The Canon EOS R5 will have an SD & CFExpress slot [CR2]

Nov 1, 2012
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People are going to buy a hideously expensive Canon R5 camera and suddenly can't afford the CF express cards for it? The high speed SD UHS-II cards are not dramatically less expensive.

This logic keep irritating me year after year.

Regardless how much the body costs, buying $100 memory card will cost $100.
 
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What's the point in the backup slot if you write raw to only one slot? I always write raw to the both. jpeg is basically useless for me. If I buy R5, I'll be writing raw to the both slots as well.

Well, there are several situations where you will want to write rw in one card and jpeg in other.
For example Photojournalism, sports or weddings. In this type of works I always shoot jpeg in one card and raw in other.

- Photojournalism, sports: First...security, if one card fails you still have another one. Second, in sports or photojournalism you don´t edit the photos, you don´t have time to do it, so you deliver the jpeg file. So jpeg is your primary files. Raws, you save them if you want to edit a photo to make it more artistic for example. Or also for security, if you fail very bad the exposure or the white balance you have the raws to save the day.

- Weddings: Usually I save in one card the raws and in other card jpegs. Why? First security (If raw card fails at least you still have the jpegs to save the day...) and second speed. Sometimes the couple asks you to make a fast presentation in the end of the day and you dont have any time to edit. So you choose some of the best jpegs and put it in the computer. Fast and simple and a happy costumer.

- In wildlife...It depends....sometimes I don´t write in both cards making copies, i do prefer to use both cards writing because I very often fill both cards. If I am on assignment i always carry my laptop so in the dead periods when nothing happen often take of the cards and make direct copies to ssd drives. One at the time..of course cause in wildlife we know how fast and unpredictable are the moments. So, as i make almost instant copies i dont need to make dual raw writing.

But I understand what you are saying, and if you dont make photojournalism, sports or that wedding services, so it´s a good idea to shoot raw to both cards. We never know....;)
 
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jam05

R5, C70
Mar 12, 2019
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Useless is an exaggeration. But having a card that can do 1-4 GB/sec and a card that can do ~300 MB/sec (and I think that is read speed) does introduce issues when you are pushing the limits of the camera. For example, 12 fps x 60 MB (assuming) files = 720 MB/sec. With the CFExpress card, you do not need to buffer that. With the UHS II card, you can not write directly to the card, thus it will need to be buffered. So, this is like having a Ferrari tethered to a Honda. Nothing is wrong with the Honda, other than to get the full performance out of the Ferrari you will need to cut the tether. In doing so, now you are shooting to a single card slot. For most applications this is not an issue and the low cost of the SD card and the fact that SD card readers are common is appreciated.

So, what did we just learn? The R5 will have its burst rate limited by buffer capacity if you want to shoot to both card slots. So starts the ways that we will see the R5 limited compared to the 1DX III. And this is not me whining. This was expected, it is a $3k camera compared to a $6,500 camera.
1gbs per channel write speed for CFexpress
640mbs for gen 2 UHS II Write speed. The camera will write at max speed of the slower slot if used togerher. Has been always the case.
 
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Why purchase a CFexpress card and use it with an SD card in the second slot. You lose the advantage. A waste of money. The CFexpress has only an advantage when using it alone. The write speed is always equal to that of the slower card.

And why should this be the only possible rule? Why couldn't we imagine a scenario in which the SD card is only used when the CFexpress card is full? Or only as a backup, which doesn't have to be as fast as the main card. Or only to store jpeg?

Why limit our imagination to what we believe to be true?
 
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This logic keep irritating me year after year.

Regardless how much the body costs, buying $100 memory card will cost $100.
Yes....But you have to understand that when you buy a camera or a type of camera, you don´t buy "only" the camera! You have to think about the hole ecossistem! If you buy a camera that pushes the limits of writing and ask for better cards you need to accept that you will need better cards. It´s like choosing fullframe or aps-c...If you choose fullframe you know you will need to invest more in lenses. Other wise whats the point of buying a FF?

So..if you are going to buy a camera like the 1dx mkIII or the EOS R5 yes..of course you will need to think about buying new cards And if you are not ready to buy those cards...you might want to think twice about buying those cameras!
Of course if you have already good SD cards and the R5 has a SD slot, you dont need those Cfexpress cards. But tell me, Will you buy the R5 without buying at least one cfexpress card?
 
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jam05

R5, C70
Mar 12, 2019
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1gbs per channel write speed for CFexpress
640mbs for gen 2 UHS II Write speed. The camera will write at max speed of the slower slot if used togerher. Has been always the case.
1gbs per channel write speed for CFexpress
640mbs for gen 2 UHS II Write speed. The camera will write at max speed of the slower slot if used togerher. Has been always the case.
Those that shoot RAW+JPEG to separate cards will not benefit from the CFexpress bus at all. Nada. A wedding photog would not shoot both to the same card. Defeats the purpose of dual cards.
 
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jam05

R5, C70
Mar 12, 2019
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And why should this be the only possible rule? Why couldn't we imagine a scenario in which the SD card is only used when the CFexpress card is full? Or only as a backup, which doesn't have to be as fast as the main card. Or only to store jpeg?

Why limit our imagination to what we believe to be true?
Because it IS the rule. With two cards of different speeds inserted the camera will wite at the speed of the slower card. It has always been this way. With all brands. IF paying for a 1gbs write speed vs the 640mbs SD card one has completely negated that speed by inserting the tortoise like SD card into the second slot.
 
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usern4cr

R5
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Sep 2, 2018
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I don't think this is totally accurate. It sounds like you are assuming raw to both cards, which I don't know why you would do that. If you shoot raw to the fast card and JPEG to the small card it shouldn't impact the buffer significantly should it?
I shoot raw only - period! So I have no use for saving jpgs. So I'll either have to store to 1 card only, or else store to both and hope the slower card doesn't cause a slowdown in shooting stills (which it probably won't for my typical use). Fortunately I don't shoot much video, or else I'd be very disappointed with one much slower card.
 
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jam05

R5, C70
Mar 12, 2019
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I'm glad they have two different slots. The small slot for JPEG backups is nice. Also nice in those times when you want to record raw on the main card, but JPEG on the small card for ability to hand the card immediately to someone with a reader to print/transfer the file. If you had two CFExpress slots then you would have to bring the bulky reader with you or plug to the camera.
you paid for the CFexpress bus/PCIe. It will never be used at its max speed when an SD card is in the second slot. 1gbs CFexpress vs 300 - 640mbs SD card. you will be getting 640mbs tops. Thats tortoise like speed in 2020. Waste of the second slot when using an SD card. May as well use 2 SD cards. Thus the 1dxIII has dual CFexpress slots. Not one of each. Canon is banking on 5D users simply either not using CFexpress cards yet happy paying for it.
 
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usern4cr

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I only write .raw files - period! However, there *IS* a way to write raw to the fast slot at full speed and also use the "background time" (when not writing to the fast slot) to copy the fast slot shots to the slow slot. For stills you will always have periods where you're not shooting and that's plenty of time to copy to the slow slot. For video at highest data rates you will have to wait till you stop shooting video for the copy to commence (which will take awhile). But it will eventually get everything copied (and it will *not* stop you from shooting more to the fast slot since that takes priority over background copies).

If Canon implements this "background store to 2nd slot" then I will be *so* happy since you get raws stored at max speed to 1 slot as well as raws copied to the other slot as time allows!
 
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I shoot raw only - period! So I have no use for saving jpgs. So I'll either have to store to 1 card only, or else store to both and hope the slower card doesn't cause a slowdown in shooting stills (which it probably won't for my typical use). Fortunately I don't shoot much video, or else I'd be very disappointed with one much slower card.

CFExpress is required for faster video.. fast UHS-II cards should be fine in all but the worst of circumstances. Just don't use generation UHS-I cards that you get for $1.99 from china. Somehow sony manages on their flagship to shoot with UHS-II cards and people live to tell the story. You're not going to notice that much of a difference between 640mbs and 1gbs in the real world unless you are button mashing at 20 fps. most people because this will most likely have a slower sensor than the 1DXIII, will find the electronic shutter 20 fps limited, so be using 12 fps for stills because of the mechanical shutter anyways.

Also the faster card is in there most specifically because of video. so i'm not sure how you'd be disappointed with CFE/SD for video.
 
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Ozarker

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Aye, I can imagine the camera runs heavily crippled on a 300 MB/s card vs the 1200MB/s write of the slowest CFExpress card. It’ll likely reduce a lot of the video modes and greatly reduce the frame rate.
Dude, you need a happy pill.
 
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Ozarker

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No it is getting just the right position of the wing. Just the right pose of the fox pouncing on the rabbit. It is nought to do with shooting a movie.
Dang. Luckily for you there’s a CFexpress slot for raw in addition to an SD UHS II for jpegs. Otherwise the world might end. Fox must have really increased hang time since my younger days.
 
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Ozarker

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Totally agree. Compatibility is good but, I would prefer 2 CFExpress card slots, even though I would have to buy them. It is like buying an expensive triathlon bike and putting a cheap water bottle that will increase drag because you don't want to spend the money to buy an aerodynamic water bottle.
Just shave your legs. My gosh, aerodynamic water bottle? Now THAT’S a race winner. They must be really expensive.
 
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Lenscracker

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Good news for still shooters since CFExpress has no value for stills (for a few of these cards one can better buy an RF lens)
Agreed. I do not need CFE to shoot stills most of the time. If I do need 20fps for birding or something I will quickly change to recording only on the CFE card.
 
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slclick

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Dec 17, 2013
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Totally agree. Compatibility is good but, I would prefer 2 CFExpress card slots, even though I would have to buy them. It is like buying an expensive triathlon bike and putting a cheap water bottle that will increase drag because you don't want to spend the money to buy an aerodynamic water bottle.
No it is not.
 
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joestopper

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Feb 4, 2020
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Totally agree. Compatibility is good but, I would prefer 2 CFExpress card slots, even though I would have to buy them. It is like buying an expensive triathlon bike and putting a cheap water bottle that will increase drag because you don't want to spend the money to buy an aerodynamic water bottle.

You have an option: Buy the 1DX III and let us who are less extreme enjoy the R5 which offers options instead of extremes.
 
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