference, and the R5 is lighter and smaller (in most dimensions), it’s not exactly night and day. Then of course you have to add a goal as well.

The Canon EOS R5 with a long lens attached.The Canon EOS R5 is not a small camera after adding a lens. Cannon

If you put a RF 24-105mm f / 4 L IS USM lens (24.5 ounces) on the R5, and a EF 24-105mm f / 4 L IS II lens (28.1 ounces) on the 5D, their total weight increases to 50.4 and 59.5 ounces, respectively. You will feel the difference if you hold them both simultaneously. However, neither a particularly light configuration – in fact, they are quite similar.

But here’s the real kicker: The RF 24-105 and EF 24-105 are lenses of similar size and performance. One of the biggest advantages of mirrorless cameras do they use brand new lens mounts, so manufacturers can make even better lenses.

The mirrorless replacement of the incredibly popular EF 24-70 f / 2.8 L II USM lens (28.4 ounces) is the RF 28-70 f / 2.0L USM, which weighs 50.4 ounces quite ridiculous. Put that on an R5, and the total weight is 4.75 pounds compared to the 3.74 pounds of the 5D and its 24-70mm lens. Now the mirrorless camera rig weighs more!

How did we get there?

Canon and Nikon manufacturing decisions

The main reason mirrorless cameras aren’t smaller or lighter is simple: Canon and Nikon didn’t want them to be. We’ll explain why a little later, but first, a brief history lesson.

Canon’s and Nikon’s digital SLR platforms are, in technological terms, old. Canon introduced the EF mount in 1987, while the first Nikon F mount lenses were released in 1959. This is mostly prehistoric times.

A Canon EOS 620.This 30 year old EOS 620 still works with all new Canon lenses. Harry guinness

Although Canon and Nikon have made good use of their lens platforms, they have now reached severe physical limits with the extent to which they can push them further. Canon probably would have loved to release that RF 28-70 f / 2 monster that we mentioned above for their DSLRs.

However, due to the design of the lens mount, the company was unable to manufacture an equivalent lens. Canon has been limited to a 24-70mm f / 2.8 for decades.

When it was time to design a new lens mount for their flagship mirrorless cameras, Canon and Nikon just didn’t choose to get smaller – they just got bigger. By removing the mirror, they were able to reduce the distance between the lens and the sensor, which improves the image quality. The enlargement of the frame made it possible to achieve lenses with wider apertures.

They now have more options to innovate, which means bigger and crazier lenses.

In theory, Canon and Nikon (and, before them, Sony) could have designed smaller lens mounts, but that would have constrained them more.

This brings us to the next reason why mirrorless cameras are still so great.

Lens size

While cameras get a lot of attention, it’s the lenses that do most of the work in photography. The laws of physics are a major problem for manufacturers looking to make things smaller.

A full-frame camera sensor is standardized from a piece of 35mm film. They are 36 x 24mm and that can’t really be changed. Sure, there are smaller image sensors out there, like the ones used in smartphones and APS-C cameras, but they come with a whole host of tradeoffs.

The high-end amateur and professional photography industries are built around the 35mm standard, including lenses.

The relation between the focal length of a lens and sensor size affects the appearance of things. On a full frame camera, wide angle lenses have focal lengths less than about 40mm, while telephoto lenses have a focal length greater than approximately 70mm. In the middle are the normal glasses, which offer a perspective similar to that of the human eye.

The focal length, however, is a physical property of a lens. A lens with a focal length of 100mm does not need to be strictly 100mm long, but it will be in this stage.

A photographer using a huge telephoto lens.Getting rid of a small mirror wouldn’t make this setup much lighter. Ryan Fletcher / Shutterstock

As long as camera manufacturers are committed to making a full frame camera, they are also committed to the lenses being a certain size (quite heavy). Small savings can be made by using lighter materials or more compact designs. However, it is impossible for a 24-70mm zoom lens to be much smaller than it is now and to be good.

Because the lenses have to be a certain size, so do the cameras. That’s why Canon’s lightest full-frame mirrorless camera, the RP, still weighs 17.1 ounces, about 2/3 the weight of the flagship R5.

Even cheaper and lighter cameras still have to work with the same lenses.

The decline of the consumer camera market

So far, we have focused on the high end of the camera market, as this is the part that offers the most hope for manufacturers.

Since 2010, global digital camera sales have fallen 87%, from 121.5 million to 15.2 million. Smartphones have stolen the low-end consumer-driven camera industry.

Since almost everyone who wants a small, light, and easy-to-carry camera already has one in their pocket, there’s little incentive for manufacturers to develop a competing product.

Mirrors have never been so big

Part of the discussion about the size and weight of the camera that gets lost a bit is that DSLR mirrors have never been this big to begin with. They take up a bit of space (which is why mirrorless cameras have slightly smaller dimensions), but they’ve never been particularly heavy. The sensor, electronics, battery, LCD screen, viewfinder, SD card slot, lens mount, etc., are still there.

Also, as we saw earlier, with the little size and weight saved, manufacturers have used more advanced lens mounts. This is the same reason why removing headphone jacks from phones did not lead to smaller, lighter phones, but rather more advanced phones.

Are there small mirrorless cameras?

If you really want a small, lightweight, mirrorless camera, you’re in luck! They exist, they just aren’t flagship products for most brands. Indeed, the compromises necessary to achieve them do not lend themselves to good technical data sheets.

Canon, for example, has the EOS M range of APS-C mirrorless cameras. Sony Alpha Series also includes many APS-C models. Unfortunately, since these use the same lens mount as full frame cameras, most lenses are still quite large.

however, Leica M range mirrorless rangefinders are about as compact as a full frame camera can be.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.