Investigating the Canon R5 Heat Emission

Published September 10, 2020

ADDENDUM: I should have mentioned in the text, all testing was done at 73°F (22.75C) ambient temperature. 

Lots and lots of people are talking about Canon R5 heat cut-offs. The discussions range from technical discussions about heat generation, cooling methods, and firmware protocols to strident conspiracy theories.

I only know a little bit about heat:

  1. Electronics give off heat when they’re working.
  2. Heat fries chicken, which is good, and fries electronics, which is bad.
  3. You can get rid of heat by conduction (flowing through nearby materials), convection (circulating through gas or fluids), and radiation (which mostly occurs at high temperatures). We know from the teardown that the R5 is tightly sealed, so we have to figure that convection doesn’t play much of a role.

As a repair and QA oriented person, I hate bricking cameras. So I’m less interested in coaxing the camera into working hotter (see point 2) and more interested in how the heat gets out. When we did the teardown of the Canon R5, we saw some metal heat sink/transfer plates that would conduct heat away from specific chips, but once the heat sinks get hot, then what happens? That’s what I was interested in.

This is not rocket science; there are people far more qualified than me talking about chip operating temperatures, the thermal flow of various substances, firmware cool-down cycles, and stuff like that. (There are also people far less qualified than me talking about those things.) I have nothing to add to either of those discussions, and I don’t intend to get into a fracas about it.

This is just some fundamental stuff about how heat leaves the camera—because to my simple mind, getting the heat out of the camera is the end-all, be-all. Tweak heat flow as much as you like inside, and maybe you’ll gain a few minutes of this or that. But eventually, the heat has to get outside, or the camera needs to shut down. I do need to point out that the heat flow with the back off has nothing in common with the heat flow with the back on, so I’m doing this with fully assembled cameras.

First Step

We got a Canon R5 running V1.0 firmware, slapped a CFx card in, put it in 8K mode, and ran it to temperature cut-off, using some industrial thermometers to see where heat left the camera.

With the lens on, and the camera sitting on a table, all covers closed and LCD folded against the camera back but not on we ran it for 18 minutes before getting a temp warning. The hottest part of the camera was the back behind the LCD door (43°C / 109°F), followed by the rear body around the command/set dials and the area of the grip where you rest your thumb (40°C / 104°F). The bottom plate around the tripod socket reached 38°C / 100°F.

The top, front, and sides didn’t warm up much at all; most of the camera was around 30°C.

We redid things with the LCD moved to the open position, away from the camera. This time that area on the back of the camera was a bit cooler, 39.5°C / 103°F, but nothing else changed much. So a few takeaways: First, leaving the LCD open lets the camera radiate heat a bit better, which is pretty logical, but not better enough to prolong recording time. (We did use the same CFx card for both runs.)

Next, we waited until the camera cooled enough to record again and restarted. The only interesting part of this was the second shut down occurred at a degree or two lower external temps than the first. Is this because of the delay in getting residual heat out of the insides? The inside should be hotter than the outside, because thermodynamics, but I couldn’t measure how significant that difference was.

At this point, we decided that the thermometers we were using were reading from a 1cm² area, which was kind of a blunt tool. So I got a little FLIR IR camera, spent some time checking it’s readings against both of the thermometers we used, and decided it was just as accurate and gave us a lot more information. Plus, cool pictures that are more fun to look at than rows of tables.

The Chassis and Shell

The chassis and shell of most cameras have been developed for years to be strong and light (most manufacturers use similar material). I’ve never thought they conducted heat well, but I didn’t know for sure.

So we took a shell off to test this a bit. Just simple stuff; I used a narrow-gauge heat gun to heat the shell and see what happened.

First, we heated the inside of the shell with rubber intact and tested the temperature on the other side. We found that the shell is indeed not a great heat conductor. Heating the inside up to 180° F / 82°C the outside got up to 160° F, but with several seconds delay. With the rubber grip applied the difference was, as you would expect, a bit longer, and the outside reached about 150°.

Then we heated one corner of the shell looked to see how far the heat spread. We knew heat crossed the 2mm thickness of the shell slowly, so I figured it wouldn’t conduct heat to other parts of the shell very well. For once, I figured right.

We had to go back to our industrial thermometers for readings here; the spectrum was more than our little camera could handle. But I’ve got that bottom corner heated up to 180° F, the rest of the shell isn’t very hot at all., 2020


I kept the corner hot for a few minutes, and we did get some local spread, but I’m not sure if some of that was leakage from my heat gun. It’s very clear, though, that the shell material doesn’t spread heat especially well. If this was aluminum or copper, the whole shell would have heated up. Obviously, it does pass heat out of the camera to some degree, but it sure doesn’t act as a heat sink or anything., 2020.Hot

One other point of interest, the shell held heat pretty well. Even exposed to air, it was over 10 minutes before it cooled down to room temperature. This kind of poses the question that if heat isn’t getting out of the shell very well, then how does the heat get out?

Looking at the Heat

We got another Canon R5 with firmware v1.0, put a CFx card in, opened up the LCD, and started recording 8k again. Within a few minutes, we found our warm spot on the back of the camera., 2020

I overlaid an image from our teardown on the thermal image to show what’s right below there. Duh, the area over the processor and SDRAM cards., 2020  Please note, because someone is going to claim otherwise: this is NOT an image with the back off. It’s an image of inside of the camera overlaid on the heat image to correlate location. 

There was a little warmth on the front., 2020

The top remained relatively cool. I had wondered, with the camera sitting on its base, if there might be some ‘heat rising in air’ effect. But then, as the teardown showed, there’s not a lot of air in there. We seem to be seeing a ‘viewfinder blocks heat transfer’ effect., 2020

The bottom of the camera got a bit warmer, so it seems like the heat sink that’s connected to the metal tripod plate is sending some heat that way., 2020

After a while, the warm fuzzies started giving way to the screaming heaties. Here are some pics showing how the camera was lighting up as we approached thermal cut-off, at 20 minutes.

The bottom is my favorite in this group. Notice how every screw that goes into the metal tripod plate is lighting up. The lens mount ring is pretty hot, too, with a temp of 38°C. The tripod socket seems to actually be a bit cooler than the rest of the bottom plate. I’m not sure why, perhaps a different metal, a gasket where it connects to the tripod plate, or possibly because it sits in a little air pocket inside the camera., 2020

The top assembly still isn’t very hot in general, but both of the metal camera-strap lugs are spewing heat., 2020, 2020

The hot spot at the back peaks out at 42°C and the entire back warms up to some degree., 2020


We have some significant heat radiating from the front, too, particularly around the lens mount area and in the corner above the card doors., 2020

The hottest spot in the camera, though, was clearly the CFx slot. After the card was ejected it was about 48°C., 2020

After Firmware Upgrade

We got a longer run after upgrading to V1.1, getting 25 minutes before cut off, but at the expense of slightly higher temps. (Full disclosure: I didn’t tell Joey to use the same CFx card in every run, so that may have changed.)

Not surprisingly, the longer run times came with slightly higher temperatures. Only a half degree hotter at the back., 2020

And at the bottom., 2020

The card slot is quite a bit hotter, though., 2020

Of course, the card was hot, but I figured someone was going to ask, so here. It reads cooler than the slot, but it took a couple of seconds to get it out and get the image, so I’m not sure if it actually was., 2020

This made me curious about how hot the I/O ports were. The port covers had remained closed during recording. The ones on the mainboard were quite hot; those on the sub-board not hot at all., 2020

The sensor radiated quite a bit of heat, too. It wasn’t as hot as the card slot, but has a bigger surface area. It may also be that the metal in the IBIS unit is hot and that’s leaking out through the sensor area., 2020

A friend, who wants no part of the inevitable arguments a Canon R5 heat post causes these days and will therefore remain nameless, was kind enough to read the internal temperature from a raw file taken when we were doing these other measurements. The EXIF recorded internal temperature was 63°C (I originally typoed this as 61C, it has since been corrected), which is hotter than even the CFx card slot.

I don’t know which temperature sensor the EXIF reads or where it is located. But somewhere inside the camera is hotter than the CFx card, and way hotter than the outside of the camera. There has to be a gradient, of course, for heat to flow. Still, this seems to indicate heat isn’t flowing easily.

So What Did We Learn Today?

Odds and ends mostly. The answer to the question “how does heat leave the camera” is basically not very well, and mostly via the metal parts. ‘Mostly’ as in the temperature is higher there, so I assume the heat flows easiest to those metal parts. I don’t have the math to figure out the actual caloric transfer, and the ‘not metal’ parts have a bigger surface area, so it may be that most of the calories may exit through the shell. The camera is hotter deep inside (the temperature sensor) than at the hottest exit points.

I am NOT a chip guy, but according to their faq, the Toshiba voltage converting chips have a suggested maximum operating temp of 60°C before they dramatically lose efficiency, and less efficiency means generating more heat. The CFx card slot was at 57°C and the internal temperature sensor at 61° C when things shut down. That could be a coincidence but may suggest Canon doesn’t think getting the inside much over 60° C is a good idea. I don’t know, but I’m a conservative guy by nature, so my personal decision is I’d prefer not to get the inside much hotter than that.

I’m not going to comment on how to improve heat transfer deep inside the camera; other people seem to be working on that. But the camera is a lot hotter inside than it is outside when it shuts down. If it doesn’t get heat out very well, it certainly can’t be expected to cool down quickly after it turns off from overheating. Cooling the outside of the camera should help a bit, but it’s not going to be very efficient.

Leaving the LCD opened away from the camera back, opening up the HDMI port cover, and saving to SD cards when possible (not an answer for 8K video, I get that) may all help get heat out of the camera while you’re using it. Still, I doubt it’s enough to make a significant difference in recording time. Removing the rubber grips might help a bit, too, but probably not a lot; the shell isn’t a great heat conductor., 2020

It seems likely that taking off the lens and opening the shutter, opening the card doors, and removing the CFx card will speed cool down. (I think several people have already discussed that online). But that’s all I can think of that might help a stock camera stay cool, and none of those are impressive thoughts.

Some people intend to do more aggressive things to extend recording time.  It would certainly be possible, with some minor modifications, to connect the metal heat sink plates to the outside world. You might do so by just exposing the bottom tripod plate and attaching a sink to that. Of course you lose weather sealing, but it would be simple to try. I don’t know enough about the effectiveness of thermal transfer to say, but you could run thermal tape under all the bottom screws and bring it out through the bottom plastic cover and attach it to a heat sink. If that’s effective, adding some more paths to the two other heat plates in the camera might be even better.

You could also ventilate the camera to outside air fairly easily. There’s a large area in the body’s back plate that could be opened up; there’s no electronics under it.  There are some smaller areas on the front plate where this could be done, too. It would be a fairly simple matter to take all the weather sealing out and make some leaking places for air to circulate. I honestly doubt some air circulation is going to have much of a cooling effect, but again, I don’t have this kind of maths. I bet some of the commenters will, though.

There’s also the issue that the camera is hotter deep inside. I suspect that when some third party does good work to improve heat transfer (where there is demand, an entrepreneur will fulfill it), that work will have to include some modifications of the internal heat flow. That won’t of itself be enough; you’ll still have to get the heat outside of the camera to accomplish much.

These kinds of things would make for a bigger, bulkier camera with no weather sealing—sort of a redneck 8K video camera.

Given the low price of the R5 compared to a dedicated video camera with these specs, I expect someone will probably do it. Not me, I’m out of the entrepreneur thing, and a lot of experimenting (AKA camera sacrifice) would need to be done to figure out the most efficient methods.

I just can’t imagine tossing a fan on it and / or making a few holes is going to be effective. Someone will Kickstarter the idea, of course, but that doesn’t mean it’s going to work. Someone is raising a bunch of money on Kickstarter and then not delivering a working product. Who would have thought that could happen.

And Now, We Shall Have the Speculations!

Speculation is not knowledge.  Robert M. Price

For a long, long time, the engineers making photo cameras have been worried about better weather sealing and materials that are strong and lightweight. They have not been particularly worried about getting heat out of cameras.

A big camera has many different development teams, each doing its own thing when it designs a camera. Let’s guess that the team doing electronic and video capabilities managed to cram all this super video goodness onto chips. Surely the marketing team LOVED the idea.

Some other team probably said, ‘it’s gonna be hot in there’ and got told, ‘put in some heat sinks and transfers and do the best you can.’ That was done, we’ve seen it. Perhaps it could have been done better, but there was a lot of new stuff going into this camera, which probably meant a lot of compromises had to be made, and deadlines had to be met. (Actually, deadlines were missed, they always are, and the pressure mounted.) In the end, I bet that everyone agreed 15-20 minutes of 8k video was better than 0 minutes, and well, deadlines!

The body design team has been working towards the goal of light, strong, weather-resistant for about 15 years. A new casing material, openings to allow air (and therefore water) to flow through the camera, external heat sinks, that stuff wasn’t going to happen. Not only would you need to find new material, but you’d also need a new plant to make the parts and a redesigned assembly line, too. And nobody was going to hold up the release for another year while they redesigned things.

Is Canon going to “fix this” as people keep saying? I doubt that’s possible, and I really doubt Canon thinks it needs fixing. I believe they consider it primarily a photography camera that can shoot some video. There may be another tweak or two, but I speculate that operating temps have to be kept at some level, and that cool down is always going to be slow.

A firmware hack or update isn’t going to make the camera cool better; it’s going to allow it to work hotter. I think that probably isn’t a good idea, but I could be wrong. I’m wrong a lot. (Do you know what I do when I’m wrong? I say, “It looks like I was wrong about that.” Some of you all should try that. You’ll be surprised to find it’s not painful.)

Other people are certain this is a purposeful firmware crippling, and a hack will fix it. That will mean the camera can really operate at higher temperatures. It might be they are right. Things may work fine in there at 70°C or even 75°C (167° F).

Will the Canon R5ii someday have better heat management? It’s possible that Canon won’t give a damn since they consider this a photo camera with video capabilities, and it’s not a priority. I suspect, though, that Canon engineers are like me; they don’t like the idea of unescaped heat in a camera and will improve the heat flow on general principles. But that’s someday, and I’m living in today.




Joey Miller, Aaron Closz, and Roger Cicala

This 11th day of the 9th year of 2020


A Note for Leaving Comments: We have polite discussions and disagreements here, backed by logic, facts, and, when possible, science. If you want to scream your viewpoints or make personal attacks on others, there are plenty of forums where that is the main method of communication; please take those comments there.

Another note for those about to suggest more tests: You can buy a nice little phone mounted IR camera for just a few hundred dollars. You should get one and do those tests. I’m like a squirrel, I have a short attention span and get bored easily. I’m over this heat stuff.


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
  • It would be interesting to take the cards out and record externally which seems to work forever without overheating and then do these temperature readings again. Why does it overheat only when we have cards in the camera? Does the extra airspace solve the problem or is it because the circuitry for reading cards is active if they’re in even if they’re not being used?

  • Roger Cicala

    That makes sense, but I don’t know if anyone’s really looked at it.

  • Monic

    May I ask a question related to all mirror-less cameras? Given that the sensor is always downloading data to the optical viewfinder, it appears it will be hotter than a DSLR sensor that is off most of the time except when taking a photo or when live view is active. So the question is, since the mirror-less sensor is hotter, is the noise floor for mirror-less cameras always going to be higher than for a DSLR camera? Or more simply – is the noise performance of a DSLR better than a comparable mirror-less camera?

  • Tnos Hosten

    well… here’s some noise diagrams comparing the noise of the EOS R vs the R5. 10 minute dark exposures, ISO 100. In camera long exposure noise reduction off. This depicts the pixel value noise of the RAW files.

    This compares the noise of the R with the R5 first image taken with both cameras.

    This shows the R (hottest temperature after several long-time exposure images) vs. the R5 after 1,2,3,4,shots and after recording a 15 minute video (EXIF temperature then at 54°C!!!).

    Now, that was firmware 1.0 on the R5, we had not done the comparison after that.

  • Zak McKracken

    Based on the pictures with the newer firmware, showing that the case gets a little hotter but the card slot heats up lots more, I wonder if the firmware update might not merely increase the temperature limit but also reduce power consumption (this heat production) on some of the components (but not the storage system).

  • Zak McKracken

    »it has been verified that putting the camera in a freezer reduces the recovery time«

    You don’t say! Putting things in freezers cools them down? That changes everything!

  • Zak McKracken

    Simple physics say that if you increase heat conductivity, you achieve the same heat transfer at lower temperature differences. (Or more heat transfer at the same temperature differences). So above a certain conductivity, it should be possible to dump all the required heat without burning anyone.

    This might, however, not be achievable based on the R5’s surface area, with the case material it’s made of.

    In addition, (again, based on theory, not the particular design restrictions of the R5), you only need to keep surface temperature below (44°C limit for “slow” burns, acc. to wikipedia) in places where the user touches the camera for an extended time. So as long as the grip, the lens and the buttons on the back stay below critical, you could still dump more heat through all other surfaces.

    This means it’s definitely possible to design a camera the size and shape of the R5 which handles heat noticeably better — though it doesn’t mean, of course, that it would have been realistic for Canon (or any other company in their place) to do much better than they have with the R5.

    I wouldn’t be surprised to see them returning to metal cases with their next higher-spec models.

  • Zak McKracken

    »sadly making this camera a very bad choice for astro-photographers.«
    I’m not so sure about this. Meaning: it may be correct but we can’t tell. It seems like the sensor on the R5 is heating up to some extend while shooting 8k, but how bad is it when shooting pictures of the night sky? Other cameras with limits on their video record time, or which don’t even offer 8K may be heating their sensors just as much in that scenario, or possibly more.

  • Zak McKracken

    Simple test that might be useful in that context:
    Record video of some test scene until the camera turns off, then analyze the (change in) noise characteristics of the footage as the camera heats up. Depending on availability of S-log, C-log, HDR modes and such, it might be difficult to compare between cameras that way, but that could be solved by stopping the video, taking a raw picture, then continuing (albeit at the cost of a human spending time to do it…) It’d be interesting in how far heat is affecting camera output, and if there are differences between manufacturers/models/firmware versions in this area.

    I’m sure you guys don’t have anything else to do anyway, right?

  • Dean Cho

    Looking forward to seeing in the future how many R5 cameras fail due to the high internal temps damaging the electronics. Also looking forward to seeing how the high internal temperatures affect image quality, such as increased noise.

  • Tnos Hosten

    How could a reflective surface (emissivity << 1) with temperature x spoof a pyrometer with typical emissivity setting of 0.95 to overestimate the temperature?
    Honest question, haven't seen that happening. Granted, he didn't state the emissivity setting.

  • Kai Harrekilde-Petersen

    With the amount of heat going to the tripod mount, I was surprised to find that you DIDN’T try to mount a big-ass metal block (painted black) to the mount. Or at least mount it to an aluminum ball-head and tripod. Should siphon away some heat and dissipate across the nice large surface.

  • Sicofante


    The article is showing what the temperatures are were they can be measured. If the camera overheats or not can’t be determined by that (and the article makes no attempt at doing it), since the firmware stops the camera from recording when the manufacturer deems it adequate.

    We do know the camera does not overheat because a good number of experiments, effectively circumventing the decisions made by the firmware, show it can record much longer than what the manufacturer decided.

    Again: every electronics heats when working. Overheating means it stops working by cause of that heating. This is not the case and the article makes no attempt at proving otherwise.

  • Bing Bing Pow

    Right. This article is fake.

  • Dennis L.

    Is Canon going to “fix this” as people keep saying? I doubt that’s possible, and I really doubt Canon thinks it needs fixing. I believe they consider it primarily a photography camera that can shoot some video.

    Or – if it is primarily a photo camera the fix is easy. Stop trying to make a super duper video camera out of it. Go back to 2K. If you can’t shoot anything because the camera is overheating – it is definitely a problem.

  • Sicofante

    Overheating and heating are not the same. This article doesn’t prove overheating at all.

  • Andreas Werle

    Heraeus for instance makes “Quartzglass”.

    But all this glass is “Synthetic fused silica”. They also produce some glass made of “natural quartz”, namely one called infrasil 301 and infrasil 302. If you read the knowledge base of Heraeus Conamic about Quartzglass you will find that none of this is crystal quartz. It is “quartz glass” which is made by melting crystaline grains.

    Google for “Heraeus Fused Silica Knowledge Base”

    Greetings Andy

  • Olandese Volante

    Well, I didn’t see realistic a need for 8k video, at least not in a handheld general purpose camera body. Yet apparently some people seem to think it’s so essential that they can’t stop bitching about it 😉

  • Brandon Dube

    A FLIR camera is very similar to an IR thermometer in its operating principle.

  • Brandon Dube

    Over, not under.

  • Kufat

    Yeah, no question that decreased TDP is ideal. I don’t see a realistic need for more than 8K video, so hopefully the next generation will be doing approximately the same work with more advanced silicon.

  • Michael Clark

    I’ve stolen that line more than once since reading it all those years ago.

  • Michael Clark

    Not really for its primary designed purpose: shooting sports and action at the cutting edge of current technology.

    It’s one thing to say a consumer grade general purpose camera is still good for taking general purpose photos (i.e. posed portraits in bright light, whether outdoors or by providing enough controlled lighting to accommodate the technical capabilities of the camera) when expectations of what that type of photo should look like haven’t changed that much over that time span. It’s quite another to say a highly specialized camera is still good for shooting sports and action under not so great lighting when expectations of what is possible in that scenario have been grossly inflated over the same time period.

  • I still have my Razer stored away and totally agree! I liked my Blackberry Tour a lot too. I miss the keyboard.

  • The Moto Razer was a better telephone, as in used for vocal communication. But then again, so was my old analog Motorola brick.

    Also the Razer has a respectable Ms. Pac Man port 😀

  • Patrick Chase

    The entire argument was pointless. If the cover glass is spoofing the FLIR such that it underestimates the true temperature of the sensor (which is admittedly possible as you argued), where would that heat go? How would it change the conclusions of the article?

  • Jam005

    But what the FLIR does tell one in conjunction with an IR themometer pointed directly inside of the camera, is that is gets extremely hot. And one can not determine the internal camera body temperature by using their hands holding the camera.

  • Not THAT Ross Cameron

    Satire alert:
    As an unbiased Nikon owner, I decree that the R5 shall henceforth be known as The Hades (as in “hotter than…).
    This talk of electro-wizardry causing the heat is clearly misguided at best. The only logical explanation is the the IBIS is so class-leading it has somehow opened a cross-dimensional portal into said realm and is letting the heat bleed into ours.
    Canon should be congratulated for the thermal shutdown capabilities – it is obvious that they take climate change seriously and don’t want their products to be a contributor.
    Satire alert off.
    Hopefully, with the above comment, we have now jumped the shark on this matter and whole thing can be laid to rest. Wishful thinking?

  • What a fantastic post (and test), Roger. I have one of those FLIR cameras but haven’t run into issues with either my R5 or R6 so I haven’t been inclined to do such rigorous testing, though I truly appreciate that you have.

    The only testing I’ve done was a full run on each indoors (with original firmware) where it performed as Canon stated, then an outdoor test in 15°C cloudy weather after 1.1.1, where they both ran for 90 minutes without warnings or overheating (R5 in 4K HQ 24P to CFx, R6 in 4K 24P). That’s more than enough for my use, and living in Sweden I’ll see more temps below 20 than above.

  • Brandon Dube

    The bonds of the focal plane into its package can become embrittled by rapid thermal cycling. Brittle + shake it around with ibis probably isn’t a great combination.

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