KarlL

1 minute ago, TheBoogieKnight said:

SMART which is featured in all CFExpress cards as far as I know allows reporting of temperatures.

Ah, that's true! I didn't think about it, but yes it's like almost any memory nowadays.

Thanks!

29 minutes ago, Andrew Reid said:

Why does it need 25 mins in the freezer to get back to baseline temp?

It defies logic.

You heat a metal baking tray to 60C and try putting it in the freezer! It's cold after a minute.

It may be that extreme temp changes do change the artificial timer. It's still fake though. Otherwise the camera would be ready to go again after a couple of mins in the freezer.

I think, the heat does not go down that quick because the camera body functions as an isolation.

I would compare it to putting beer in the freezer:

- if you put just the bottle in, it's frozen within 90 minutes

- if you put it in a plastic box it's taking quite longer.

44 minutes ago, Andrew Reid said:

The problem occurs even with an SD card, which can be used for unlimited 4K recording in other devices without issue.

They don't get very hot (as in 80C+), maybe 50C max.

You can read/write for hours on an SD card in a reader so it isn't about SD card safety regulations.

There are cameras like the S1H that write 6K or 4K at 400Mbit to SD cards. Higher data rates than EOS R5 4K HQ.

They don't get that hot though. I know, I've tried. This is just speculative on your part I'm afraid.

The Cfexpress card I have does get 'a bit warm like a cake'... but not scolding!it really seems to be a c

You can use it in a device that records 4K RAW for hours.

Yes they can.

I agree. They owe us a full and frank explanation.

In my opinion lying to customers is not a good look!

So I hardly think that there's anything about the comparatively low-bitrate 4K HQ 8bit H.264 (with CLOG disabled) on the EOS R5 that causes the Cfexpress card to heat up beyond the safety regulations.

Hi Andrew, thanks for the information you are providing.

I think I may have messed up my point about the memory card. I don't mean that the memory card overheats due to the writing, but because it's close to something hot.

My "idea" was, that
- something in the camera - e.g. the main controller - leads to internals heating up
-- no one cares about temperatures beyond the regulations of surfaces, because it's internal
- this also leads to the memory cards getting hot
-- memory cards can be removed
-- Removal parts apply to the temperature limits defined by safety regulations

From the external forum:

Quote

CFExpress card temperature upon ejection from the camera - Label / Top side: 134f

134F is about 56°C. Safety regulation requires a maximum temperature of 55° C for "prolonged" and 60° C for short periods only.

But this does not explain why it's taking so long to cool down.

44 minutes ago, Andrew Reid said:

Quote

Something I can imagine here is that they cannot directly measure the temperature of the memory cards.

Yes they can

Just out of interest: how do you know?

44 minutes ago, Andrew Reid said:

They owe us a full and frank explanation.

I fully agree with you on this point. Even if they say "The current generation of our DIGIC X can only manage 65°C, because XYZ" it would be OK for me.

But like this I feel fooled and that's not the feeling I should have as the customer.

Very interesting stuff! I'm a hobbyist Canon shooter myself, but I'm still on the EOS 6D since until now I couldn't find anything that really pushes me towards a new camera. The R5/R6 might be the one that actually catch me. However, after reading all of this, I get doubtful.

Besides that I'm an engineer for embedded software / electronics (in automotive) and I would like to share some of my knowledge here.

1. As horshack already pointed out the temperature written in the EXIF might not be the temperature of the main controller, but the one of another chip that's supposed to be a "good"/"reasonable" representation for the inner camera temperature.

2. From our electronics I know that we usually measure 4-5 temperatures from different chips and the differences are quite astonishing sometimes. While the main chip under "heavy duty" might be at around 90°C within a few minutes, peripheral chips show the temperature increase with a (for me) surprisingly high delay of a few minutes. This is partly due to the fact that thermal operations take quite some time, especially if the heat distribution medium is air. This depends on the placing of the chips of course.

3. The issue might not be overheating of the main controller, but of another chip, e.g. of the sensor read out circuit

4. There has been some discussion about maximum temperatures of electronic chips. It is correct that 90°C is still in the comfort zone of most electronic chips. However, you have to take into account that there is a maximum allowed temperature for surfaces is 65°C (Metal) and 85°C (Plastic) due to safety reasons (Source, as an alternative google "safety standard maximum heat surface", Alternative Source). The second source even limits to 55°C for prolonged usage and 60°C for "Short periods only".

I saw some videos in which they managed to shoot 4k HQ continuously for hours, by removing the cards from the camera. If I combine the "safety" stuff with this I get to the conclusion that the issue might be the memory card getting too hot in terms of safety regulations. Here's my scenario: I record for let's say 45 minutes, before my CFexpress card is full. I want to switch cards quickly -> I directly open the card slot and pull out a card that has a temperature of ~80-90°C. This is not acceptable by means of safety.

The only thing that bothers me then is that the temperature should go down much much faster than what's seen here. Especially, if you look at the "tests" that Jordan from dpreview did, in which he removed cards and battery completely. After that the temperature should go down much faster. Something I can imagine here is that they cannot directly measure the temperature of the memory cards. Due to this they use a formula for calculating cool down times. This formula does not take opening the card slot or changing the card into account.

I hope Canon will release detailed information about this. Because even though I'm a stills shooter only, I don't want to be tricked. And I must admit I'm on the edge to switching to Sony, anyway.