EOS R5 Overheating Is Not Artificial ?
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UPDATE: I have changed my thoughts a bit after new tests. See :
www.jodumedia.com/blog/eos-r5-scotch-tape-battery-overheating-trick-but
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The Canon EOS R5 has been a controversial camera. With all the excitement leading up to the release of the EOS R5 based on the drawn out marketing campaign, it was a bit of a disappointment when we first started to hear about some of the limitations around the outstanding video features that we were told about. 8k, 4k120, and 4k60 in an EOS R sized body? It turns out to have been as difficult as we suspected it might be. Based on the information Canon provided and some negative reviews, the high quality and high frame rate video features are severely limited by heat from even just using the camera for photographs and base 4k 24/30p. Many more experienced reviewers have done a great job testing and discussing these limitations (I have put links to some at the bottom of the post). In this post you may find I have provided some interesting additional tidbits. So stick around and read some more to find out.
TLDR
The Canon EOS R5 appears to overheat when reaching an internal temperature of 50 C to 60 C. In all tests the camera consistently overheated when temperatures were recorded in this range. This is probably to protect the image quality produced by the camera’s sensor. Unless the camera’s encoding and storage IO logic is very buggy or the thermal ceilings are raised, no firmware update is going to dramatically improve the overheating issues. A 5-20% improvement may be possible. I found no evidence of artificial overheating!
Tests
In my tests I ran the camera for 5 mins, then quickly stopped the camera, took a picture for the EXIF information, and checked the 4k HQ, 4k 120 and 8k recording time available. The recording time available is according to the camera.
The internal temperature is pulled from the Camera Temperature EXIF property of the JPEGs I took for this purpose. It is true that we don’t know what this specifically represents, but it is what we have and so it is what I used.
Also, clearly there is some minor thermal recovery after I stop the camera to do the time and temperature checks, so this is not a perfect test but it is as close as I could get.
Cold Start 4k HQ Overheat to Recovery
Test Conditions:
*Note in this test I did not check 8k available recording times
Camera: Cold Start
Environment Temperature: 24 C
In the graph below the Y Axis represents both temperature in celsius and available recording time in mins. The X axis represents time to overheat in minutes. So -28 is 28 minutes until the overheating happened and 40 is 40 mins after the overheating occurred.
4K HQ Overheat to Recovery
Summary:
As you can see, the 4k HQ recording lasted 28 minutes before it overheated and it overheated at 58 C. Five mins later the Camera Temperature was already down to 45 C but the available recording times for 4k HQ and 4k 120 were very low. Additionally, you can see the availability curves for recording times do NOT mirror the temperature decrease of the camera. The temperatures decrease at a much faster rate than the availability times. My first reaction was to get frustrated, but I also realized maybe there was some room for improvement here in a firmware update. More in my conclusion section after the tests.
Cold Start 8k Overheat to Recovery
Note I forgot to record the availability times of 8k, 4k HQ, and 4k 120 while the camera heated up. I have seen though that this matches the 4kHQ tests
Test Conditions:
Camera: Cold Start
Environment Temperature: 24 C
In the graph below the Y Axis represents both temperature in celsius and available recording time in mins. The X axis represents time to overheat in minutes. So -20 is 20 minutes until the overheating happened and 40 is 40 mins after the overheating occurred.
8K Overheat to Recovery
Summary:
As you can see the 8k lasted 20 minutes before it overheated and it overheated at 55 C just below what the 4k HQ overheated at. Five mins later the Camera Temperature was already down to 45 C just like in the 4k HQ test. The available recording times for 8k, 4k HQ , and 4k 120 were zero in this case. Additionally, you can see the availability curves for recording times follow the same pattern as the 4k HQ test. The temperatures decrease at a faster rate than the availability times.
Overheat -> Recovery -> Overheat
In this test, I let the camera overheat using 8k, then I turned the camera off and let it recover for various amounts of time. Then I tested to see how long it would take to overheat a second time.
Test Conditions:
Camera: Different temperatures depending how hot it was after recovery time.
Environment Temperature: 24 C
Initial overheat, when I started the tests, was 58 C.
Data:
| Recovery Time (mins) | Camera Reported Record Time | Actual Record Time | Temp Before Test | Temp After Test |
|---|---|---|---|---|
| 5 | 0 | 0 | 46 | - |
| 10 | 4 | 4.5 | 42 | 51 |
| 25 | 5 | 9.5 | 34 | 50 |
Summary:
This is where I got sad. Even though the camera cooled off in a similar way to our 4K HQ and 8K tests above, the overheating temperature when recording after recovery was still in the 50C + range. This despite lasting less time then the first runs from the same temperature. The idea that the recovery times are being artificially limited and not thermally limited do not appear to be true. I will say the camera’s estimated time were off (short), but not enough to cover the cold start times. The overheat temperatures are nearly the same. The Camera Temperature on recovery when compared to the temperature from a cold start does not appear to be an indicator of how fast the temperature will rise to the overheating temperature.
Additional Test Summaries
These are some miscellaneous tests that I performed where I didn’t think it was important to provide detailed data on.
Overheat Recovery while the camera is on but not recording.
I let the camera overheat in 8k mode and then tested to see if it would allow recording in 4k HQ, 4k 120, or 8K after every five mins. The camera was on (including the monitor) but not recording. It was also set to picture mode. After 30 mins I could still not shoot even 1 minute in any of those modes. Pro Tip: Always shut the camera off when not using it!
15 Mins On 5 Mins Off
I recorded 15 mins of 4k HQ then turned the camera off for 5 mins, and repeated until it overheated to see if I could extend the total recording time. I also thought maybe this represented a more real world test. Unfortunately, I was only able to get 29 mins of record time before it overheated with a Camera Temperature of 57 C
Conclusions
It appears, based on these tests, that the EOS R5 tries to keep the Camera Temperature below somewhere between 50 C to 60 C. It does this on every test. I think the test showed that it does it within the range and not at an exact temperature because of testing anomalies and/or potentially how quickly the temperature was rising. It could also be due to how long a specific component has been at a certain temperature.
Despite what seems like temperature headroom after overheating, in practice the tests show the camera is fairly accurate in determining when the camera will hit that 50 C to 60 C range and overheat.
I think Canon wants to keep the temperature in this range for optimal sensor performance. I linked an article at the bottom that talks about the 50C-60C range being the ideal range for a CMOS image sensor like the one in the Canon EOS R5. Increasing the thermal limits may not be what is best for the quality of video and stills. Plus, there could be a point of no return where it can be difficult to keep the camera from severely overheating and damaging other components. For example I noticed my Sony Tough CFExpress card has a thermal limit of 70C.
I was hoping to write that clearly a firmware can drastically improve overheat recovery times. Unfortunately, I am pretty sure that will not be the case based on these tests. I do not think the camera is built in a way where it can dissipate enough heat to handle any more use of the amazing quality 8k, 4k, and 4k 120 video. They may be able to improve it by 5-20% by consistently hitting the 60C temperature. Of course this would assume that would be safe for all the components.
From my tests (and honestly limited experience) only the following could allow for improved recording and recovery times in the EOS R5:
Improve software logic for encoding and writing data to storage (There would have to be an inefficiency issue that is not reported that exists for this to happen)
Increased Thermal Limit > 60 C (Could decrease image quality or damage components)
Lower Bit Rate Modes that put less demand on the Processor, Memory and Storage (Rumored)
Quick Note that Canon’s Bit Rates are still at least twice of the Sony A7sIII. So maybe this would work
Improve power management of components while camera is turned on
Recall the camera to improve hardware’s ability to dissipate heat
My Firmware Prediction
I predict the rumored firmware update will deliver a minor buff in thermal limitation thus marginally increasing recording length and recovery times. But it will be less than a 25% improvement. A future firmware may provide the lower bit rate modes.
I am not sure about a recall. It depends on how Canon really positions this camera in their lineup as opposed to what their marketing department tried to suggest. There is a rumor that a small form factor $3500 cinema camera may be coming out soon that may be what they position as the best video quality at this size and price point.
Of course this is just my opinion. I have zero inside information and I am just an amatuer photographer and filmaker.
Finally, I want to say this article is about overheating. Which is a real issue, but it also makes it sound like I dislike the Canon EOS R5. On the contrary. I love it.
I think the 4k NON HQ in the EOS R5 is a great option and looks plenty good. See the Northrup’s latest video to see how nobody can tell the difference anyway and No Lifes’ video where you can see him sharpen the footage to look 95% as good as 4k HQ.
The truth is, for me as an amatuer, this camera is super overkill anyway. I own it so I want to know what it can do. I do hope they improve the overheating issues, but if they don’t I will still be happy enough with the video features and thrilled with the amazing photography features.
Let me know what you think.
Related Links:
CMOS Sensor Optimal Temperature Post
Gerald Undone EOS R5/R6 Review
Potato Jet Switching to A7sIII
Make 4K Look Like 4KHQ on the Canon EOS R5 | My Mind is BLOWN
The TRUTH about 8K video! CAN YOU EVEN TELL?! (Picture This! Podcast)
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