# Dual CF or Combo memory slots?



## RGomezPhotos (Jan 2, 2014)

I was quite pissed when Canon delivered their 5D MK III with the combo memory card slot setup. But the more and more I think about it. The more it makes sense to me.


Backup. I went with the professional party line that dual CF was necessary in a pro body because you want a backup of your original card. Well, you can do that with a combo setup as well.
Speed. CF cards are faster but that really only comes into play when you fill up your camera's internal buffer first. Even with my ancient but awesome 50D, that's a good 10 - 15 shots before that happens. Even the high-level pro sports shooters have told me they've never filled up their camera's internal buffer.
Redundancy. I'm referring to needing different memory card formats. Yes, that's a bit of a bummer. It's certainly much simpler and easier to carry 4 CF cards that 2 CF an 2 SD. Totally. Or having to need 4 CF and 4 SD cards? Yes. It's a potential cost increase.

So I'm thinking the benefits of expansion and future-proofing with the SD slots to outweigh the negatives. Ideally, two CF slots AND an SD slot in a camera would be perfect in my opinion. But I don't see Canon doing that. With solid performance specs, you could keep that camera for a good deal longer. Hurting sales.

Your take?


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## privatebydesign (Jan 2, 2014)

Dual format works well if you are into Eye-Fi cards, I use them in a 1Ds MkIII sometimes and RAW to CF and jpeg to Eye-Fi works very well.


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## neuroanatomist (Jan 2, 2014)

RGomezPhotos said:


> Speed. CF cards are faster but that really only comes into play when you fill up your camera's internal buffer first.



...and when you have to wait for the buffer to clear. I'm quite glad I have dual CF.


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## privatebydesign (Jan 2, 2014)

neuroanatomist said:


> RGomezPhotos said:
> 
> 
> > Speed. CF cards are faster but that really only comes into play when you fill up your camera's internal buffer first.
> ...



Absolutely agree, I will not have anything in the SD slot unless I need it because it does slow my cameras down noticeably.


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## Mt Spokane Photography (Jan 2, 2014)

I see little or no benefit to the dual format setup. Its mostly takeaway. I'd much rather have Dual CF cards, they are better all around, and I don't have to keep two different card types in inventory.


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## RGomezPhotos (Jan 2, 2014)

Wait till Canon starts using CFast... ;D


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## neuroanatomist (Jan 2, 2014)

Mt Spokane Photography said:


> I see little or no benefit to the dual format setup. Its mostly takeaway. I'd much rather have Dual CF cards, they are better all around, and I don't have to keep two different card types in inventory.



The only benefit I see is for people who shoot RAW + JPG with a need to hand the JPGs off to someone immediately after shooting. SD is a more common format, more devices have integrated SD slots than CF slots. I don't think that's significant benefit for too many people. 

As for keeping different types of cards around, my EOS M, PowerShot S-series (two of them), and camcorder take SD, and my waterproof Olympus P&S takes xD cards.


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## dgatwood (Jan 2, 2014)

RGomezPhotos said:


> Speed. CF cards are faster but that really only comes into play when you fill up your camera's internal buffer first.



CF is only faster because Canon didn't use the latest SD card technology in the 5Dmk3. Otherwise, it would be the other way around.


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## Mt Spokane Photography (Jan 2, 2014)

dgatwood said:


> RGomezPhotos said:
> 
> 
> > Speed. CF cards are faster but that really only comes into play when you fill up your camera's internal buffer first.
> ...


 

Wrong! The speed rating on SD cards is a sucker bet. The rating only applies to a new unused card. Once the card has been written to initially, then it must first erase a block of data before it can write to the block and that drags the speed back to the 10-20 MB/sec write range. 


You can restore a card by doing a low level format, but doing that for a 64mb SD card can take hours.


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## RGF (Jan 2, 2014)

privatebydesign said:


> neuroanatomist said:
> 
> 
> > RGomezPhotos said:
> ...



I keep a card in the SD slot as overflow.

Then again, the 5DM3 is not a particularly fast camera, so dual CF slots is not as necessary as they are on the 1Dx.


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## dgatwood (Jan 2, 2014)

Mt Spokane Photography said:


> dgatwood said:
> 
> 
> > RGomezPhotos said:
> ...



Wrong again. The SD card standard gained a discard command (the SD equivalent of TRIM) way back in eMMC 4.5, which was finalized in June of 2011—nearly a year before the 5Dmk3 was released. Supporting the SD discard command should require nothing more than software-level changes, so if Canon cameras are still showing huge performance hits when you delete photos from eMMC-4.5-compliant SD cards, blame Canon's firmware engineering team for not fully supporting the SD card specification.


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## Schruminator (Jan 2, 2014)

I personally like the set up for previewing and culling images.

I use the SD for low res .jpg's and the CF for the full sized RAW images. This way I can quickly sort through the .jpg's and figure out which pictures are worth going back and editing and which ones can be tossed without having to open up the RAW files (which takes a second or two longer... but multiple that by 300 images and the savings adds up).


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## RGomezPhotos (Jan 2, 2014)

At least with some of the specifications I've seen.. The best performing SD cards tend to be a generation slower than CF cards.

I guess it goes back to how we shoot. Even with the dance events I shoot, I rarely rapid-fire. But that's me and my style.


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## RunAndGun (Jan 2, 2014)

When I need absolute speed on my 5DmkIII, I'll just use my 1000x CF's with nothing in the SD slot. But having dual format slots does come in handy sometimes. I can shoot RAW to CF and JPEG to SD and give the SD card to my GF so she can have the pics without waiting on me to process them(she's not as picky as me and her MBP has a built-in SD slot) and I can also use the SD/JPEG with the camera/usb kit on my iPad to preview images. Or I can shoot RAW to the SD as well and use the SD card in my RMBP and not have to pull out my USB 3 card reader. But I will say, I prefer a more robust card like CF.


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## JohnUSA (Jan 3, 2014)

I like using dual cards as a backup shooting RAW. I second shoot weddings so it's extra insurance for corrupt images/cards, but also at times the main wedding photographer will give me one of his/her cards and at the end of the day I just give the card back. So no need to copy gigs of images to a laptop before I leave or mail my cards back.

I have never run into any buffer issues. Both cards in my 5D3 are Sandisk 64GB.


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## Ripley (Jan 3, 2014)

JohnUSA said:


> ...at times the main wedding photographer will give me one of his/her cards and at the end of the day I just give the card back. So no need to copy gigs of images to a laptop before I leave or mail my cards back.



I hadn't thought of that. I hope to be doing some more second shooting this year, so thank you for posting that!


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## MovingViolations (Jan 3, 2014)

I have dual memory slots in the 1D MII and didn't appreciate it for a long time. Now that the 5D MIII is here in the same format with Eye-Fi available with the firmware update I like it. The pro 16 GB card sending to a cloud storage for safe keeping... I like the idea. I've lost images when cards dies between camera body and computer. Lost my cable years ago so had no option. Even shooters clinging to older 1D * bodies can use the dual slot with Eye-Fi. I got to try it with the 1D MII. I see Live View focusing for large area photographs as a plus using a tablet or laptop to see a bigger image with more detail than the small back can show. And another + is moving forward with the faster cards of both types in the bag already.


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