Mirrorless Cameras vs SLR Cameras Underwater: Alex Mustard Breaks Down the Real Differences

Why Mirrorless Has Taken Over the Underwater Camera Market

These days it’s said that ‘when two or three are gathered together in the name of underwater photography, that the mirrorless debate will be among them’! Everyone accepts that mirrorless cameras are the immediate future for underwater photography, but the debate rages about when to jump. Many have already. Others maintain that their current SLR is all the camera they need and they are better off investing in diving than gear. Both views are correct.

If we’re diving into this debate, there are three truths on the subject we must start with. First, the camera manufacturers have decided that the future is mirrorless, and this is where we will see all the new capabilities and specifications. This decision, it must be said, was of course made in their interest, not ours. Second, that SLR cameras didn’t suddenly become poor cameras just because mirrorless cameras arrived. Don’t believe the marketing hype. They are still excellent underwater cameras! And finally, the outcome of this debate is only going in one direction. Of the last four overall winners of UPY, three of them were full frame mirrorless shots, while one was full frame SLR. And on my own workshops I’m increasingly seeing full frame mirrorless being the most-popular system on any week.

The mirrorless revolution definitely caught the photography industry a little by surprise. As little as ten years ago almost no serious shooters were using Sony cameras, the market was dominated by the big two of Nikon and Canon. But Sony invested heavily in mirrorless, releasing impressive cameras that changed everything. Within five years Sony accounted for about 50% of serious camera sales and Nikon and Canon were scrambling to catch up. Canon brought the first real contender in the R5, which recovered market share and satisfied topsiders. Quite a lot of underwater Canonistas took the leap too, but while this camera was the real deal on land, it didn’t deliver universally underwater. I know several photographers who bought housings and then after a trip or two went back to their SLRs for underwater work. Other friends who were Canon shooters switched to Sony and more recently to Nikon when their impressive Z8 was released (helping restore Nikon’s market share). The main criticism of the original R5 was its electronic viewfinder that struggled with the high contrast underwater scenes that we typically compose, falling a long way short of the view offered by the optical viewfinder of an SLR. If you had to sum it up, it was fine for macro, but frustrating for wide angle.

Sony, Nikon and Canon: How the Big Three Compare Underwater

Then towards the end of last year the Canon R5 Mark 2 hit the shops and housings swiftly followed. Was Canon fully back in the underwater game able to stand shoulder to shoulder with the top guns: Sony’s A7RV and Nikon’s Z8? I have been very fortunate to be able to use all three over my last three visits to the Cayman Islands.

I shot the reefs first using the Sony A7RV, then the Nikon Z8 and in January, the Canon R5 Mk 2, providing a unique opportunity to evaluate the three cameras for underwater shooting. And my conclusion, they are all far more similar than they are different.

Jump on a photography forum and you will be welcomed into the world of measurebators – who are far more interested in specs than pix. They love nothing more than fanboying (they are always men) over their favoured product and concluding everything else is from the stone-age. You’ll read their posts about these three cameras, where the differences are put under the microscope. Yes, all three of these cameras have slightly different strengths and weaknesses, but for real world underwater shooting they all offer very comparable performance. And importantly, all three of them offer a superior and more enjoyable shooting experience to any SLR. Something that could not be claimed about their direct ancestors.

The Canon R5 MkII: Is Canon Back in the Game?

The Canon’s superpower is autofocus. All mirrorless cameras of this generation have seriously moved autofocus on from the era of SLRs, but the new Canon R5 Mk2 takes it on the furthest. It is fast and smart, able to work out what it should be focusing on, grabbing it and keeping in tenaciously in focus. That said you do need to get on its wavelength to get the most out of it, I missed as much as hit on my first macro dive with the camera, which left me shocked.

But after a few days of adapting to how the intelligent autofocus thinks, it was clear to me it was the most potent of them all with typically tricky macro subjects.

The other big underwater improvement over the first generation R5 is the electronic viewfinder, which is bigger, brighter and truer to life than the original. And importantly it also handles those high dynamic range scenes in a more similar way to SLRs. The R5 also really impressed me with its image quality at high ISO, and with its battery life, the best I had experienced in a mirrorless camera that isn’t way bigger than your old (with a mirror) camera.

The Bottom Line: It’s a Great Time to Be an Underwater Photographer

The take-home message is that Canon is back in business underwater. By that I mean that Canon loyalists no longer need to think that the grass is greener elsewhere.

The R5 Mk2 absolutely holds is own against the top underwater options from Nikon and Canon. I wouldn’t put any of them substantially ahead of each other, but all three are more capable and more enjoyable to shoot than any SLR.

It maybe all change in the camera world, but there is no debate that it is a good time to be an underwater photographer.

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