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This Hack Stops the Canon EOS R5 from Overheating

Keen videographers have been busy finding ways to work around the limitations that Canon has imposed. Grab yourself some sticky tape and a toothpick.

Thanks to teardowns and lots of tinkering, speculation has mounted over recent weeks that Canon’s overheating timer on the brand new EOS R5 is actually set — perhaps arbitrarily — by software, and not by the camera passing a temperature threshold. (Check out this recent article to find out more.)

This short video from J. Marcus shows you his process for fooling the R5 into resetting the overheating timer. When you switch a camera off, it performs an orderly shutdown, and remembers certain data such as aperture, shutter speed — and in the case of the R5, how many minutes are left on the overheating timer. If you can shut down the R5 without giving it chance to remember this data, the overheating timer is then reset when you switch it back on.

Andrew Reid over at achieved something similar a few days ago, preferring a slightly different method that uses a small screw instead of a combination of sticky tape and a broken toothpick. Reid has since reported that he has been able to record 8K video for 50 minutes (three 17-minute-long clips) using this method.

As noted by Marcus, by using a workaround to evade the camera's restrictions, there is a risk that you may damage the R5 by causing it to overheat.

Has Canon has created these limits to err on the side of caution, or is it imposing excessive restrictions in order to cripple the R5 and protect its line of cinema cameras? Be sure to leave your thoughts in the comments below.

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Ryan Mense's picture

Firmware update v1.1.0: Fixed bug causing overheat timer to be reset through removing internal or external batteries.

Felix C's picture

So I was right, this is a hardware issue that no firmware fix will be able to correct. The only thing Canon can do is optimize the algorithm to squeak out some additional time, but the issue will be there until the Mark 2 version comes out. Too many idiots that think they have a BSEE degree from YouTube University.

These idiots have not the slightest clue what damage is occurring. Next you will get tons of complaints that their R5 are failing prematurely. 8K has a data rate four times of 4K, what Canon did was a big thing. If they want a 8K cinema camera, go buy a RED camera then.

Richard Richard's picture

This is why I would be very wary about buying a second hand R5.

Rayann Elzein's picture

Actually that's a very good point. When/if I'll ever be on the market for one, really make sure to buy it from a photographer and not a film maker!

Wilder Berry's picture

It's almost like fstoppers should just rename itself EOSHD and be done with the pretense of caring about creating images and telling stories....

Nick Straub's picture

Someone please explain to me how an internal temperature of 140 degrees F in a camera without any fans isn't the cause for the overheating issue? Constantly ripping out your battery and keeping the camera that hot is only going to confuse the camera to continue working even though it's temp hasn't gone down whatsoever. It's not any way of actually recording 8K because all of the footage is lost. Please quit giving attention to this nonsense.

side note: good thing you mentioned EOSHD otherwise you'd be next on his meme list.

Just me's picture

You means that:
When you put back the battery, it's normal that there is no actual temperature measurement?
A camera that is well known for overheating will not do a temperature measurement at boot prior to accepting a recording?

Nick Straub's picture

No, I am talking during 8K recording the camera gets beyond 140F, which is why it warns of overheating and saves the data and shuts down. People claiming that 140F is normal for inside a camera shouldn't be talking about cameras.

Just me's picture

When you are taking a picture every minute inside a fridge at 4 degree Celsius, after an hour, the camera shut down in 8K video mode telling you it's overheating. Even with not one single frame of video recorded. This is normal?

Nick Straub's picture

When you lay a burning piece of paper in your fridge does it immediately stop burning? Pretty sure I can still have a wood burning fire even when its below freezing outside.

Just me's picture

This is not a hack, cause the recorded clip is not usable. This hack is not from EOSHD and have been publish by others prior to Andrew's experience.

It is not a usable hack in real life.
This is a proof of canon faking the overheat issue or is not reading temperature level at boot.
In both case; this is wrong.

Side note:
Putting this overheat scandal on EOSHD only is quite surprising as the guy did not discover any of these behavior himself. He only followed and copied existing findings.

Rayann Elzein's picture

Next articles on Fstoppers: "I don't understand why the sensor of my R5 melted" and "Canon's a bitch, they won't repair my R5 under guaranty". Oh and also "My R5 doesn't save my 8K clips to the memory card, I lost a whole wedding".

Just me's picture

For sure! When Canon designed the R5 and decided to not check temperature at start worries me quite a lot. (Removing the battery remove the warning when camera is restarting)

Relying on timer more than actual temperature reading is not the way to go.

sam dasso's picture

It is amazing to me that some youtuber (perhaps high school dropout) is teaching Canon engineers how to do thermal control of their cameras. It is common knowledge that temperature over 70C reduces life of any semiconductors. I don't know how temperature is controlled in R5 nor do I care as long as it prevents reduced performance or reduced life of the camera. I'm a Sony shooter and I don't have a dog in this fight , but Canon shooters don't be stupid and don't try to force your expensive camera to do what it wasn't designed to do. I'm retired aerospace heat transfer engineer and have absolutely no doubt that Canon heat transfer engineers know what they are doing.

Wilder Berry's picture

Thank you for your sensible contribution. YouTube is ample evidence, if you ever needed it, of the Dunning–Kruger effect.

Just me's picture

Great, So maybe you can help me understand this graph.
By removing the battery every 15mn, user could record about an hour of 8K footage. This is the temperature from the EXIF file and may be lower than the actual internal temperature. But this is not the exact point.

How come just removing the battery will give again 15 mn of new recording time, with no overheat shut down?
If the camera was not happy with the temperatures, should it just stop recording at one point?
Which kind of engineer design a system that should overheat without temperature check at boot?

Are the sensor not read once during 100 minute, or the Canon design team though the temperature is still fine for the camera to keep recording?

Yes, there are plenty of funny stuff all over YT, but this experiment has been repeated with many user with the same results.

sam dasso's picture

Easy. EXIF reports sensor temperature and being over 60C not only affect performance but is also very unhealthy for sensor life. But problem is that you don't know processor core temperature and how high and dangerous it is. Again, heat transfer engineers at Canon know what they are doing and unlike youtubers they do know critical components temperatures and design safety measures to prevent camera failures. As for designing temperature control software assuming that some idiot will remove backup battery to continue shooting, I can not blame Canon engineers because there is no way to predict what idiot will do. Just like putting cat into microwave oven to dry it out.

Felix C's picture

That is easy. Canon did a poor job in creating a lock. They assumed someone would not do this workaround. If it is not corrected in this current revision, I would assume that in a later version that it will be corrected. If you exceed the design specification for a component, the part will either, fail right away, fail next week, maybe fail in a month, or maybe in a year.

During the process of making the camera, Canon would have installed numerous thermocouples throughout the camera. They would also have done tests at elevated temperatures and reduced temperatures. Since apparently there is an onboard temperature sensor, they know exactly what the temperature delta is for each component on the camera. With this information, they will calculate the MTBF of each component, which is temperature dependent. With this information, they would have given it to the firmware engineers to monitor the temperature to insure that the camera will operate at a acceptable MTBF.

Now by removing this lock, you have not the slightest idea what damage this is causing. Too many wannabe hardware engineers thinking they have a YouTube University BSEE.

Kevin Key's picture

My truck sometimes overheats when I'm towing my trailer up a steep grade on days when the temperature is over 100°. After reading this article, I now realize that I can solve the problem by disconnecting the coolant temperature gauge on my dashboard.

Just me's picture

Except here, nothing is removed.

Just turning on and off the camera.

You have to admit if your truck temperature drop to a fully acceptable level at each time you restarting your engine; you may have discover some way to save us money on air conditioning system

Felix C's picture

Maybe you can get EOSHD and Fstoppers to pay for your blown head gasket.

Just me's picture

Here is a new hack from this Sunday the 6th of September. It do not lose data, do not force you to open the camera, it's simple and easy.
It also clearly shows that all these overheat excuses are completely fabricated and an simple flag setup with a time stamp difference is responsible for bricking your camera, on the recording time and cooling time.