Here is the manual for the Canon EOS R3

john1970

EOS R3
CR Pro
Dec 27, 2015
540
692
Northeastern US
The camera buffer is fixed and is separate from the storage medium being written. Its depth does not change but the ability to clear it does depending on how fast the offloading is to the storage medium. The buffer will fill up faster with slow storage medium (SD) and clear faster with faster storage medium (CFX), and thus will appear to have a bigger "depth" with fast storage mediums.

It's probably a typo.
I hope it is a typo as well.
 

HenryL

EOS R3, R5
CR Pro
Apr 1, 2020
355
962
You

You're right but it also says that high data rate video cannot be used with SD cards. The C70 not only supports V90 cards, it requires them at high data rates. The R3 may support V90 cards but their speed advantage is apparently lost. That's what upsets me.
TLDR: I get what you mean now, thanks for clarifying, but that's an apples to oranges comparison.

The C70 is not moving near the amount of data in it's highest modes as the R3 in it's RAW modes. Seems like the same limitations as the R5 when getting in to the RAW video options or high frame rate 4k.

I don't do more than an occasional video clip, so maybe I'm reading the charts wrong, but this makes sense to me. The RAW data rates listed exceed or bump right up against the max sustained write speed of the ProGrade V90 SD cards (all but the lowest settings anyway). The highest rate for the C70 is 410Mbps/51.25MBps, much lower than R3 and well within even the V60 ProGrade cards. Hope I figured that all correctly...my maths is not strong ;)
 

perplex1

EOS M50
Sep 25, 2020
35
14
You

You're right but it also says that high data rate video cannot be used with SD cards. The C70 not only supports V90 cards, it requires them at high data rates. The R3 may support V90 cards but their speed advantage is apparently lost. That's what upsets me.
the c70 doesn't do raw. if it did, it would have the same disclaimer
 

Bob Howland

EOS R
CR Pro
Mar 25, 2012
824
489
TLDR: I get what you mean now, thanks for clarifying, but that's an apples to oranges comparison.

The C70 is not moving near the amount of data in it's highest modes as the R3 in it's RAW modes. Seems like the same limitations as the R5 when getting in to the RAW video options or high frame rate 4k.

I don't do more than an occasional video clip, so maybe I'm reading the charts wrong, but this makes sense to me. The RAW data rates listed exceed or bump right up against the max sustained write speed of the ProGrade V90 SD cards (all but the lowest settings anyway). The highest rate for the C70 is 410Mbps/51.25MBps, much lower than R3 and well within even the V60 ProGrade cards. Hope I figured that all correctly...my maths is not strong ;)
The R5 has the same limitation. Since I don't own an R5, I'd never encountered it before. Sorry folks.
 

Hector1970

EOS R
CR Pro
Mar 22, 2012
1,465
961
Thanks for your sarcastic answer. You must feel very clever.
I thought your post was interesting. The R3 being the only camera released in 2021 Seems actually quite surprising regardless of the supply chain / pandemic situation.
 
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Pixel

EOS RP
CR Pro
Sep 6, 2011
263
165
So I can't find anything about compatibility with EF lenses. Does the R3 not throttle H+ speed with older lenses a la the R5/6?
 

Bob Howland

EOS R
CR Pro
Mar 25, 2012
824
489
what are you trying to point out there?
Nothing of importance. Unlike a still image, the possible video resolutions are known. In the case of the C70, the maximum is 4096 x 2160, so that's the effective resolution of the sensor, 8.85MP. The data processing and storage requirements are probably a lot easier than constructing a 4096 X 2160 video from a 45MP sensor.
 
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john1970

EOS R3
CR Pro
Dec 27, 2015
540
692
Northeastern US
Memory card test in Canon EOS R3

I agree that this is not the most scientific test, but it appears that using solid CF Express cards in the R3 provides a buffer of around 314 shots at 30 fps. Appears that the SD can shoot ~228 photos, but it takes a lot longer to clear the buffer as one would expect.

Canon EOS R3 Memory Card Test

For me I will plan to write RAW files to the CFE slot and JPG/HEIF to SD.
 
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kaihp

EOS R
CR Pro
Mar 19, 2012
1,159
267
The Most Ancient Kingdom of Denmark
Memory card test in Canon EOS R3

I agree that this is not the most scientific test, but it appears that using solid CF Express cards in the R3 provides a buffer of around 314 shots at 30 fps. Appears that the SD can shoot ~228 photos, but it takes a lot longer to clear the buffer as one would expect.

Canon EOS R3 Memory Card Test

For me I will plan to write RAW files to the CFE slot and JPG/HEIF to SD.

It was interesting to see that the buffer depth seemed independent of the speed of the CFe camera. I got a pair of Sony Tough G 128GB cards waiting for that elusive R3, so that's what I'll use.

I plan to shoot RAW (only) to the CFe card. I'm not a pro, so losing images are not on my horizon of concern. In my years of shooting digital, I can't recall losing images due to card failure. To human failure, yes. (but I was able to recover most/all images with the RescuePro SW).
 
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john1970

EOS R3
CR Pro
Dec 27, 2015
540
692
Northeastern US
It was interesting to see that the buffer depth seemed independent of the speed of the CFe camera. I got a pair of Sony Tough G 128GB cards waiting for that elusive R3, so that's what I'll use.

I plan to shoot RAW (only) to the CFe card. I'm not a pro, so losing images are not on my horizon of concern. In my years of shooting digital, I can't recall losing images due to card failure. To human failure, yes. (but I was able to recover most/all images with the RescuePro SW).
I have never lost an image due to card failure either. I typically upload pictures to my SSD at the end of the day and then to two Sandisk Extreme SSD drives (for dual backups). Once images are transferred I reinsert the card into the camera and perform a low level format of the card.
 
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neuroanatomist

I post too Much on Here!!
CR Pro
Jul 21, 2010
27,581
7,386
Memory card test in Canon EOS R3
Thanks for posting!

I have never lost an image due to card failure either. I typically upload pictures to my SSD at the end of the day and then to two Sandisk Extreme SSD drives (for dual backups). Once images are transferred I reinsert the card into the camera and perform a low level format of the card.
I also have never had a card fail, but Murphy's law says it'll be the images of the flying pig that are lost to a card failure and I've always been more comfortable shooting to two cards, which in the case of my 1D X is RAW to both of them.

Given my shooting style (short bursts, I almost never just mash the shutter and keep it there), I suspect I'll be able to write RAW to both CFe and SD (UHS II) without that slowing me down. I bought sets of 64 GB cards (two each), I can't imagine shooting 3000 RAW images in a day which is about what one 64 GB card will hold, even at 30 fps bursts, and if I do I'll have spare cards.

I'm also a firm believer in a backup strategy. The main reason I keep a pair of cards for each slot is that I transfer them to my MB Pro at the end of the day but leave them on the card, until it goes back in. So if I'm shooting on the 'A' cards today, I'll transfer the images then swap in the 'B' cards and format them. Once I shoot with the 'B' cards, I'll put the 'A' cards back in and format them.

My Mac (along with the other 4 Macs in the house) are backed up hourly with Time Machine to my NAS (2 x 10 TB in RAID 1), and I also keep backups on a pair of external HDDs (5 TB each), also an 'A' and a 'B' that I alternate weekly to store one in my desk at work as an offsite backup.