The basic design of the DSLR dates back to the late 1940s, and it has lasted longer than any other camera design, thanks to its unique combination of extreme flexibility, small-ish size, and durability. SLRs have knocked around inside the canvas bags of war photographers, shot weddings, fashion, portraits, sports, and everything else. And Hasselblad’s medium-format version even went to the moon.  But its era is over; Canon has just announced that it will design no new DSLRs. Its EOS-1D X Mark III will be its last pro model; the future is mirrorless. “Today, mirrorless cameras are taking over in terms of features and sensor quality. This, coupled with their already small, lightweight body and the continuous stream of new lenses made for mirrorless, all these factors are shifting the balance in favor of mirrorless-type cameras,” professional photographer and photography teacher Mario Pérez told Lifewire via email. 

The Reflex

Before the SLR, or Single Lens Reflex, cameras were generally bulky and/or limited. The winning gimmick was the mirror inside the body, which reflected the image from the lens up into the viewfinder. This lets the photographer see the exact frame that will appear on the film or sensor. The mirror flips up (the “reflex” part) out of the way just before you take the photo.  This meant the photographer could use an ultra-telephoto lens and look through it to see that far-off subject up close. Leica’s rangefinder cameras were useless with telephoto or ultra-wide lenses because you always look through a separate, fixed viewfinder.  This meant that an SLR could be used to do any kind of photography. The only reason to pick a different camera is to use a bigger film frame (for better resolution) or a smaller pocket camera.  The SLR made the transition to digital by swapping the film for a sensor, but now mirrorless technology has made that magical reflex mirror obsolete. 

Mirrorless

A mirrorless camera takes a live feed from the camera’s sensor and sends it to the screen in the viewfinder (or on the back of the camera). This means you no longer need a mirror. And because the mirror requires a lot of space, mirrorless cameras are much smaller. This also means smaller lenses, but there are other advantages.  For instance, the DSLR shows the exact frame, but it cannot show the actual finished photo. For that, you have to take your eye away from the optical viewfinder and check the screen. A mirrorless camera shows you the exact image you’ll capture before you capture it. You can preview focus, exposure, even see the image in black and white. Today, sensors and screen tech are fast and high-res enough to compete with the optical view of an SLR, with all those extra benefits. And it appears the market reflects this. Most of us use our phones to take photos. But the pros are switching to smaller, faster, easier-to-use mirrorless cameras. 

Niche Formats

The SLR might be the most flexible camera in history so far, but that doesn’t mean it was the best at everything it did.  “The [Leica-style] rangefinder was a popular alternative long ago, primarily for its compactness,” professional photographer Rafael Larin told Lifewire via email.  In fact, Leica makes the only professional-level film cameras still available today, and those are rangefinders. There are also other niche camera types, but they are usually defined by the size of their sensor rather than being a different kind of camera design. “Medium format cameras continue to be an option for those seeking even greater image quality than a DSLR can produce,” says Larin.  Thanks to physics, large sensors aren’t just about more resolution. They also give a shallower depth-of-field. That is, they can blur the background more than cameras with smaller sensors. But even that’s no barrier to mirrorless—they just need giant sensors.  Unless phone cameras get significantly better and start to offer compatibility with extra lenses or studio lighting rigs, it’s a fairly safe bet that mirrorless cameras will take over the job of SLRs for the foreseeable future.