Canon EOS R5 records 4 hours of 4KHQ 30p to an external recorder, with a couple of simple tweaks

Mar 4, 2020
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He says in the review that the camera doesn't get hot on the outside, only moderately warm. This makes me wonder what could be the reason for this, and I cant really make sense of this. If certain components inside the camera indeed overheat to a considerable temperature, say 80°C, and the camera stays moderately warm outside, this would mean those components in the inside must be thermally really really well isolated. It would fit to the observation of a cool-down time of 2h. But who would thermally isolate components inside?

But then, when those components are able to cool down within 2h, this gives us a clue as to the thermal conductivity of those components: if heat goes down by conduction to room temperature within 2h I would assume an exponential heat half-life time of around 1h. Assuming this thermal conductivity, then I can't understand why the camera would suddenly overheat at 4 hours, I would assume the camera would have to approach thermal equilibrium within 2h and should be able to hold that state indefinitely. (equilibrium: Heat in = heat out. If heat gets out within 2h, then all the heat you put in within 2h also leaves the camera within 2h, so if you can go for more than 2h, that should be indefinite equilibrium)

It would be really interesting to see infrared-images of an overheated camera, to see, where the body dissipates heat to. It must go somewhere.

It all makes no real sense to me. I come to the conclusion, this must be somehow software-limited, not actually physically overheating components.
The math doesn't quite work that way. during cooling there is no additional heat source. However, during operation, you have a heat source and the temperature of that source is unknown, but could be quite high.
 
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A little bit more on temperature management of CFexpress cards.
As this article indicates: “In general, we find techniques like throttling, which may be employed to reduce SSD temperature, to be effective at reducing the failure rate of SSDs. We also find that SSD temperature is correlated with the power used to transmit data across the PCIe bus, which can potentially be used as a proxy for temperature in the absence of SSD temperature sensors.”
In other words, at the end of the day, it may be the CFexpress card itself that employs some kinds of power throttling to reduce its temperature, and cause the 8K/4K read/write unsustainable. The difficulty is that different cards may have different heat tolerance and management policies.
Perhaps someone can experiment with different CFexpress cards and report the results here.
For the R5 itself, it would have been difficult to have policies to manage overall temperature for all current and yet to appear CFexpress cards besides the other heat generating elements so a kind of collective throttling (i.e. setting a safe time limit that guarantee the card and the camera will not burn out) was perhaps the only option. Good news is that the R5 is not hot to touch (unlike some other cameras such as XT4, for example) therefore, PCB heat is reasonably managed.
My guess is that, as the newer CFexpress cards with heat sensor communicate their temperature to the camera, better heat management mechanisms and policies will become available via firmware updates.
 
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ahsanford

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Aug 16, 2012
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I think at best this solves one problem but creates another. Because while you now might be able to record longer video you've sacrificed the versatility of the camera. With the additional attachments it would be much more difficult to use it for photography. If you know you'll only need it for one or the other then it's fine, but switching back and forth between the two no longer becomes very practical. One of the big advantages of hybrid cameras is being able to quickly and easily switch between photo and video. Can't do that with a recorder attached (and all that comes with having one)

Still, it is a solution of sorts to the overheating problem.


I don't see this as a solution for any hybrid shooter or photographer who very rarely shoots video -- completely agree. They need to flip a switch and start shooting video.

If this pans out, this will only be a workaround for dedicated video folks. But: that's potentially a big deal, as that camp has had the biggest doubts about the useability of this rig for their needs.

- A
 
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Aug 27, 2019
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I suspect the issue is the Cfexpress card has it's own table for safe operation and if the picture from EOSHD is accurate (I question everything posted on that dumpster fire of a website) the Ram and the Processor are very close to the Cfexperss card so heat is being transferred to the card.

The system likely has a heart beat monitor for the Cfexpress card that is active even when the card is not been written or read from. The heart beat polls the card parameters as well as confirms the card is live and ready to read or write.

So as the Camera operation heats up the CPU and the Ram the card(s) is also being heated until they reach the point were it flags the system that it is in thermal danger and the on screen heat warning it tripped. The Camera does not hit the next stage in the thermal protection cycle right away and keeps recording. The next stage is likely linked to the CPU and Ram temps. We saw this with the live stream Gerald Undone did, the system showed the thermal warning for a couple of hours but did not shut down.

Removing the card might be removing the stage 1 thermal protection trigger. Stage 1 might be overly aggressive and therefore an easy firmware fix. I would also be interested to know if as R5 gets into more peoples hands does card brand change the internal results at all.
 
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Dragon

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Would love to see if 4KHQ external is the same as 4KHQ internal to see if there is a drop in quality/bit rate over HDMI. If there is a drop over HDMI it might explain why it records for longer. Pretty sure the R5 disappointingly doesn’t have HDMI 2.1.
HDMI 2.1 almost certainly takes more power (cable equalizers use power) and power is already a problem. There are always technical trade-offs.
 
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Some people have tried and got slightly longer times than CFexpress. Informal forum posts though

I haven't tried an actual test yet but when I go to 4K HQ w/o a CFexpress card in (only SD) it still says 25:00 min as the limit (rather than 29:59). I will test a bit more though when I have time.
 
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quilatoo

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Jul 30, 2020
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I don't see this as a solution for any hybrid shooter or photographer who very rarely shoots video -- completely agree. They need to flip a switch and start shooting video.

If this pans out, this will only be a workaround for dedicated video folks. But: that's potentially a big deal, as that camp has had the biggest doubts about the useability of this rig for their needs.

- A
Yeah this seems a very fair assessment.
 
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marathonman

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Aug 29, 2016
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While I agree it increases flexibility, I don't agree that it doesn't add much more bulk. You are adding 1.3lbs to the top of the camera if you run a 750 2hr battery or 1.65lbs if you run a 3hr 970 battery. If you add a cage, arm and mount the monitor to the side, that's another 1 lb. In actuality, I always run my Ninja V and camera in a cage just so I can lock my HDMI cables and lock the SSD in so it doesn't pop out. All of those things can dump your shot if it happens while on the move. I've had HDMI cables catch on sliders before, etc.

Don't forget you also need to bring extra batteries just for the monitor and If you are shooting talking heads and need the runtime, you can't just take off the monitor anymore because you will run back into overheating. Lastly, if you then need to take the camera off sticks and move it to a gimbal, you can't just leave the monitor on top or on the side. You have to take off the monitor, rig it on the gimbal below and re-route your cables or you will have no way to balance it. The last issue can be handled with a separate body, but you also need a second monitor as well unless you can keep the thermal limitations in check or move the monitor back and forth.

I think certain styles of shooting can work with external recording, but it is a narrow window without accepting other compromises.
All incredibly valid points. Show me any decision in life that doesn't involve compromises!! Just shooting video on the R5 (and it's fantastic) involves a set of compromises and this whole overheating discussion is frankly absurd. I'm just saying that if it works for you, there are compelling reasons why a Ninja is not that bad an option because of cost and other benefits it gives. Cost of Ninja and SSD is not that much different from 2 x decent size CFExpress cards. In it's simplest configuration, you can run a Ninja on the hot shoe with a small tilty / flippy mount and a cable. It doesn't have to add that much extra bulk - but that configuration may not work for other people. It's simply about determining what will work for each individual.
 
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marathonman

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Aug 29, 2016
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I love how this is a big story - pretty big breakthrough if you ask me - and yet still no article from Andrew Reid from EOSHD properly covering it as of 1:23pm today. Just shows me how skewed his reporting his to just reporting on negatives and trashing Canon.
Thankfully I don't pay attention to that guy. So many other people out there with a positive outlook on life and with actual talent. Who needs that kind of negativity on a daily basis?
 
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skp

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As a hybrid shooter I already own a Ninja and even before the overheating concerns came up I was planning to mostly use the Ninja for most shooting when I eventually get my R5 just because of the fact that h.265 is so hard to edit, Also the Ninja gets around the 29:59 limit for long takes when shooting events.

So from my perspective, this news is great. The only downside is that I won't have a redundant backup recording if I take the memory cards out. If I can keep the SD card in and record 4kHQ/24fps to both the SD card and Ninja then I'm all set. All I have to do is keep a CF Express in my bag for the rare occasional slow motion b-roll shot at 120fps. (I don't really ever see myself using 8K on a regular basis).
 
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It would seem there should be a way in software (new menu item) to disable any use of installed memory cards that could accomplish the same outcome without having to physically remove the cards?
Then what’s the difference if they’re disabled anyways, why not just take them out. ? I don’t follow the logic for a need to leave them in but disable them. Am I’m not understanding something? I don’t shoot video so I’m not knowledgeable about the workflow.
 
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BeenThere

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Then what’s the difference if they’re disabled anyways, why not just take them out. ? I don’t follow the logic for a need to leave them in but disable them. Am I’m not understanding something? I don’t shoot video so I’m not knowledgeable about the workflow.
I would rather leave them in rather than having to find a place for them out of camera. Also more chances to damage cards by handling. YMMV
 
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The math doesn't quite work that way. during cooling there is no additional heat source. However, during operation, you have a heat source and the temperature of that source is unknown, but could be quite high.
Actually, I believe physics works that way. If a thing (a component inside a camera body) can cool down nearly completely within 2h, then it must have a certain thermal conductivity towards a heatsink (environment). With constant heat input, there is just no way it overheats only after 4 hours. If heat buildup takes that long, cooldown will take even longer. So, if the camera overheats after 4 hours, it will not be completely cool after 4 hours either. Still, recording times are fully recovered after only 2h, apparently.
 
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