Taking Apart the Canon EOS R5 Mirrorless Camera

Published September 8, 2020

Let’s get one thing out of the way in the first sentence. If you’re here to understand the mysteries of thermal flow in the Canon R5 I can tell you everything I know without doing a teardown: It’s small, it’s weather-sealed, and photo-body cameras have limited ability to get heat out of the camera.

I am NOT a thermal engineer. I believe that it’s better to know nothing than to know what ain’t so. Today, I will take it apart, comment on what I see, show you some fun pictures.

I always speculate some, but I’ll try to be clear about ‘this is what I know’ and ‘this is what I speculate.’ For example, two years ago, we tore down the first EOS R. I showed that there was a big empty space in the camera, about the size of an IBIS unit. That was what I knew. Then I speculated that Canon would NOT put IBIS in their mirrorless cameras because they were so into lens IS.

I am just giving you an example of how much trust to put in my speculations. Or anyone else’s for that matter.

So Let’s Take Stuff Apart!

The camera looks pretty much like the other Canon cameras with the battery door off. That’s the connector for the WFT-R10 wireless transmitter, which is cool: It functions as a 2-battery grip plus provides ethernet as well as wireless connectivity, connecting up to 10 cameras to a server. This is not something I’m interested in myself; the onboard wireless is all I ever need. It seems a cool, albeit expensive, option for high-powered professional-type people., 2020

The battery door itself gives us our first pleasant surprise. In every camera, the battery door is a weak area for leakage. There’s usually some weather-resistant gaskets around the edge, which the Canon R5 has. In addition, the entire flat surface is soft gasket material in addition to the raised gaskets around the edges and hinge area., 2020

The viewfinder rubber comes off next, Canon attaches theirs with a couple of screws rather than a clamp., 2020

Next, of course, comes The Removal of the Grips., 2020

The key to taking off the grips, for those of you doing your own disassembly at home, is to keep as much of the double-sided tape on the grip as you can, which makes it easier to reapply. The grip material surface feels slightly different than earlier models to the touch, but it’s about the same thickness and flexibility., 2020

The cover to the remote control sensor is basically held on by the grip., 2020

And there’s a metal plate covering the area of the card door hinge., 2020

It seems to provide some reinforcing strength, but mostly a smooth surface for the grip rubber to stick to., 2020

Now we have access to most of the screws and can start body disassembly., 2020

The bottom plate comes off next., 2020

The inside of the bottom plates shows us a new thing! We’re used to seeing a bead of rubber felt between the plastic pieces of the body to seal for the weather. Canon now has a soft rubber gasket along the mating edge of the pieces. This is much larger and provides a greater seal area than what we usually see. It seems to be attached to the body (in the old days, I would have said ‘vulcanized’) rather than being glued on., 2020

The same material is used around the openings where the plate seals around other parts. Here they’ve completed the seal for the battery door hinge from the inside., 2020

The metal tripod plate is sturdy and the actual tripod mount replaceable; both of these are things we consider important., 2020

The I/O side comes off next, and again we see that big rubber lip sealing the entire piece. Also, note that both the HDMI and digital out ports are part of the main PCB, so secure your cables; tugging these ports loose will be an expensive main PCB replacement., 2020

Another close up of the sealing gaskets from the side door. When we took these pieces apart, you feel the suction when they disengage. That’s not something we’ve seen in other cameras. The thing about weather sealing is it only takes one weak place to leak, but this sealing seems to be a step up from anything we’ve seen before., 2020

While there are gaskets around the I/O ports, with any port unless the covers are closed, you lose weather-resistant integrity., 2020

Under the card door, there is a thick foam similar to that on the battery door., 2020

And there’s that big rubber gasket where the door plates fit with the rest of the camera., 2020

OK, enough with weather sealing. You know weather sealing is outside my circle of trust, but I might put this within the rhomboid of reduced suspicion. I write off too many cameras from water damage every year to really trust weather sealing. This is good, but weather sealing isn’t about where it is good; it’s about where it can leak.

The next step is to take out the diopter adjustment screw., 2020

And then the back assembly comes right off., 2020

The back has more dials than the original R, but the LCD wiring appears identical; nothing much to see here. Except for the new, coppery colored flex they’re using on the LCD side, but not the switch side. I don’t know why the new flex material, but it is pretty., 2020

As you can see above, a Canon tech made his ink marks when this part passed inspection. Aaron decided to leave his mark of approval, too., 2020

Now we can look into the camera and see the back of the circuit boards. This is immensely more intense and dense circuitry than we saw in the R. First of all, there’s a green sub-board that appears to be about DC power conversion. You can see some hefty wires entering it from the battery compartment. The larger, square chips are TPH8R903NL voltage converters. Over to the left on the black board, the large white chip is a Canon WiFi chip with what looks like an antenna plugging in just above it., 2020

I am NOT an electronics expert, but I do know DC-DC conversion boards have to generate waste heat. How much depends on load, but I’m told 10%-20% of wattage isn’t unusual.

The viewfinder comes out next., 2020

I’ll indulge in my flex fetish and show you a closeup of ‘the argyle flex’. We actually decorate our office with large printed macros of pretty flexes and circuit boards. Yes, I know I need some counseling., 2020

Anyway, with the viewfinder out, the top assembly comes off. Not much different, other than the number of buttons and dials, from the other R top assemblies. Except they’ve put all the connections between the top and motherboard in a single flex; usually, there are several. There is also, compared to the main part of the camera body, a bit of air up here., 2020

The weather sealing is different around the top assembly compared to the rest of the camera. Where we had those hermetically rubber seals along the bottom and sides, we don’t see them on the top. On the top assembly, there is the traditional ‘top plate sticks out over the body plate’ thing., 2020

With the standard foam sealing strips over some of the body plates. So we have the regular overhang and foam sealing on top that gives rain protection, but the bottom, the part you might set in a puddle, is tightly sealed. It makes sense unless we missed a leaking point on the bottom., 2020


There’s not much sealing material over the lens mount area, though, so if there’s a weak point in weather sealing, I guess this would be it., 2020

TOTAL SPECULATION: Maybe the looser sealing at the top, where heat rises, helps heat get out. The chassis is not a huge heat sink, and it’s wrapped in insulating rubber grip material. It radiates heat, of course, you can feel it, but that’s not an uber-efficient way to get rid of heat.

Now we turn our attention back to the main body. That accessory board comes off easily. It’s a single surface board; the backside is smooth., 2020

And a single view for those who do chip quests., 2020

There’s an aluminum heat sink or electronic shield beneath that board., 2020

Electronic shields tend to be quite thin, but this is a manly piece of aluminum, 0.98mm thick. I speculate it’s more about heat than electronics. Notice I said ‘speculate’., 2020

The aluminum shield connects to copper tracings at the top and bottom (and the bottom tracing connects to the metal base plate), plus it sits above the two thermal pads, so I’m feeling pretty comfortable that this transfers some heat., 2020

Peeling back the heat transfer pad shows the four SKHynix SDRAM chips we’ve already been told are there surrounding the main CPU., 2020

We took off the tripod plate next (note, we had to take off that top heat sink before the tripod plate, so they are indeed connected). Notice the tripod socket is screwed, not soldered, to the plate, so it’s easy to replace., 2020

Now we can get a glimpse of the stabilizer/image sensor arrangement. There’s not much air down in there, particularly if you compare it to the original R., 2020

As long as we’re looking around the edges, I should show you the battery door switch, since people have been having a grand old time stuffing things in there to make the camera think its door is staying shut. This is a small, frail switch soldered directly to the motherboard and only held on by the solder. I have it on very good authority (my own) that it’s easy to dislodge the switch from the circuit board with just a little bit of torque, requiring a complete mainboard replacement, which is very pricey., 2020

Having completed our camera body tour, we took out the main PCB., 2020

There’s another big aluminum heat sink on the underside. This one has a layer of electronic insulating tape over the sensor., 2020

Removing this shows another thermal pad underneath the CPU. So it seems Canon is sending the heat from the SDRAM chips to one sink, and from the CPU to another. To some degree. (Get it? Degree?), 2020

Both card slots are part of the main PCB, but we can remove the ejection mechanism for the CFExpress card, getting a look inside. Here you go; a picture of the inside. You can see why we think CFExpress is a lot sturdier than the long, bendable pins of old CF card slots., 2020

Going back to the camera, we get to see the back of the sensor / IBIS assembly and the huge flexes leaving there, as well as the shutter mechanism between the sensor and the battery compartment., 2020

The sensor assembly is held in by three screws. As you can probably see, Canon has changed to shimming the sensor for flatness (in the R they used spring tension screws). Spring tension screws can theoretically be more accurate (depending on how accurately they measure), but I assume the vibration of an IBIS unit could loosen them over time; every IBIS camera we’ve opened uses shims., 2020

The sensor / IBIS unit comes out as a single piece., 2020, 2020

The shimming for this one was 0.45mm, 0.45mm, and 0.24mm, so a pretty significant tilt compensation was made. And no, that’s not unusual for any camera., 2020

The only thing really left in the chassis is the shutter assembly, which is held in place by screws and posts., 2020, 2020

These we don’t take apart, but then neither does the service center these days. Nobody’s got time to line up all the gearing, plus if you mess with it, you have to have factory software to recalibrate the timing., 2020


With the shutter out, the chassis really has nothing left inside but the lens mount, battery case, and a few connection traces. You know something I’ve found interesting in all the jumping-to-conclusions about heat inside the Canon R5? Not one person has tested the heat conductivity of the chassis. (Spoiler alert: it doesn’t conduct heat well.), 2020

Outside of the chassis sits our sensor and IBIS unit, which I’m quite interested in., 2020

We aren’t going to get majorly aggressive here, but we’ll take off the cover plate., 2020

Which comes off easily along with the outer self-cleaning glass plate., 2020

We can’t get an exact glass measurement without taking the sensor apart, and we have a bad habit of breaking glass when we do that, so it will have to wait for the first Canon R5 to die for a more accurate measurement. We estimated the total (including the front piece) at about 2mm, which is Canon standard., 2020


I also wanted to look at how the sensor is supported in the IBIS unit. We’ve found some fractures in cameras where the sensor is supported by several screws-through-plastic-tabs. There is one screw tab you can see above, but that was mostly for the cover plate.

On all the edges of the Canon unit, the sensor is mounted directly to IBIS plate; no tabs. That doesn’t mean it can’t break, of course, or glue come loose. But this seems sturdier to me., 2020, 2020


On the IBIS itself, we can see the permanent magnets; the electromagnets are shielded here, so not completely obvious., 2020


So What Did We Learn Today?

Not much that was surprising. What with the IBIS unit and a more intense chipset, the camera is pretty thoroughly filled up, there are lots of parts and not much air. There’s a new weather sealing method in the lower 2/3 of the camera that seems to give a really, really tight seal. And there we some pretty new flexes which matters not a tiny bit to anyone but me.

The IBIS unit is very compact but well-engineered. There are no tab connections that might be weak points; the sensor is connected to a flat plate around all its edges. That doesn’t mean there can’t be problems, of course, this is a new build, so we won’t know for a year or so.

There seem to be two separate heat sinks, one under the voltage board, another between the main PCB and the sensor assembly, with thermal pads to direct heat to each. At least one of them connects to the tripod plate, which might provide a secondary sink. This is a lot of heat sink compared to most photo cameras, but not even a fraction of what we see in a video camera. What I can’t tell from this is how that heat then gets out of the camera. It’s sure not air circulation.

Given how tightly sealed things are, I’m curious as to where the heat goes to get out of the camera; some further investigation is required there. A lot of people are talking about how the heat should move around inside the camera, slapping some thermal paste around, and doing things to manipulate the heat cut offs.

I’m a simple person. All I can think of is, ‘how does the heat get out of the camera?’ Sure it goes into the metal sinks, but once they heat up, then where? In a small photo camera, there’s not a lot of ventilation/convection current to get let the heat out. This camera is better sealed than most; I doubt there’s very much ventilation at all.

Somebody should look into that.


Roger Cicala and Aaron Closz

September, the ninth year of 2020



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
  • Brandon Dube

    That’s basically the hollywood/panavision business model. I think rentals start at $10k/wk, custom lens sets go for ~$2-5M.

  • Roger Cicala

    Thank you, that makes perfect sense. I learned something today!! That’s why I do this blog, because I learn stuff!


  • Olandese Volante

    Thermal conductivity is very much analogous to electrical conductivity, so the thicker (more cross section) and shorter your conductor, the lower the (thermal) resistance and the lower the temperature difference (analogous to voltage) across it at a given heat flow (analogous to current). In fact one can make simple thermal models in circuit simulators using resistors and capacitors, the latter to simulate heat capacity. Hook up a current source as your heat source and Bob’s your uncle.
    That said, my guess is that hooking up any type of external heat sink would require a considerable cross section of copper in order to be of any benefit. Plus the existing heat sink being aluminum, which isn’t easily solderable. One might replace the existing sink with a copper one and extend it out through the bottom of the camera.
    Heat pipes can transport prodigious amounts of heat in moderate cross sections but the preferred orientation is with the hot end below the cold end. They will work reasonably well with both ends level because they use capillary action to return the working fluid to the hot end, but they lose efficiency quickly if the capillary action has gravity working against it. So if you’d want to stick a heat sink to the bottom of the camera you’d have to operate the camera upside down for the heat pipe to work.

  • Roger Cicala

    We did; the barrel extended switch was supposed to go in pointing one way, we pointed it the other. It was . . . . fine. Decent images, not great but decent. Easy to carry around, AF was pretty accurate which I was worried about.

  • Athanasius Kirchner

    Roger, this is kinda OT – did you manage to reassemble the 600mm DO correctly? And if you/Aaron did, how do you like it?

  • Athanasius Kirchner

    Ah, that makes total sense.

  • I have read that the internal temp reaches well above 140F, could this be the reason for the overheat warning? I guess a temperature that high would actually mean that the camera is overheating. Shocking.

  • Zak McKracken

    So, me being an engineer and all, I can’t help but think of ways to improve the heat management, so here goes…

    * We can forget about air. Air in such tight spaces doesn’t move much, and even if it did, it conducts heat much worse than any metal, and all it could do is get the heat to some other part of the housing.

    * Heat pipes would be nice, but I suspect that there is just not enough space to use them.

    * Any heat leaving the camera has to go through the housing (or the ports, or the lens, or …). This means the best hope to cool that sucker is to give it as wide a path to the housing as possible, preferably multiple ones. Except maybe you’d like to avoid going through or close to the sensor because that’s bad for your pictures. Not sure what the housing is made of but both Magnesium and Aluminium are fairly good for conducting heat. If it’s plastic, then that would be a big error on Canon’s part.

    * If those power electronics on the first PCB generate any significant amount of heat, I wonder why (or if?) they’re not thermally connected to the case directly. That would be the quickest way to get them some cooling.

    * Same thing for the first heat spreader: Couldn’t that be connected to the back? Much shorter way, much less “congested” because the other heat spreader can’t (easily) get to the back of the camera. Most people flip the screen out during filming, so it’d go through a region most users don’t even touch.

    * The metal base plate to which the two heat spreaders seem to be connected, is not actually the base of the camera housing. So I wonder how well it’s thermally connected to the bottom plate. Maybe a thermal pad/paste between those two could help? Would be interesting to see how warm the bottom of the camera gets in operation, compared to the metal plate holding the mount. Anyways, because both heat spreaders connect to that plate, I bet it’s a bit warmer (thus taking up less heat) than it would be if the first heat spreader went elsewhere.

    Looking at the IBIS-shaped hole in the EOS-R teardown, I’m also kind of thinking that it may exist either because Canon wanted to design the other parts so that they could re-use them in future cameras with an IBIS system, or because they had planned to have one, planned around it but then realized a bit later that it wasn’t going to be ready. If the latter is how they develop cameras, then I can also easily imagine that a decent part of the thermal management here was not designed into the whole assembly from the start but added later, which would have made many potentially better solutions hard or impossible because it would have required them to redesign other components to accommodate them (probably while under huge pressure to get this thing to market already…), and that sort of thing becomes really hard when you have multiple teams working on those other components …

    Anyways, I’d be super-interested to see the temperature distribution on the outside of that camera when it’s getting hot, and also on some of the interior components.

  • Foma Akvinat

    Now that’s really hands-on experience…

    With sales shifting online, is there any room for a company that would provide hands-on time (not That extensive obviously) for people choosing cameras and lenses. Something like photo gear Disneyland? Some visitors are choosing next camera, some just came to shoot with exotic gear once in a lifetime… Could Lensrentals be that company?

  • Olandese Volante

    Diecast metal usually does have quite a bit more surface roughness than rolled sheet, even when the die doesn’t have obvious tool marks from machining etc.

  • Olandese Volante

    MgAl diecast alloy is dull whitish gray (machined bits are somewhat more shiny), but the inside of the shell doesn’t look like bare alloy. What we see here is probably a primer coat. Most MgAl diecast alloys do need a primer coat if you want to paint ’em because otherwise the paint is likely to come off very quickly.

  • Roger Cicala

    I don’t know many things, but this I do know. There is absolutely no way putting that fan on the back of the R5 is going to make a difference. They may release it, they may sell it, people may buy it. But it’s not gonna work.

    UNLESS they plan on cutting off the back of the camera in that area and even then I have many serious doubts it has much effect.

  • Roger Cicala

    Yeah, I’m not sure about the diameter of heat pipes. You could certainly do something on the order of running, say, 16 gauge copper wire between those plates, but not anything much larger than that.

  • Roger Cicala

    All of the above. I guess I just couldn’t choose one.

  • Olandese Volante

    Apart from the difficulty of resoldering the switch, it’s not unlikely the solder pads get ripped off the PCB which, apart from heroic attempts at repair of questionable reliability (guilty, me) means the PCB will be a write-off.

  • Olandese Volante

    Someone found the RTC* chip (in the R6) and called it the “Overheat Timer Chip”. I almost fell over laughing.

    * for those not familiar with the jargon, RTC stands for “Real Time Clock”. It’s the thingy that makes it possible for the camera to put the exact date and time when a picture was taken in the picture’s EXIF data. Every digital camera has one. It’s always running even when the camera is off or the battery is out because it’s powered by its own little coin cell.

  • Shane Castle

    “And there we some pretty new flexes…” Hmm, we’re missing a verb. “Saw?” “Found?” “Admired?” “Discovered?” “Drooled over?” 🙂

    As usual, an entertaining and informative teardown.

  • Kai Harrekilde-Petersen

    The connector just above the WIFI module looks deceptively like a standard u.FL connector used for WIFI, GPS and several other types of antennas.

    As for the new sealing, it could very well be that it is molded onto the plastic (2C molding).

  • Scott

    Ha Ha, very good Roger, I missed your sign off until now. “September, the ninth year of 2020.”
    It sure feels like that!

  • Roger Cicala

    In theory, I’m sure it could, but it requires some expertise and not just your usual soldering iron to resolder to board traces (these aren’t through the board, they’re surface mounted). We don’t have either here.

  • Glenn Ruhl

    Roger, this may be an ignorant question, but it’s something I’ve been wondering about. You wrote that the battery door switch is soldered directly to the motherboard and only held on by the solder, and can be disconnected from the circuit board with just a little bit of torque, requiring a complete mainboard replacement, which is very pricey. Why can’t it just be re-soldered to the board?

  • Scott

    I agree. Its like a styrofoam cooler in my mind. The contents stay at a given temperature for a long time whether or not the cooler is sitting in the sun. However, I would expect some difference, and maybe there is, just not enough to make a marked change in cool down times. Either way, it’s a pretty remarkable camera. I gave up on Canon a few years ago, but they’ve certainly created a compelling camera.

  • Michael – Visual Pursuit

    I was laughed at when I said four years ago that I would prefer a camera without IBIS, because IBIS would mean cooling problems. Now folks got their IBIS, and my cooling problems. Too bad. An air gap is the working principle of many thermal insulation systems. An air gap is also found around moving sensors, as in IBIS (I Boogie, I Shake).


    I’d pay a premium for a R5 variant without IBIS but a heatpipe 1D-X Mk III style.

  • RNG

    Yes it is so, but for fast cooling, you would need to get the internals cool fast. There’s quite a lot of barriers here to reach the point where cooling placed on the outer shell will actually start cooling the internals quicker. It is not helping that the internal air will actually act like a heat insulation, as air is a bit reluctant to release its temperature (copper has thermal conductivity of 384, air has 0.026).

    So to effectively cool it fast, you would need to get your hands directly on the heat sink and apply the cooling on that. Otherwise it will take some time to dissipate it via the outer body shell, even if trying to speed it up with cold backs etc.

  • Brane212

    As I suspected, there is place for better cooling of electronics.
    Both of those aluminium parst should have small heatpipes and heat conductive path should lead to bottom side, where the heat can be further dissipated, if needed.

  • RNG

    Indeed. But nevertheless, more mass, more heat capacity the object will have. So making something physically bigger will help. Even better if in the process one can increase the surface area to the outside, so the piece can more easily to release the heat.

    But on the other hand, the bigger the thermal capacity, the longer it will get it cool again, once the limit of thermal capacity is reached.

    I guess this might actually be one of the R5 problems. There’s way bigger mass in the cooling elements than usual, so it will consequently also take longer to get them enough cool again, once the limit was reached.

  • RNG

    It would definitely help. Obviously the more material to transfer the heat, the more effective it would be. Even better if something like heat pipes could be used that will internally transfer the heat via gas-liquid exchange, which will be one of the most effective ways to transfer heat, as the liquid boiling to vapor binds a lot of heat quickly.

  • Scott

    I understand your point, however, employing an active cooling method on the outside of the camera should reduce the internal temperatures faster than not, shouldn’t it? I realize that we are talking about chips buried in the middle of a poorly conducting body, but it seems to me that actively cooling the exterior will allow the insides to dissipate heat quicker. The cooled exterior will create a stronger gradient than doing nothing so I would expect some shortening of the shut down period, even if only by a few minutes.

  • RNG

    The IC temperature will be totally different than what you measure from outside.

    The thermal limits of IC won’t be linear either, so it will allow you to reach temps like 95 degrees internally, until it shutdowns, but then you need to reach steady 70 degrees internally to again continue. Once you get the heat shinks up to the temps that the 95 degrees is reached, you’ll have to wait quite some time that the IC can again operate for longer periods.

    Also, the IC temps will have different ramp up angle than the body temp, so IC shoots up fast in heat, the cold heat shink will cool it down until it gets saturated with heat, and hence you will need to get that heat shink cold again in order to continue. Once you turn the IC on again, it will immediately start heating it up again at that high heat rate. It is like heating a big piece of iron with a blow torch. Held the other end of the iron with your hand, and start to heat it up from the other end. Once your fingers start to burn, stop, and see how long it takes until you can again start heating it up for longer periods without your fingers burning.

  • RNG

    First the conduction happens from the ICs to the heat pads and from the there to the heat sinks. This is by far the most important part of the cooling, at will even out the hot spot of heat that forms inside the IC that the IC cannot tolerate.

    The next task is for the heat sinks to transfer the heat to the surrounding panels. Either via direct conduction (screws and other physical connections), IR conduction, or air conduction.

    Only place where convection here can help would be to exchange that hot conduction via air into colder air. That would be convection heat transfer. Now, the heat capacity of those big heat shinks is so much bigger than the air around them, that if you exchange that air passively, the amount of reduced heat exchange will be quite minimal in comparison to what those managed to radiate via conduction. Hence the final conduction surface to the open air will be the outer panels of the body.

    I frankly do not believe this camera cooling can be any further improved internally, except by making it bigger. And obviously SW and HW updates in further iterations can reduce the thermal load overall.

    Attaching a peltier element to the bottom might definitely help. Looking at the body and the heatshields, I’d say the best place to cool this down is the area behind the screen, though. The IR conduction of those heatshields will mostly hit the rear panel, and it also has most surface area against the hot air inside.

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