Teardown of the Canon EOS R Mirrorless Camera

I’ve wanted to look inside the new Canon and Nikon mirrorless cameras since the moment they were announced, so I’m probably more excited about this than you guys are. I’m really not sure what to expect. Early on, when we took apart a Sony A7R, we were struck by how clean and straightforward mirrorless cameras were compared to DSLRs. Later, we took apart an A7RIII and found that increased capabilities led to increased complexity, although still not as complex inside as a DSLR.

So we expected things not to be too complicated – no mirror box, optical prisms, off-sensor AF system, etc. We hope Canon cameras to have clean, even elegant, engineering; like the 5D IV teardown shows. We haven’t done a Nikon SLR teardown in quite a while (the D7000 was the last one), but their camera engineering is pretty similar to Canon’s, although being Nikon they still like to leave some soldered-wire connections here and there. So we figured that the new Canon and Nikon mirrorless full-frame cameras would be more straightforward than their SLR cameras, and perhaps Nikon set down the soldering gun and slowly stepped away.

But really we had no idea how things would look inside, if we might see some cool new engineering, what the weather resistance would be like, etc. So we took apart both a  Canon EOS-R and a Nikon Z7 just to have a look around. (The Z will get written up as soon as I can get to it.)

The EOS-R, 2018


The Outside

Since this is a brand new camera to us, we started by removing all the grip rubber so we could see where most of the screws were. It’s worth noting that Canon seems to have new grip adhesive tape; it was both easier to remove and retained its stickiness for replacement better than what we’ve seen before. Important news for the none of you that intend to repair your cameras at home, but we like it., 2018


Now the camera looks kind of like your dog shaved down for summer. I kind of like it, though. If I get one, I may just take the grips off. The shell, BTW, seems to be a polycarbonate with a slightly rough surface. It would grip nicely., 2018


The rubber around the viewfinder is actually screwed into place. Good news for those of you who, like me, sometimes find yourself wondering when the viewfinder rubber came off. Bad news for those of you who like to take it off on purpose for some reason or other., 2018, 2018


Next, we went to the side to remove the I/O port covers. This is held on by four screws; removing those lets it slide right off., 2018, 2018


With the cover off we see a very nice flex along the I/O ports. Why ‘nice’ you ask? Because that means that some or all of the I/O ports are not soldered to the main PCB. We have to replace a lot of main PCBs because someone jerked a cable, pulling an I/O port off of the board., 2018


Next, we remove all the visible screws around the body., 2018


And the diopter adjustment from the viewfinder., 2018


There is a nice thick weather seal under the diopter adjustment knob. For those who want to skip ahead, the knobs and dials are all weather sealed nicely, but not much else. As long as it only rains on your knobs and dials, though, you should be fine., 2018


Opening the Case

With all the screws out, the back assembly can be removed, LCD and all, after the flexes between it and the main PCB are detached., 2018


At a glance, this looks much like a Canon SLR: the back assembly containing the LCD and controls, the main PCB with neatly laid out flexes., 2018


Looking closer, there are some apparent differences. First among these is that the shutter motor and electronics are at the bottom of the camera, underneath the shutter box. In a Canon DSLR, it’s generally to one side., 2018


Here’s a close up of the shutter motor for those into such things., 2018


I should also show there’s weather sealing below each of the top dials. As you can see to the right of that, though, the rest of the body depends on a plastic overlap to keep stuff out, there are no gaskets., 2018


The Back and LCD Assembly

The back panel looks like the rear panel from any camera with a hinged LCD. There’s shielding over the controls (left in the picture below) and connections are going out to the LCD., 2018


One thing that caught our attention immediately was the LCD attachment. You can see it seems only held down by two screws and a metal clamp. This could be great (LCD change is a common repair) unless it’s weak (making LCD replacement a more common repair)., 2018


The bracket looks pretty robust, though, and the screws holding it down are the largest in the camera by far., 2018


The bottom line is it makes LCD replacement something takes minutes, not hours., 2018


And the bracing and weather sealing around the bracket are excellent and sturdy., 2018


While we were back here, we removed the shielding to look at the weather sealing around the buttons. Again, thick and excellent., 2018


Other Subassemblies

We’d already unfastened all the screws and disconnected flexes, so we slid out the I/O subassembly., 2018


I was a little disappointed, but not surprised, that it contained only the RCA-type plugs. Better than nothing, of course, but the HDMI plug is the one that rips off the board most frequently, at least in our experience., 2018


Similarly, the EVF had already been disconnected so it could slide right out., 2018


Finally, the top assembly was removed (there were two more screws internally holding this on)., 2018


The top assembly has a lot of electronics and connections: EVF, various selectors and switches, the top LCD, and the touch bar. From a repair standpoint the top assembly is a single part; if anything in there breaks, you replace the whole thing. It can be disassembled but it’s very time consuming, and there’s no reason to. I will note, because the photo is small, that there is no weather-sealing foam along the edges. Plastic-to-plastic contact is all the weather sealing there is., 2018


Main Body

With all the subassemblies removed, Aaron just had to remove the half dozen screws to take off the main PCB., 2018


You can see a small electrical shield on the surface of the board in the image above; there’s more significant shielding underneath., 2018


With the shields removed we can see the PCB is not particularly dense., 2018


The inner side shows the SD card slot soldered to the board. Repair guys hate this since a broken card slot means replacing the entire board, but SD card slots are certainly more reliable than CF slots. Soldering the SD assembly to the board is the way it’s usually done., 2018


With the PCB removed, all that’s left to see is the image sensor’s board (green), the shutter mechanism below it, and the battery box (black). Like all mirrorless cameras, the EOS-R is simpler than an SLR., 2018

If you look carefully at the aluminum frame over the image sensor, you’ll notice 3 Torx (star) screw heads, two along the left side, one in the upper right. These are the sensor adjustment screws. During assembly, the image sensor is adjusted so that it is perfectly (in theory) aligned with the lens mount.

Each of these screws is spring-loaded. They are loosened and tightened during the adjustment process to align the sensor and lens mount to be within a few microns of parallel. We don’t have the automated equipment to do this adjustment (we can do it, but it involves hours of trial and error) so we aren’t going to do any further disassembly of the sensor plate., 2018


The last piece to take off is the bottom plate., 2018


While there was no weather sealing around the edges of the plate, but there is some at the tripod mount., 2018


The tripod mounting plate comes off next, and there’s an important detail here. The tripod screw inserts into a pressed out cup (red arrow)., 2018


We like long cups because a long tripod plate screw (and they vary in length) can pop the top of a short cup out, leaving a free-floating piece of metal inside your camera. Free-floating metal inside your camera is a bad thing. A very bad thing. This one is nice and long and I can’t imagine a problem occurring., 2018


Here is the socket in the camera that the tripod cup sits in. The aluminum plate that you see crossing the hole is the sensor frame. You can see this would be a bad place to have a piece of metal floating around in. Not to mention a bad place to have a hole open to the environment., 2018


Before we start putting things back together, we’ll show you a front view of the stripped down camera. I’ll mention that I like that auto-close shutter feature a lot., 2018


It was rather a boring disassembly, really, about what we should expect for Canon doing a Canon 6D Mark II quality mirrorless camera. It’s neatly laid out and nicely engineered inside. One thing that struck me is that it’s not very crowded inside there, or as we like to say ‘they left a lot of air inside’.

This view that I haven’t shown you yet, kind of illustrates that; there’s a pretty big gap between the circuit boards and the image sensor. If you look back at the Sony A7R III teardown (or the Nikon Z teardown to come) you’ll notice there’s not that much space inside; it’s taken up by the IBIS system which is big and thick., 2018

Do I think future Rs are going to have IBIS? No, I don’t. Canon has been very clear that they think lens stabilization is superior. The space is probably just a matter of ergonomics and perhaps heat diffusion. But there’s certainly room for it.

Speaking of the Sony A7RIII, it’s taken a bit of internet trashing for its lack of weather sealing. Throw no stones from your glass house, oh Canon shooters. The Canon EOS-R is just about the same; well-sealed buttons and dials, not much else. That means, I think, that it will be fine in a misty rain for a while, but don’t get it saturated and don’t set it somewhere wet.

You can make an argument that tightly fitted plastic shells are good weather sealing. Then again, you can argue that weather sealing means waterproof. Lots of people do that on the way to finding out the warranty doesn’t cover water damage.

The Canon EOS-R sells currently for $2299. It’s very close in build quality and weather sealing to the Canon 6D II which sells for about $1600. So for $600 you get the R mount, cool new slider bar thingie, a bit better (we assume) processing and four more megapixels. That actually sounds fairly reasonable to me.

Reason also suggests Canon is working the kinks out with a (fairly) reasonably priced camera before they come out with a mirrorless pro-level camera. But being reasonable never got anybody anywhere on the internet. The internet is filled with people pretending they’re moving from one brand to another as they justify the choices they’ve already made. So I will, in internet fashion, do some click-bait brand comparison.

The Sony A7r III can be had for a bit under $3,000, has equal build quality, a better native lens selection, more megapixels, etc. My opinion is it’s a better camera (not necessarily system) for the money. It should be; we’re comparing the first generation to a fourth generation.

The Nikon Z6 (comparable to the Canon EOS-R) is $2150 while the Nikon Z7 (comparable to the Sony A7RIII, at least in megapixels) runs a touch over $3,500. I’ll make more build quality comparison’s when I’ve taken a Z apart.

So, which would I buy, right now? None of the above; I don’t know enough yet, and I try very hard to avoid Generation 1 technology. If you forced me into a corner and said: “if you made your living with a camera, what would you shoot today?” I’d say either a Sony with a lot of adapted lenses or an SLR.

That’s today, and that’s my logical answer. Tomorrow (tomorrow being a couple of years) I will absolutely be shooting a mirrorless camera, but I have no idea yet which one. Of course, those of you who know me very well know I won’t be able to stand it, and I’ll ignore my own advice and get one of these in a month or two; and almost certainly decide it was the wrong one a month or two after that.



Roger Cicala and Aaron Closz

October, 2018

Author: Roger Cicala

I’m Roger and I am the founder of Hailed as one of the optic nerds here, I enjoy shooting collimated light through 30X microscope objectives in my spare time. When I do take real pictures I like using something different: a Medium format, or Pentax K1, or a Sony RX1R.

Posted in Equipment
  • Michael Clark

    Yeah, because we all know an aluminum soda can is so much more robust than a thermos made out of engineered plastics, right?

  • Michael Clark

    Only if you consider engineered plastics that possibly outperform metal alloys in terms of strength (tensile, compressive, and torsional rigidity), thermal contraction, etc. to be lower build quality.

  • Zerphannes

    On the pictures with the SD card slots, I think I see a small battery, does anyone know what it is for and how to change it?

  • Adam Fo

    Look at the underside of the top cover, It’s the same ivory color ? If the covers and main frame are plastic the camera is way off the build quality compared to what was found in the Z7 tear down and presumably Z6…

  • Michael Clark

    Hmmm. Maybe the info at that link is for the next ‘R’ body that some folks think will be a higher end model? Or maybe they changed their mind after that brocure was in the works? Much of the language in it suggest it is a fairly rough translation from something that was originally produced in Japanese.

  • Adam Fo

    I’m a bit bemused you say the main body is polycarbonate ? Canon specifically say in their technical analysis quote:

    “With the EOS R we decided to use magnesium alloy not only for the exterior, but also for the body. Magnesium
    alloy excels at heat dissipation, and it is an ideal material for a heat sink. The heat generated by the imaging
    processor etc. is distributed efficiently within the camera through this body…”

    The photo shown shows a large magnesium casting

    (one way to tell metal from GRP and other composites is the tongue test. Metal, apart from titanium, always feels colder at room temperature)

  • Of course I know the A9 is a capable camera. Sadly it’s the only one – the X-T3 has taken some reasonable steps in the right direction as well to reduce rolling shutter on both video and stills taken with electronic shutter.

    We’re not there yet though – on most of these expensive recent mirrorless cameras the video is cripple by design and the electronic shutter stills as well.

  • Have you not read about Sony A9? That thing can shoot sports without rolling shutter issues. The development is going in that direction.

  • Martin K.

    Roger, could I kindly ask you to make a similar disassembly and analysis of the Leica SL?

  • Pat Farrell

    Nice teardown. You wrote: “I was a little disappointed, but not surprised, that it contained only the RCA-type plugs. ” Do you really mean RCA plugs, which were used in WW2 radios and were therefore cheap for use in Hi Fi and later Stereo. RCA have a ground sheild and a single conductor. Hard to tell from the photos, but they probably are really “phone plugs” like the now obsolete 1/8″ stereo headphone jack that stereos, iPods and smartphones had. Its easy and cheap to find “phone” plugs in 3 and 4 wire configuration.

  • Thomas

    But you have to align the sensor, not the cover glass. I doubt they are (or even should be) aligned. The sensor is not smooth.
    Then again, just imaging the sensor surface through that beam splitter could give an accurate distance measurement – just check if the bayer pattern is in focus.

  • Fully electronic shutter usually gets you banding under artificial light. With motion, fully electronic shutter gets you rolling shutter. Electronic shutter is not fit for purpose for live performance in any way, shape or form.

  • K-1 while being an excellent example, also has the issue that the viewfinder doesn’t get stabilized. Albeit it’s a very small issue.

    “Additionally if you wanted to, you could put an EVF into an SLR for use in lockup mode” Yeah, I’d love that. If there was a true hybrid DSLR that could switch on an EVF when in Live-view, I might consider it.

  • “The majority of camera buyers will use the kit lens”

    I didn’t say that the majority DOES buy it, I said that the majority probably WANTS it. But they can’t get it since most beginner cameras don’t have it.

    “Most primes are wide angle…”

    What about popular lenses like 35/50/85 1.8/1.4?

    “..that IBIS on a FF camera is not nearly as effective as IBIS on cropped cameras..”

    And for some reason people extend this argument to say that IBIS on full frame cameras is not useful at all, like “Full frame IBIS is not as good as m4/3, therefore it’s not a problem that EOS R completely lacks IBIS”. That’s a very false argument.

  • Still not as quiet as completely electronic shutter.

    “Anybody shooting live performance should get a lifetime ban for using burst mode during a performance”

    And this is precisely what you can do with a mirrorless cameras without worrying about getting banned.

    I did some documentary photo jobs a few years ago, which included many sensitive situations where silence was preferred, and I constantly had to think about when I could shoot just due to the shutter noise. I wouldn’t have had that issue today.

  • “But the majority do not seem to care that much about IBIS otherwise sales of IBIS cameras would be far higher relative to non-IBIS cameras.”

    It’s not that simple, because many users are locked to their system due to lens investment. It’s not like just switching your phone every now and then. If people were to start from zero, and given a choice between IBIS and no IBIS, all other things equal, pretty sure that most would choose it.

    Saying that the majority doesn’t want IBIS because most people don’t buy it is a false argument, because not everyone can buy it. Most beginner cameras don’t have it, most DSLRs don’t, etc. People don’t skip IBIS by choice specifically, but they accept being without it for those reasons. Anyways you get my point, it’s not false to assume that most would want it.

    “But the religious revolutionary tone by mirrorless fans is…grating. Dare to mention that you prefer OVF or longer battery life and you get crucified because how could you question IBIS or AF calibration? It’s beyond annoying”

    You’re not reading what I say correctly. I don’t have any issues with people saying that >they< don't like mirrorless. My issue is with people saying things like "mirrorless doesn't make sense" as if it was a fundamental fact and not an opinion. There is a big difference between those two statements. For some users, those features ARE revolutionary. For me and many others, seeing exposure in the viewfinder, and also not having to worry about micro adjust focus far outweigh the bad battery life and other things.

  • Many mirrorless cameras have viewfinders that perform well enough in dark conditions that stopped down metering isn’t a problem. Except in night photography where it’s a problem.

    Also, if you don’t feel like mirrorless makes sense for stills, that’s fine and all. But don’t try to make it seem like a universal truth that they mostly make sense for video. Many photographers have switched to mirrorless specifically for those advantages, without having any interest in video. Me included, seeing the exposure in the viewfinder before the image is taken, and not needing focus micro adjustment for the lenses were my two biggest reasons. And for many of us, those advantages far outweigh disadvantages in battery life. It’s flat out wrong to say that “those features aren’t revolutionary” – for many users they actually are.

  • Daniel Taylor

    I do have experience with modern EyeAF and I do not consider it “revolutionary.” I can see it being useful for casual shooters, particularly parents for whom photography is a means to an end (memories of children) and not a hobby or profession.

    BTW, those who claim it is revolutionary based on their on personal experience are ALSO offering anecdotes.

    I quoted Northrup’s test because it was a legitimate effort by a respected reviewer to ascertain how EyeAF performs on two modern FF mirrorless bodies. Somehow a published test is still “anecdotal” though because it doesn’t reinforce the “mirrorless revolution” narrative. I bet if he got 100% hit rates on both bodies it would all of a sudden become “gospel truth.”

    Also: I’m pretty sure both Tony and my own standard for acceptable focus is tack sharp while pixel peeping.

    The free market is a wonderful thing. You want EyeAF? Go buy a camera that has it. Someone else wants long battery life and OVF? They have their choices to. Stop treating it like a religion.

  • Per Inge Oestmoen

    I find it hard to recommend mirrorless with manual lenses. With manual lenses, there is no way for the camera to perform wide open metering. Thus, even if the camera will meter the incoming light it will be stop down metering – which is hardly what we expect in the 21th century. More often than not, we are shooting with an aperture smaller than the largest one. When stopping down, the viewfinder has to compensate for the major loss of light that occurs when stopping down from, say, 2.8 to 5.6 or 8.0. Then the viewfinder image really takes a hit – dynamic range as well as clarity suffer visibly and even greatly. Wide open metering was progress, no need to regress back to the days of stop down metering.

    Why mirrorless makes more sense for video than stills? Simply because the still image camera with an optical finder has advantages since it does not consume energy and moreover the sensor “rests” and is protected between the exposures. In contrast, with an electronic finder in a mirrorless the finder as well as the sensor is active all the time. This latter system is a must and a matter of course in video, but in still image photography it is a weakness and a constant cause of unnecessary battery drain. Any DSLR will have a considerably longer battery time as compared to a mirrorless camera, given the same capacity in mAh.

  • Devil’s Advocate

    No-one’s going to make a woven fibre-reinforced plastic body for a shape as complex as a camera – complex curves are difficult and it’s too labour intensive. The D750 will be a short fibre (“whisker”)-reinforced plastic body though, similar to fishing reel bodies. There’s no point in using metal whiskers – the fibres/whiskers used in reinforcing plastic are there to provide stiffness, and magnesium is less stiff than carbon or ceramic whiskers. The other unlikely option is a metal-matrix-composite in which metal is reinforced by whiskers of stuff like SiC.

  • Nick Podrebarac

    You’re referencing these percentages as gospel. There are so many variables that you, comparing your anecdotal success rate, is completely irrelevant.

    -What type of shooting are we talking about? Sports shooting? Studio shooting?
    -What are the conditions of your anecdotal hit rate? Sunny day? Overcast? Dimly lit room?
    -Acceptable focus is relative, and you likely have different standards than Tony.
    -How fast are you shooting? Slower shooting rates will tend to have better hit rates.

    I could go on, but your hit rate assertion is meaningless without context, and would be at best anecdotal with context. From your previous comments, and hefty lean on a Tony Northrup chart, it sounds like you don’t have first-hand experience with modern Eye-AF.

  • Basically it’s just being OCD. In general screws kept with the part they held in, and if they are different sizes near the hole they go though.

  • pest

    It depends on the target. Do it with playing toddlers and your hitrate gets a massive hit.

  • Michael Hickey

    I’ve always wondered, how do you keep all of the screws sorted so that they go back in the right place?

  • Stanislaw Zolczynski

    I´ve had the bloody camera in my hand and shutter was closed, dude. Probably yours had open sensor setting used for cleaning. My old Ricoh GXR m-module has that function. As to shutter, you can ruin it by firing it with lens removed and you finger up the cavity. I don`t think weaning face mask will stop tiny mist droplets blown in.

  • Daniel Taylor

    I did not say a thing about video. You seem to be confusing me with Per Inge Oestmoen.

    You’re still describing ‘sorta nice’ features, not revolutionary features. The first IS lenses were revolutionary. IBIS in a sea of lenses with IS is…nice. Really nice if you have a lot of older glass. But the majority do not seem to care that much about IBIS otherwise sales of IBIS cameras would be far higher relative to non-IBIS cameras. (And for the record: I think Canon should add IBIS to both the M and R lines. I doubt they will, and it’s not a deal breaker, but it would be the smart move.)

    I don’t deny that mirrorless camera bodies have some neat innovations. But the religious revolutionary tone by mirrorless fans is…grating. Dare to mention that you prefer OVF or longer battery life and you get crucified because how could you question IBIS or AF calibration? It’s beyond annoying.

  • Daniel Taylor

    Yes, I can get a higher than 75% hit rate by keeping the AF point on the eye myself. Just because you have trouble doing so do not assume others can’t do it.

  • Baconator

    I had no chance to shoot the 3rd generation of the Sony A7 series, but the 2nd one is frustrating with adapted Canon glass. To my surprise the EOS R handles the ol’ good EF lenses better than my two Canon DSLRs. The AF works in pretty much total darkness when the 1DX2 can’t catch anything in focus. The only thing this camera is missing is IBIS for landscape work in dusk without a tripod.
    The weather sealing report is a little troubling. I wasn’t much concerned getting the EOS R soaked in rain a few days ago, but I guess I should! 🙂 It’s still working though…

  • Athanasius Kirchner

    Ugh, you don’t know all the awful kinds of damage that water can cause to a shutter curtain, do you?

  • mtnman1984

    Nice hot take. Various types of polycarbonate and frp are used in industrial power tool construction. I’m sure the Canon is fine.

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