Full frame mirrorless EOS 5DM in the works?


With much speculation, including from myself, about Canon working on a new full-frame mirrorless EOS camera the rumour mill has been in overdrive. So, let me add to that with my own.

When Canon launched their first mirrorless camera in 2012 (shown above) the world looked on and, in general, got bored and went away again. There was nothing especially wrong with the EOS M (except the dreadful autofocus speed until it was fixed in a later firmware update) but neither was it groundbreaking in any way except one – the ability to use EF lenses with a suitable adaptor. In fact, that’s probably the reason that most photographers chose it over the better options from Sony, etc.

Canon then launched the EOS M2 which was so underwhelming they weren’t even brave enough to launch it worldwide – it was never officially sold in Europe or America.

Then came the EOS M3, a much better camera, but by no means flawless. I really like the EOS M3, but it’s still no Sony A6000.

Finally, Canon have just launched the EOS M10, which by all accounts (I haven’t seen one yet), is a revamped EOS M2 with built in flash (and not hotshoe!) and better autofocus aimed at the budget market and, in particular (apparently), female photographers.  Yet again it has nothing that makes you feel any sense of awe in what Canon is achieving in mirrorless.

Canon’s mirrorless strategy seems to remind me of the classic Monty Python sketch from ‘The Holy Grail’


Despite the lack of success, Canon keep trying. And the reason is simple. Mirrorless is the future. It may not be as reliable as a mirror based system at the moment in terms of autofocus speed, but we all know that is improving year on year, and good mirrorless cameras such as the Sony A7R II outperform the autofocus speed on many popular DSLR cameras. Technically it seems inevitable that the archaic technology of a physically moving mirror which has always limited the speed of SLR cameras needs to be bypassed. One of these days when I have a little more time I’ll talk about an early technical solution from Canon for this very problem, the EOS RT camera. But not now. I’ll leave that fun for later!

So. the latest rumour to come out of the CanonWatch website is that the mirrorless full-frame camera from Canon has been delayed due to ‘mount-related issues’. Which essentially means they can’t quite get it working right.

But what about a mirrorless full-frame camera that takes standard EF lenses? It isn’t such a crazy idea for two reasons:

a) Leica have just launched the monstrously sized Leica SL mirrorless camera which is almost the same size and weight as a Canon 5DSr. So the worry Canon might have of releasing a larger mirrorless camera because “no other idiot has tried it yet” has now gone.



b) Canon have already launched several EOS mirrorless cameras with a standard EF interface. This isn’t new to them. Of course I’m talking about their EOS Cinema cameras, such as the brand new EOS C300 II. So this is not an entirely new path for them.



So. Perhaps an EOS 5DM mirrorless camera is in the works? By removing the mirror assembly you have room to fit a superior electronic viewfinder. But wait, there’s more!  What could you possibly do with all that space in front of the sensor where the mirror used to be? Well, some of the EOS Cinema cameras have a neat trick, they have Neutral Density filters that can pop up here to automatically restrict light to the sensor (perfect when taking long exposures on a bright day or for many artistic shots) – certainly that would be a benefit especially for videographers using a new 5DM camera. But maybe it’s possible to have different filters altogether. It might be an engineering challenge but there’s no reason why an internal circular polarizing filter couldn’t be built that could flip up and be enabled/disabled on will.  An even greater engineering challenge would be having a flippable anti-aliasing filter as in general this needs to be perfectly aligned with the sensor. I’m not going to say it’s impossible but I can’t see how it can be done. And I think in general the digital camera world is moving away from anti-aliasing filters – the real answer is to not have such regularly repeating patterns of RGB photosites which generates the aliasing problem, but to have either totally irregular pattern of photosites or a larger than 2×2 pattern, such as the 6×6 repeating pattern in the Fuji X-Pro 1 camera. But these alternatives are (I believe) heavily protected with patents, even though they seem blindingly obvious to anyone trying to come up with a solution to moire on digital images.

Another minor benefit of ditching the mirror is full support for EF-S lenses. Of course with their smaller image circle you’d need to have a crop option – but that’s already present on the 5DS/5DSr so that’s not an issue.

There is another possibility. Turn the entire camera into a tilt-shift system. We’ve already seen that Canon have a patent for a tilt-shift adaptor for an EOS-M type camera but such an adaptor couldn’t be used on existing DSLRs with EF lenses for reasons that I explained in the article linked above. But there’s no reason why the entire front of the camera couldn’t be designed to tilt and shift, under electronic control. The advantages of this are phenomenal. Firstly, you get tilt-shift with every single EF lens ever made (although in practice only a select number of lenses would have an adequate image circle to be able to work reliably at full frame. But the patent document does talk about automatically cropping the frame down to compensate for the image circle – although that might be kind of odd to see your image effectively zoom in as you shift in order to deal with the different image circle. But tilting the mount seems so clunky and mechanically awkward. How on earth would you weather seal that? Better still would be to tilt and shift the sensor itself. maybe that means an mirrorless camera would be even deeper than a normal DSLR, but I think the benefits would be well worth while. Additionally, with the tripod mount fixed relative to the lens rather than the sensor it makes it trivial to produce automatic tiled panorama images of several times the megapixel resolution of the sensor itself. Want to create 100 megapixel panoramas from a 40 megapixel 5DM? No problem, set it up on your tripod, press one button and wait.

Perhaps Canon are being very smart – I would expect that such a system could be covered in many ways by the patent listed above without actually giving away their true intentions.

Of course the elephant in the room with mirrorless is battery life. I’ve gone for trips before with two or three fully-charged batteries for my EOS 5D Mark III and never had a problem with battery running out. But with the EOS M3 even with three fully charged batteries it’s a constant worry about whether I’ll make it through to the end of the day with my two spare batteries (I would buy more, but LP-E17 batteries are expensive and no third-party replacements are yet available.) So any professional EOS 5DM would need some serious battery options – probably the easiest would be to add two batteries to the pack. And please… bring back a dual battery charger such as the one that came with the EOS D30.


Finally… 2017 will be the 30th anniversary of the EOS system, and Canon haven’t yet done a ‘retro’ style camera. Perhaps it’s time to pull out my favourite looking EOS camera from the past, the EOS 50, and style it somewhat after that. Now that would make it perfect!



Exciting times…


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2 Responses

  1. Mike Fougere says:

    Does the M3 with adaptor crop the EF lense view circle?

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