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

I'm really curious about what's going on here, but here's my theory. Let me know if this sounds crazy...
Is it possible that something in the firmware is constantly making the DIGIC chip encode a stream of data encoded to H.264, H.265, or the raw file format even while the camera is not recording? In theory this could have been intended to minimize delay when the user pushes the record button, thus sending the data to start writing to the card. Think of the encoded data stream like a hose that is just constantly on, spraying water into the back yard until the user decides to put the hose in a bucket and start filling up the bucket.
My theory is that the removal of the card is a bug that turns the hose off, but that bug could be the firmware fix to the whole problem. In that case, the firmware fix could simply be to change that behavior so that the CPU-intensive encoding work doesn't start until the user hits record. The tradeoff would be that it might take longer to get a recording started.
For context, I know that when I'm using my friend's Sony FS7 on film sets, I press record and have to wait a second or two as the tally light blinks and then goes solid before I can be confident that the recording has started and thus before I can call out "camera speeding." Some consumers/non-professionals who buy the R5 might get upset if they miss a moment because the camera didn't start recording the instant they hit the record button.
It might be the cfexpress chipset is not Canons, and as I and others have mentioned, the device is kept active even if it is not being used. Whether Canon can disable that and grab back some power and this heat, who knows.

Ethernet used to keep full power on the interface, switches etc, until they came up with “green Ethernet” so it’s not unheard of for tech not to be entirely energy conscious.

Encoding into h264/h265 is expensive for compute and thus heat. Plus where would it store it? Perhaps In a hidden file on the drive? Then you would get people complaining about storage reporting incorrect free space. I don’t think it is like smartphones, always processing in a buffer once you launch the phone app. But hey it’s all conjecture!

I think it is the device is active when inserted even if it is not used. Whether that is under Canon’s control or the chip which controls the cfexpress etc I don’t know. Ditto whether firmware can change that habit.

That the sd Cards don’t generate as much heat may be simply that you’re not pushing data as fast.
 
  • Like
Reactions: 1 user
Upvote 0
I had a situation where I filmed LQ 4k 30p for about 2 hours straight, in those two hours after about an hour I got locked out of all the HQ modes, and got the overheating warning when I switch to them. But an interesting thing happened. When I switched my battery after 2 hours it instantly gave me 20 minutes of 8k and 7 minuts of 4k120, althought 10 minutes before when I tried to use those modes while the first battery was in I could not do any filming in those modes. After 20 minutes of 8k it heated again I continued filming with the second battery in LQ 4K until it drain (it was an older battery so it lasted about an hour of footage) I tried to replicate the same thing with a third battery and I could not do it.
It seams that with the first changing of the batteries I trigger some bug or sort of a bug that managed to resetet the cameras heat control which definitely suggest that there is room in software for improvement.
 
Last edited:
Upvote 0

domo_p1000

EOS-1D X MkIII | EOS-1D X MkII
CR Pro
Aug 22, 2013
56
67
It seems plausible that firmware could be part of the problem - at least it is possible that a future firmware u/g might help overcome the overheating problem. It would be interesting to see more testing that helps to isolate components that most impact the phenonium.

Perhaps testing the difference between changes in the camera's setup: is temperature equally limiting when filming in PAL and NTSC, for example. Such a subtle change ought to make little or no difference to the overheating characteristics, but if there is a notable difference, it would point more towards a software/firmware problem rather than a hardware problem.
 
  • Like
Reactions: 1 user
Upvote 0
I had a situation where I filmed LQ 4k 30p for about 2 hours straight, in those two hours after about an hour I got locked out of all the HQ modes, and got the overheating warning when I switch to them. But an interesting thing happened. When I switched my battery after 2 hours it instantly gave me 20 minutes of 8k and 7 minuts of 4k120, althought 10 minutes before when I tried to use those modes while the first battery was in I could not do any filming in those modes. After 20 minutes of 8k it heated again I continued filming with the second battery in LQ 4K until it drain (it was an older battery so it lasted about an hour of footage) I tried to replicate the same thing with a third battery and I could not do it.
It seams that with the first changing of the batteries I trigger some bug or sort of a bug that managed to resetet the cameras heat control which definitely suggest that there is room in software for improvement.
Really interesting, thanks for sharing. If you get chance to replicate and reproduce that would be even more awesome
 
  • Like
Reactions: 1 user
Upvote 0
Thanks for the practical info from someone who uses it.

When you use the atomos, or any HDMI out on a Canon, does it switch off the evf and back display, ie you have to use the atomos to monitor what you’re recording?

Im not sure with the R5 as I don’t shoot Canon right now, but Sony has a few quirks.

Only the A6600/r4/a9/a9ii can record internally while outputting over HDMI. Older Sony cameras turn off the rear lcd once the rec button is pressed. Also, in 4K, recording internally with HDMI disables Face AF and Eye AF. This is fixed on the A7sIII as tested by Philip Bloom most likely due to the new processor. I think these cameras all have relatively limited processing power. Maybe the R5 is better, but I haven’t seen any tests yet.
 
  • Like
Reactions: 1 user
Upvote 0
Im not sure with the R5 as I don’t shoot Canon right now, but Sony has a few quirks.

Only the A6600/r4/a9/a9ii can record internally while outputting over HDMI. Older Sony cameras turn off the rear lcd once the rec button is pressed. Also, in 4K, recording internally with HDMI disables Face AF and Eye AF. This is fixed on the A7sIII as tested by Philip Bloom most likely due to the new processor. I think these cameras all have relatively limited processing power. Maybe the R5 is better, but I haven’t seen any tests yet.
Thanks for replying, appreciated. I guess I was trying to figure out if the atomos could act like a recorder and you still use the camera display(s) and thus it could be “hidden” away.

Thanks again.
 
Upvote 0
I found this review https://ihitthebutton.com/canon-eos-r-vs-eos-r5/

It compares the hq vs non hq. Its the last two images. Its saying its a 200% crop! Who views a video at 200% ?
So I saved the first file and cropped out the non hq then viewed them at 50% so that should now be 100%?
They are a bit different but I think if this was a moving video you may find it hard to notice. So then I sharpened the non hq and it looks nearly the same.

I have no idea why removing the card allows more recording. Only thing I can think of its firmware bug or something in the camera generates more heat with a card in the slot? The actual writing to the card is probably not the problem because hq and non hq are the same bitrate 470Mbps. If it is a real heat problem then its probably because its reading a lot more pixels in the encoding for the over sampled version.

I assume line skipping reads half of the pixels from the sensor. Also encoding half of the pixels. Oversampling has to read all of the pixels on the sensor then down sample it. I think doing this may make it read the values from its internal buffer multiple times for each new pixel in the down sampled version. So reading all of the pixels from the sensor probably generates heat and processing twice as many pixels also.

The only other thing I can think of is it can output uncompressed down sampled 4k while staying in the heat limit. But doing that and encoding it and writing it to the card goes over the limit. So by not encoding it and writing it to the card you are saving a lot of processing power/heat. We may not see a solution for internal recording if its really at its limits unless they either make the code more efficient or add more heat sink to the processor. I don't see this working for the sensor but that appears to not be a problem because it is ok with external recording. It looks like the card may play a smaller part because ipb vs all-i does not change the recording times but all-i would stress the card a lot more. But it is possible that the heat from the card is increasing the internal temperature to the point that it can't do over sampling and encoding not going over the limit. So its not that it can't handle writing hq vs non hq to the card just that it makes the internal temperature too high to do it for a long time with over sampling.

Not using all of the pixels (line skipping) is probably what causes the small amount of softness. Its a while since I have looked at any image processing code but I do work as a software developer. So this is just my logic of what could be going on. Not sure if down sampling from 8k to 4k is that expensive on the hardware they use on this type of camera. But once it is down sampled it is now the same as the non hq version in terms of processing to encode it!
 
Last edited:
Upvote 0
I have been doing some test on DJI Inspire 2 with a Cine SSD extention cable.
Maybe it will be possible to get the same with CFExpress and get the card out of the camera body?View attachment 191962
Why do you fly with the ssd external? For faster swapping or have you found a way to load larger SSD's into the canister and fool the I2 into thinking its straight from DJI?

I fly the same thing myself and have never even thought to try what you're doing in that photo
 
Upvote 0
Here is a second video from Vistek where they did the same thing (he didn’t run a torture test but ran it for 2 hours without breaking a sweat)

‪Canon R5 Redux: Deep Testing Overheating, Resolution, and Auto Focus.

This is huge news and hopefully we will see more workarounds like this!!

I don't do a lot of video but the samples in this make me think non hq 4k is probably ok for some people.
Its going to be hard to see the difference its not like 1080 vs 4k difference.
The 60 and 120 fps are probably not going to get used for more than 5 minutes by me. Other people may want to use if for longer and I understand that.
Considering that 4 mins of 120 4k is 64gb that is a lot for me. 60fps ipb looks better for storage at 36 min.

It all looks like it depends on what you want to do with it. To me this camera does more in one box than any other canon I have seen.
It is not really unbiased to compare it with cameras that have fans or a lot less pixels. You can say they do different things but its upto the user to decide what is best for them.
 
  • Like
Reactions: 1 user
Upvote 0
So I've done another test, I took my sandisk CF-express 256gb card filled it full capacity and done a transfer of all the files to my MacBook pro which made it really hot to the tuch also reduced the speed of the transfer after I tried to put something back to it. The most interesting thing was the fact that I could not use any HQ modes on my R5 that was siting since last night on my desk in a shaded room. It seams that definitely the problem with overheating comes from the cf-express card and the communication of the camera with it.
 
  • Like
Reactions: 4 users
Upvote 0

SecureGSM

2 x 5D IV
Feb 26, 2017
2,360
1,231
I have no issue with Canon offering a service centre option (cost $500?) to retrofit with substantial longer video times. Ideally with HDMI2.1. They did it with initial 5Div upgrade to Canon log for $99 (plus shipping). This wasn't a simple firmware upgrade. Canon then baked in the upgrade for new versions and increased the cost from $3500 to $3600. That would be acceptable if the change is only $100. if more then....
Or, Canon could then have 2 models R5 and R5v (see the v = video and also 5 :) )
Or, Canon releases a grip with built-in peltier fan cooling connected to the tripod mount/ base plate for $500. Preferably with 2 batteries or maybe just 1 would give you 2 hours of recording
And/or, Canon could also now announce a partnership with Atomos etc for a compatible video solution with longer times
you see. you would ne
What does a battery grip have to do with it?
An external recorder Inbuilt directly in battery grip.
 
Upvote 0

bergstrom

Photographer
Feb 23, 2015
534
398
This is actually great news, this means I can use my R5 with my atomos for a more serious work.
Although the skipped line 4k is good enough for a lot of work, this is even better. So basically that means all 4k modes except 120p are basically available all the time.
To bad the R6 did not score that great times with the external recorder.
Since R5 is basically the best all-around photo camera today and with this setup I would say it is maybe even the best hybrid camera today it will be a bit large set up for photo/video jobs if you do both at the same time. But If I get two I'm covered.
And if they unlock 120 fps to external recording this is the perfect camera for my needs :D
Thank you Wayne for this info.

there's no portable solution though, is there? The atomos has to be connected to pc? I can't haul my pc around on a trolly while filming at event.
 
Upvote 0

bergstrom

Photographer
Feb 23, 2015
534
398
So I've done another test, I took my sandisk CF-express 256gb card filled it full capacity and done a transfer of all the files to my MacBook pro which made it really hot to the tuch also reduced the speed of the transfer after I tried to put something back to it. The most interesting thing was the fact that I could not use any HQ modes on my R5 that was siting since last night on my desk in a shaded room. It seams that definitely the problem with overheating comes from the cf-express card and the communication of the camera with it.

It's good to talk. Unless you're the CF card and R5.
 
Upvote 0
Jul 26, 2020
188
255
So I've done another test, I took my sandisk CF-express 256gb card filled it full capacity and done a transfer of all the files to my MacBook pro which made it really hot to the tuch also reduced the speed of the transfer after I tried to put something back to it. The most interesting thing was the fact that I could not use any HQ modes on my R5 that was siting since last night on my desk in a shaded room. It seams that definitely the problem with overheating comes from the cf-express card and the communication of the camera with it.
This feels like the web's collective effort to figure this out, just like when Everybody in the world was searching for MH370.
 
  • Like
Reactions: 1 user
Upvote 0
there's no portable solution though, is there? The atomos has to be connected to pc? I can't haul my pc around on a trolly while filming at event.
Atomos can be powered by an Sony NP battery so it is portable, you just need a cage to rig everything. But it goes the same for most of the cinema cameras, without the rigging they are usually not that use-full. There is also an option to set up a rig with V mount battery that will power you camera and the atomos ninja 5.
 
  • Like
Reactions: 1 user
Upvote 0