Understanding Overheating in the Canon EOS R5

First, here are the official overheating numbers from the Canon EOS R5 (Amazon, B&H):

Resolution	Approx. Shooting time at 23°C/73°F
8K all formats	20 minutes
4K 120p	7 minutes and 30 seconds camera limit. You can shoot again after 7 minutes 30 seconds. Total: 15 minutes
4K 60p Full frame	29 minute 59 second camera limit. You can shoot again after 5 minutes. Total: 35 minutes
4K 60p APS-C Crop	25 minutes
4K HQ (8K downsampled)	30 minutes
4K Everything Else	Not limited by heat. 29 minute 59 second limit anyway.
1080p	Not limited by heat. 29 minute 59 second limit anyway.

And here are the official recover times:

Format	Waiting period	Max. recording time after waiting period
8K RAW	10 minutes	3 minutes
8K MP4	20 minutes	8 minutes
4K 60p	10 minutes	10 minutes

Now let’s make sense of each.

Check out my comprehensive real world review of the Canon EOS R5:

https://website-39341349.tnb.awf.mybluehost.me/canon-eos-r5-review-good-for-video/

Overheating limits of 8K RAW on the Canon EOS R5

There is a 20 minute overheating limit at 23°C/73°F. You can expect that number to be lower for environments that are greater than this temperature.

This is what you can expect:

You cold start the camera and hit record, it can go on to about 20 minutes until it stops due to overheating.

Once it overheats, you have to wait for a minimum of 10 minutes to shoot again. You can’t operate the camera at all during this period, because overheating affects standby operations as well.

You start the camera again, and you can record a further 3 minutes of 8K RAW before the camera shuts down again.

After this, the fastest you can hope for is 10 minutes of shutdown + 3 minutes of recording thereafter.

If you want longer record times, you must switch off the camera for a longer period. How long?

Can you cool the Canon EOS R5 somehow?

The heat dissipation depends on the difference between the camera temperature when it overheats and the ambient temperature. The lower the ambient temperature the faster it will cool.

This means it will cool faster in 23°C than 35°C. You could theoretically cool it faster by storing the camera in ice packs or cold packs like this one. Or carry a mini refrigerator. I use the word ‘theoretically’ with sarcasm because it’s not practical. You need to freeze the packs first, and I can’t imagine why anyone would go through so much trouble other than to prove a point.

You can’t douse the camera with cold water either. The temperature of the sensor is what’s important. You can’t directly impact the heat on the sensor quickly by throwing water on the camera or submerging it in water.

What kind of video work is the Canon EOS R5 capable off in 8K RAW?

Canon has published official instructions for 8K RAW or MP4:

8K productions where a full-frame mirrorless can be utilized to get unique angles alongside a main camera or additional cropping for 4K productions.

Canon Media Alert

In other words, the Canon EOS R5 (Amazon, B&H) 8K capability is only designed to be used as a B-cam to other cameras, so you can do either:

1. Shoot from tight corners, or shoot on gimbals, drones, etc.
2. Need to crop an 8K image to 4K for special scenes.

It is not intended to be a main camera for any form of 8K.

I know this is disappointing news to a lot of people, because Canon hyped up the 8K without tempering it with this information. Canon did reveal the overheating issue early on, and is clearly stated in their specs, but it was pushed down over the media noise about the R5.

I don’t feel disappointed, because there’s no other camera in this price class that gives you 8K RAW and 4K 120 fps, takes 45 MP, has IBIS and the best AF in its class. Do you understand?

8K RAW is a privilege. Most people can’t afford the high data rates that come with 8K RAW. And most people don’t have the computing power to grade 8K RAW either.

To me, this is a more interesting question:

Can you shoot a short film or feature film with the Canon EOS R5 in 8K RAW?

Let’s say you are a low budget filmmaker shooting a short film. You’ll be happy to know that film magazines popularly either were limited to about 4 minutes (400′ mag) or 10 minutes (1000′ mag).

Even if your scene is a long single take, as long as it’s less than 10-15 minutes (keeping in mind ambient temperatures higher than what’s listed above), you should be okay. For such long takes you’ll probably need about 5 minutes minimum to get back into position and recharge your cast and crew. It’s doable.

What’s troublesome, is if the actors need retakes beyond what’s normal. E.g., if your scene is 5 minutes long. That’s great. But your actor can only go on for 3 takes before shooting stops for a long period of time.

So, this is the key. This formula should tell you if you can actually use a single Canon EOS R5 for short films or feature films:

Shot length (minutes) x number of takes < 15 minutes

Typically directors immediately move to the next take. During this period the camera is on standby, so will overheat.

The other challenge is lighting. The camera needs to be on for the cinematographer and director to frame and light scenes even before the actors turn up. So the camera is already running for a while.

Canon has a workaround for this) (my comments in red):

Before recording starts, the EOS R5 and EOS R6 display an estimate of the recordable time based on the current camera temperature and the set recording mode.

That’s good. At least you know when things are going sideways.

How can you reduce heat buildup in the EOS R5?

Set Overheat Control function to “ON” (default). When the overheat control function is enabled, the movie size and frame rate are automatically changed while the camera is in standby mode to suppress the rise of the internal temperature.

Between recordings, it is recommended to turn off the camera. Possible but not practical all the time.

Position the camera out of direct sunlight. Not practical all the time.

Use an external fan to dissipate heat. Can you sell me one, Canon? Or should I just forget about recording audio?

Canon Media Alert

Note: Those who are hoping for a fan/cooling solution, pay attention to the word used. Canon recommends an ‘external’ fan.

Overheating limits of 8K MP4 ALL-I or IPB on the Canon EOS R5

There is a 20 minute overheating limit at 23°C/73°F. You can expect that number to be lower for environments that are greater than this temperature.

This is what you can expect:

You cold start the camera and hit record, it can go on to about 20 minutes until it stops due to overheating.

Once it overheats, you have to wait for a minimum of 20 minutes to shoot again. You can’t operate the camera at all during this period, because overheating affects standby operations as well.

You start the camera again, and you can record a further 8 minutes of 8K RAW before the camera shuts down again.

After this, the fastest you can hope for is 20 minutes of shutdown + 8 minutes of recording thereafter.

If you want longer record times, you must switch off the camera for a longer period.

In many ways this is worse than 8K RAW, because the camera has the additional step of processing and compressing RAW on top of everything else. I hope I haven’t got this mixed up, because Canon’s official table neglects to mention which 8K is RAW and which is MP4.

Can we use an external recorder for 8K?

No. External recording is limited to 4K 60 fps in 10-bit 4:2:2. No RAW.

Overheating limits of 4K MP4 ALL-I or IPB on the Canon EOS R5

Up to 29.97 fps (30p)

4K HQ mode

If you’re using the 4K HQ (Fine) mode, the camera downsamples 8K for a better 4K image. This is the best 4K image possible on the Canon EOS R5 (Amazon, B&H).

Unfortunately, this mode is limited to 30 minutes (and up to 29.97p). The camera itself places a limitation of 29 minutes and 59 seconds, so assuming at 23°C/73°F you shoot the full length, you’ll need to switch off the camera for a minimum of 10 minutes, and you can shoot for 10 more minutes again before it shuts down again.

I would place the same kind of restrictions on this mode as 8K. Even though you have a little more wiggle room, it’s still not large enough to neglect overheating.

This is what Canon recommends:

When additional resolution is required with a 4K 30p production or for a Full HD workflow where cropping can be desirable with high resolution.

Canon Media Alert

This basically means…nada. Canon has no idea why anyone would use this mode unless they want high-quality 4K. But with that 30 minute recording limit you wonder – why not just shoot 4K normal instead?

If you really were desperate for high-quality 4K you might has well shoot 8K RAW. Both are limited to 29.97p anyway. You get 8K which gives you either oversampling or cropping, and you get RAW.

All other 4K modes

There is no overheating limit. The maximum you can record in one go is 29 minutes and 59 seconds. The recording shuts off.

But, you can record immediately again without delay.

So, those who want to shoot 10-bit 4:2:2 up to 29.97fps continuously can do so, as long as it’s not 4K HQ mode.

Canon recommends:

Full frame 4K: Interviews, longer duration capture such as weddings.

APS-C Crop: Wildlife, Sports, ENG, for 4K or 1080p.

Canon Media Alert

This is interesting. The 4K crop in APS-C is downsampled from 5.1K (not 8K as the 4K HQ mode above). You still get 4K, probably better 4K than full frame, resolution-wise. And, you can use APS-C and Super35mm lenses.

The downside? A lot of wildlife and sports shooters also need 60p. Oops.

50 (50p) and 59.94 fps (60p)

Full frame mode

Here we have a problem. Canon has given us two numbers, seemingly contradictory:

• 4K 60p – 35 minutes total
• 4K 60p – 10 minutes wait = 40 minutes total

Which is correct? I don’t know. Canon uses the phrase ‘Indicates time when recording can be resumed immediately’. This is lost in translation.

The camera has a limit of 30 minutes anyway, so 35 minutes could mean you can shoot for 30 minutes, and another 5 minutes approx. before it overheats. Either way, we can estimate for 30 minutes to be safe.

So, you get 30 minutes, but once the camera overheats, you must wait for a minimum of 10 minutes.

After that you can shoot for about 10 minutes before it shuts down again.

After this, the fastest you can hope for is 10 minutes of shutdown + 10 minutes of recording thereafter.

If you want longer record times, you must switch off the camera for a longer period.

Canon recommends this:

High-frame rate high resolution productions and independent films.

Canon Media Alert

In other words…nada.

You could use this for music videos or slow motion in short films, feature films, etc., where the time period is within your control. But if you’re running and gunning and rolling…rolling…rolling…you’ll be rolling without your Canon EOS R5.

APS-C mode

Again we have a problem. Canon has given us two numbers, seemingly contradictory:

• 4K 60p – 25 minutes total
• 4K 60p – 10 minutes wait = 40 minutes total

Here, too, Canon uses the phrase ‘Indicates time when recording can be resumed immediately’. Who knows what this means?

You get 25 minutes, but once the camera overheats, you must wait for a minimum of 10 minutes.

After that you can shoot for about 10 minutes before it shuts down again.

After this, the fastest you can hope for is 10 minutes of shutdown + 10 minutes of recording thereafter.

If you want longer record times, you must switch off the camera for a longer period.

Canon recommends this:

When additional reach is required with higher frame rates – e.g., wildlife and sports and news gathering within a 4K production or even for tighter Full HD crops in post.

Canon Media Alert

I can’t imagine wildlife or sports shooters being happy with a few minutes of rolling. You never know when you’re going to get the shot. Canon is clutching at straws here.

100 (50p) and 119.88 fps (120p)

This option is only available in full frame mode.

And, it has the worst overheating performance. You get 15 minutes from a cold start.

Canon doesn’t specifically mention cooling times, but you can assume it’s the worse of the two among the 8K options.

This means you must wait for a minimum of 20 minutes and you can shoot for 8 minutes.

After this, the fastest you can hope for is 20 minutes of shutdown + 8 minutes of recording thereafter.

Canon recommends 4K 120 fps for:

Shorter bursts of slow motion.

Canon Media Alert

You nailed it!

Bottom line

In a nutshell, this is what I can make of it:

8K

To be used in controlled productions – short films or feature films that want to maximize image quality with all the benefits of RAW. You will need a backup or another camera just in case it overheats or if your actors are doing too many retakes.

4K 120 fps

To be used for slow motion shots in controlled productions. If you’re doing splash work or anything that is unpredictable, forget it.

4K 60 fps

To be used for slow motion shots in controlled productions, including music videos. You can get through an entire song easily, so this should be doable.

4K 30 fps HQ

To be used for short films or feature films or any controlled production that can’t afford 8K. Can also be used by photographers who just need a little bit of video.

4K 30 fps

To be used for videography (any kind of non-fictional filmmaking).

To be honest, if you’re looking for a video camera for corporate videos, wildlife, weddings, news, journalism, etc., the Canon EOS R5 (Amazon, B&H) is not the camera for you.

The Canon EOS R5 (Amazon, B&H) is for controlled short film or feature film productions, or for photographers who want high quality video, but it’s not a priority.

I hope this is helpful. I hope to have the camera in my hands by the end of July and I’ll run comprehensive tests for my review. Stay tuned.