In the autumn of 2013, if you walked into any professional photography studio, sporting event, or wedding venue, you’d see a sea of black cameras with red rings and gold badges. Canon’s 5D Mark III and Nikon’s D800 weren’t just cameras, they were symbols of serious photography. Their size, their weight, their distinctive mirror slap, these were the sounds and feels of professional work. The camera industry had a natural order, and everyone knew their place in it. Then Sony dropped a bomb.

On October 16, 2013, Sony announced the a7 and a7R, the world’s first autofocus full frame mirrorless cameras with electronic viewfinders. They were tiny compared to the reigning DSLRs. They looked almost delicate next to a 5D Mark III. And the photography establishment, particularly Canon and Nikon, looked at them and saw a toy.

It would take five years for Canon and Nikon to realize they weren’t watching a cute experiment. They were watching their entire business model become obsolete. By the time they scrambled to respond in 2018, Sony had built a commanding early lead that reshaped the market (one Canon and Nikon are only now beginning to reclaim). This is the story of how two of the most dominant companies in photography slept through a revolution happening right in front of them.

The World Before the a7: Canon and Nikon’s Iron Grip

To understand why the a7 was so revolutionary, you need to understand just how completely Canon and Nikon dominated professional photography in 2013. It wasn’t close. Between them, they controlled roughly three-quarters of the interchangeable-lens camera market, and an even higher share among professionals. Their supremacy was built on decades of lens development, marketing, and ecosystem lock-in.

If you were a working pro, you shot Canon or Nikon. Period. It didn’t matter that Pentax made great cameras or that Sony already had some interesting offerings with their A-mount system inherited from Minolta. Those were fine for enthusiasts, but professionals needed the massive lens catalogs, the support infrastructure, and frankly, the credibility that came with having a 1D X or D4 around your neck.

This dominance wasn’t just about cameras. It was about the complete system: bodies, lenses, flashes, accessories, service centers, and most importantly, network effects. Sports shooters used Canon because Sports Illustrated photographers used Canon. Wedding photographers used Nikon because that’s what their mentors used. The entire industry had calcified around these two giants.

Both companies had experimented with mirrorless technology. Canon had launched the EOS M in 2012, and Nikon followed with the Nikon 1 series. But tellingly, both systems used smaller sensors (APS-C for Canon, and the even tinier 1-inch sensor for Nikon). The message was clear: mirrorless was for consumers, tourists, and hobbyists. Professionals needed real cameras. Big cameras. DSLR cameras.

Sony’s Secret Weapon: Years of Strategic Preparation

Here’s what Canon and Nikon missed: the a7 wasn’t a sudden gamble. It was the culmination of years of strategic moves that flew under their radar.

In 2006, Sony acquired Konica Minolta’s entire camera division, gaining decades of optical expertise and the foundation of what would become their A-mount system. While Canon and Nikon dismissed this as Sony buying their way into a market they didn’t understand, Sony was actually building the foundation for something bigger.

By 2010, Sony was experimenting with SLT (Single-Lens Translucent) cameras like the a77 and later the full frame a99 in 2012. These cameras used a fixed, translucent mirror instead of a flipping mirror, which meant they already had full-time phase-detect autofocus during video and used high-resolution electronic viewfinders. Sony was perfecting the EVF experience and thinking computationally about imaging while Canon and Nikon remained committed to optical viewfinders.

Simultaneously, Sony launched their APS-C mirrorless NEX system in 2010, built around the E-mount (the same mount they’d eventually use for full frame). For three years before the a7, Sony was testing the market, refining the user experience, and building out their mirrorless ecosystem.

The a7 wasn’t from nowhere. It was the calculated fusion of their full frame sensor technology from the A-mount line and their proven mirrorless E-mount system from NEX. And here’s the kicker: Sony wasn’t just a camera maker. They were (and still are) the world’s leading image sensor supplier. Many of Nikon’s best DSLRs used Sony sensors. This vertical integration gave Sony an R&D advantage that Canon and Nikon simply couldn’t match.

October 2013: The Revolution That Nobody Saw Coming

When Sony unveiled the a7 and a7R at a press event in Tokyo, the specs seemed almost impossible. A full frame sensor (the same size as a 5D Mark III or D800) in a body that weighed just 474 grams without a lens. That was less than half the weight of Canon’s flagship. The a7 was so small you could almost hide it in a jacket pocket.

But Sony wasn’t just miniaturizing. They were fundamentally rethinking what a camera could be.

The key innovation was Sony’s existing E-mount with its remarkably short 18 mm flange distance, compared to 44 mm for Canon’s EF mount and 46.5 mm for Nikon’s F mount. This technical detail sounds boring, but it was actually the secret weapon that would crack open the entire industry.

See, Canon and Nikon’s mounts were designed decades before, when cameras needed space for a mirror to flip up and down. That mirror was essential (it let you see through the lens optically). But it also meant the lens had to be mounted far from the sensor, and that distance was locked in forever.

Sony’s mirrorless design eliminated the mirror entirely. With nothing flipping around inside, lenses could sit much closer to the sensor. And here’s where it got interesting: while you can’t mount a short-flange lens on a long-flange camera, you absolutely can mount a long-flange lens on a short-flange camera with a simple adapter.

Suddenly, with adapters like the Metabones, you could mount your entire collection of Canon L-series glass on a Sony body (and the autofocus actually worked, at least to a degree). Nikon lenses could be adapted too, though autofocus performance lagged behind until better adapters arrived. Vintage Leica lenses from the 1950s? Perfect. The Zeiss glass you loved but could never afford a body for? All of it worked.

Sony had done something remarkable: they’d built a professional camera system that didn’t need decades of lens development because it could simply borrow from everyone else’s decades of lens development. Your investment in Canon or Nikon glass wasn’t a reason to stay with those brands anymore (it was a reason to try Sony).

But the adapter story was just the beginning. The a7 was fundamentally a different kind of imaging device. It had an electronic viewfinder that showed you the final exposure before you took the shot. No more chimping (reviewing your LCD after each frame to check if you nailed the exposure). With the EVF, what you saw was what you got.

Sony also brought their deep expertise in video and broadcast imaging (honed through decades of making Handycams, XDCAM cameras, and CineAlta cinema cameras) directly into the a7 line. While Canon and Nikon were still building refined optical instruments with some electronic components, Sony was building a computer that happened to take photographs. The difference would prove decisive.

The Giants’ Miscalculation

In the boardrooms of Canon and Nikon, the a7 wasn’t seen as a threat. It was seen as an oddity, maybe even a validation of their own strategy.

Look, they reasoned, Sony tried to build a “professional” camera and had to make it tiny because they couldn’t compete with real pro bodies. Pros don’t want small cameras. Wedding photographers need the battery life that only a big body provides. Sports shooters need the ergonomics and durability of a weather-sealed DSLR that can take a beating. And nobody (absolutely nobody) was going to abandon their investment in Canon L-glass or Nikkors to buy into an unproven system with limited native lens options.

This dismissal was built on three fundamental assumptions that seemed unshakeable at the time:

First, they believed size was a feature, not a bug. Canon and Nikon had spent decades marketing the idea that a professional camera should be substantial. The grip should fill your hand. The weight should telegraph quality. A camera that looked too small, they believed, made you look like an amateur. Wedding clients wanted to see a “serious” camera. Sports teams wanted to see the lenses they recognized from ESPN broadcasts.

They completely missed that professional photographers didn’t actually love carrying 15 pounds of gear on a six-hour wedding shoot. They didn’t enjoy the back pain from hiking with dual-body setups. They tolerated the weight because they had no choice. Sony had just given them a choice.

Second, they believed their lens ecosystems were unbreakable moats. Both companies had massive lens catalogs built over decades. Canon had over 70 EF lenses. Nikon had over 90 F-mount lenses. Photographers had invested tens of thousands of dollars in glass. The conventional wisdom was that this created overwhelming switching costs (nobody was going to abandon their lens collection to start over).

Third, they were protecting legacy businesses. This was especially true for Canon. They had built a successful Cinema EOS line (expensive video cameras for professional filmmakers). They had deliberately crippled the video capabilities of their DSLRs to avoid cannibalizing those high-margin cinema camera sales. The 5D Mark III could shoot beautiful video, but it had a recording time limit. It overheated. It lacked features that Canon’s engineers could easily have included.

Sony had no such legacy to protect. They could put their best video tech into the a7 without worrying about killing another product line. So they did. And when hybrid shooting (photographers who also shot video) became the norm rather than the exception, Sony was ready. Canon was still protecting their cinema line.

The evidence of how badly Canon and Nikon misjudged the moment? Look at what they were actually doing during this period. Canon continued developing the EOS M system with its APS-C sensor while simultaneously planning a separate, incompatible full frame RF mount for the future. This split focus divided their R&D resources. Nikon pushed the Nikon 1 with its 1-inch sensor. Both were positioning mirrorless as consumer-grade technology, something for people who didn’t need a “real” camera.

They saw the market Sony was actually pursuing (professional full frame mirrorless) and decided it didn’t exist. Classic Innovator’s Dilemma.

The Five-Year Desert: 2013 to 2018

For five years, Sony had the entire full frame mirrorless market to themselves. Not because the market was small, but because Canon and Nikon had decided not to compete in it.

And Sony didn’t waste that time. They iterated relentlessly.

In 2014, they released the a7 II, following Olympus’s pioneering work on IBIS by bringing 5-axis in-body stabilization to full frame for the first time (a feature that made every lens you owned, adapted or native, effectively stabilized). In 2015, they launched the a7R II with a groundbreaking 42-megapixel sensor and improved autofocus. In 2017, the a7R III kept the 42 MP resolution but added dual card slots, much better battery life, faster AF, and improved handling.

Sony’s early lens lineup wasn’t perfect (many of their initial E-mount lenses were criticized for being soft, slow, and expensive). But in 2016, they launched the G Master series, starting with the 85mm f/1.4 GM, and the quality gap closed dramatically. Third-party manufacturers like Sigma, Tamron, and Zeiss, seeing where the market was heading, committed to the E-mount with their own lineups of high-quality glass.

Meanwhile, Canon and Nikon weren’t standing still. In 2017, Nikon released the D850, widely considered the greatest DSLR ever made. It was a masterpiece of engineering that won countless “camera of the year” awards (even over Sony’s mirrorless offerings). The D850’s massive success likely reinforced Nikon’s complacency. It convinced them that the DSLR still had a long life ahead and that pros would stick with the “best” optical-based system. They were perfecting mirrors and pentaprisms while Sony was eliminating them entirely.

But the most important release came in February 2018: the Sony a7 III. If the original a7 was the proof of concept, the a7 III was the refinement that would become the default choice for a generation of photographers.

The a7 III was spectacular. It had 693 phase-detection autofocus points covering 93% of the frame. It had Eye-AF that could track a subject’s eye even when they turned their head. It delivered 10 fps burst shooting with continuous AF tracking. It had dual SD card slots for backup and overflow. It shot oversampled 4K from the full width of the sensor at 24p (1.2× crop at 30p). And at launch, it cost just $2,000 body-only (undercutting the Canon 5D Mark IV [released in 2016] by nearly $1,500).

For working professionals, especially those doing hybrid photo and video work, the a7 III was a revelation. You could shoot a wedding ceremony at 10 fps with Eye-AF, ensuring every frame was tack sharp, then immediately switch to 4K video for the reception. The image quality was stunning, and the body simply disappeared during use.

Sony wasn’t just selling cameras anymore. They were selling a complete, mature system that could handle any professional assignment.

The Panic: Canon and Nikon’s 2018 Response

In September 2018, Canon and Nikon finally responded. Canon announced the EOS R system. Nikon announced the Z6 and Z7. Both were full frame mirrorless cameras designed to compete directly with Sony.

On paper, they looked competitive. The EOS R had a 30-megapixel sensor and Canon’s excellent color science. The Z7 had 45.7 megapixels and Nikon’s legendary build quality. Both companies made a big deal about their new mounts (the RF and Z mounts, respectively), which would enable better optical performance than even their legendary DSLR lenses.

But when reviewers and professionals actually got their hands on these cameras, the gaps became obvious. These weren’t competitors to the a7 III, Sony’s third-generation camera. They were competitors to the original a7 from 2013. Canon and Nikon had spent five years watching Sony iterate, and they’d responded by essentially building what Sony had built half a decade earlier.

The EOS R launched with only a single SD card slot. For wedding photographers, event shooters, and anyone who couldn’t risk losing files to a corrupted card, this was a dealbreaker. The a7 III had two. The EOS R’s autofocus, while good, couldn’t match Sony’s 693-point system or sophisticated Eye-AF. And most damningly, the EOS R’s 4K video had a severe 1.7x crop factor, turning your wide angle lenses into normal lenses and making the camera nearly unusable for serious video work.

Nikon’s Z6 and Z7 were better in some ways (the Z7 in particular had a gorgeous sensor), but they too launched with single card slots and an autofocus system that felt a generation behind Sony’s. More importantly, both Canon and Nikon launched their new systems with tiny lens lineups. The EOS R launched with just four native RF lenses. The Z system launched with three.

Yes, both companies offered adapters for their legacy DSLR lenses. But this was Sony’s strategy from 2013, except Canon and Nikon were doing it five years later without the benefit of having spent that time building out native mirrorless glass. 

The market spoke clearly. The a7 III became one of the best-selling cameras of all time. Working professionals who had been waiting to see what Canon and Nikon would do bought Sony cameras instead. YouTube was suddenly filled with videos of Canon and Nikon shooters making the switch.

The Aftermath: A Three-Way War

To their credit, Canon and Nikon learned quickly. By 2020, Canon released the excellent R5 and R6, which fixed most of the EOS R’s problems and added impressive features like 8K video and dual card slots. Nikon released the Z6 II and Z7 II with dual card slots, then later the spectacular Z8 and Z9, which proved they could build world-class mirrorless bodies that competed directly with Sony’s flagship a1.

Today, the mirrorless market is engaged in a brutal three-way war. Canon’s R5 Mark II, Nikon’s Z9, and Sony’s a1 are all phenomenal cameras that can compete on nearly every metric. Canon has been exceptionally aggressive, and recent market data shows they’ve caught up to (and in some regions surpassed) Sony in new full frame mirrorless sales.

But here’s what Canon and Nikon can’t get back: those five formative years from 2013 to 2018. Sony used that time to build an ecosystem that’s still the most comprehensive in full frame mirrorless. They have one of the most extensive native lens lineups. They have the strongest third-party support from manufacturers like Sigma and Tamron. Most importantly, they won an entire generation of photographers who entered the professional market during those years and built their businesses on E-mount.

Rental houses like LensRentals report that Sony mirrorless gear remains among their most-rented cameras. In fact, in 2024, Sony tied with Canon on the company’s top 20 most rented list, with each company occupying four spaces with their camera bodies. YouTube creators and Instagram photographers (the new generation of image-makers) still overwhelmingly choose Sony for their first professional system. That’s the power of getting there first.

Canon and Nikon aren’t going away. They’re too big, too well established, and frankly, their recent cameras are too good for them to fail. But they lost something irreplaceable: they lost five years. Five years where third-party lens manufacturers built their strategies around E-mount. Five years where the industry narrative shifted from “Sony is trying to compete” to “Canon and Nikon are trying to catch up.”

The Lesson: You Can’t Sleep Through a Revolution

The Sony a7 story isn’t just about cameras. It’s a masterclass in disruption and the dangers of incumbent thinking.

Sony understood something that Canon and Nikon didn’t: the camera market was undergoing a fundamental transformation. It wasn’t just about moving from mirrors to mirrorless. It was about moving from optical instruments to computational photography. From single-purpose cameras to hybrid tools. From systems built on legacy technology to platforms designed for the future.

Canon and Nikon were building better horse-drawn carriages. Sony was building automobiles.

The tragedy for Canon and Nikon is that they had every advantage. They had the brand recognition, the dealer networks, the marketing budgets, and the decades of optical expertise. If they had taken Sony seriously in 2013 and responded in 2014 or 2015, this story might have ended very differently. Sony is a massive company with plenty of profit from other divisions, and it’s entirely possible they would have exited the camera and lens market entirely.

Instead, Canon and Nikon waited. They protected their legacy businesses. They assumed their customers would stay loyal. And they woke up in 2018 to find that the market had shifted beneath their feet.

Today, if you walk into a professional photography studio, you’ll still see plenty of Canon and Nikon gear. But you’ll also see a lot of Sony cameras with those distinctive orange GM lens rings. The sea of black and red and gold has been joined by black and orange. And while Canon and Nikon have built excellent cameras that can compete technically, they’re still fighting to reclaim the cultural and ecosystem momentum that Sony captured during those five critical years.

That’s the cost of sleeping through a revolution. Not necessarily losing the war, but spending a decade fighting to win back ground you should never have lost in the first place.