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.
It will throttled back to write a the slower speed which would be a waste of the CFexpress 1gbs speed. One would only write to the CFexpress with the SD empty. Or else 2 SD cards.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?
Nope, RAW (large file ) to CF Express and JPG (smaller) to SD. RAW is what about 4 times larger than JPG?It will throttled back to write a the slower speed which would be a waste of the CFexpress 1gbs speed. One would only write to the CFexpress with the SD empty. Or else 2 SD cards.
If you are shooting the camera at full speed and want a backup you are out of luck with that SD card slowing things down. We don’t know exactly how bad it’ll limit the camera, but surely it has to in spme way given ho many pixels it is pushing. If on the other hand you are under 10 frames a minute at a wedding or the lik, it won’t effect you in the slightest.Say what?
with two different speed slots in use, the max write speed will be that of the slower card.First off...there is a limitation even in your statement: jpeg to the second card slot. And maybe I am just a jaded former owner of the 5DIII (overall I loved it, but I hated the SD card slot), but I tried jpeg to the SD (UHS I?) card slot but eventually would just turn off that card slot whenever I wanted to truly get all those lightning fast 6 fps.
But, to better respond, I've gone and looked up write speeds to UHS II cards....seems like most of the "fastest" UHS II cards have "up to" 200 to 260 MB/sec write speeds in this article on fastest cards from B&H. A few quick searches on regular (but still Lexar, Sandisk and still UHS II) and I saw 120 MB/sec and 160/sec go by. (EDIT--just looked at my own SD cards that I have "around"...Sandisk Extreme Pros from a couple years go --95 MB/sec...). As I actually shoot RAW to the CF card and jpegs to my SD card in my 5DIV, I just popped out my SD card and looked at a few of the jpeg file size. The low ISO shots were 5-7 MB and the high ISO shots were 13-15 MB. Scale that up to a larger sensor rumored to being in the R5, I am going with 9 MB/sec low end and 21 MB/sec high end (45/30 x 6 and x 14).
So, 12 fps x 9 MB = 108 MB/sec, 21 MB/sec x 12 fps = 252 MB/sec. But then, jump to the 20 fps and you get 180 MB/sec and 420 MB/sec. Bottom line, some of these will require buffering, even with jpegs. This isn't the end of the world. Actually, fast cards paired with even a moderate buffer are still going to be pretty impressive and just fine for most applications.
But, there is a reason the 1DX III has dual CF Express card slots. This is not that.
Question will be. Has Canon chaged its write speed priority? Max write speed to the slower card? Thus one only benefits from the 1GBS write bus if using the CFexpress slot and leaving slot 2 empty
If I purchased a CFexpress card, I would use it and leave the other slot empty else use 2 SDHC cardsBecause with the slower SD installed and the CFexpress also, max speed equals to that of the slower card. One will never get dual CFexpress bus speed. Thus one would have to remove the SD card for that CFexpress bus speed
What downgrade? The R5 won't be the mirrorless equivalent of the 1Dx MkIII! For pictures, the SD UHS-II will be just fine in at least 95% of the cases. I understand that for video at 8K or 4K 60p it will likely not suffice, but personally, I'm happy that it will have both cards format.The 1DxIII has two slots so I would not expect a downgrade.
$197 at Best Buy for 128 gb
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.Sounds great, double CFExpress would be really expensive for users