bikinkawboy Loc: north central Missouri

My new (to me) camera has two card slots, a SD and a CF. I need to get a new bigger card and I was wondering what differences there are between the two besides the obvious external differences.

My windows 7 computer has a SD slot but not one for a CF. I know a patch cord can be used but my experience is that the downloading process really slows down.

Any suggestions from you folks that know? Thanks!

UTMike Loc: South Jordan, UT

I had to purchase a new card reader, but I use Prograde, so download time was not a problem.

CHG_CANON Loc: the Windy City

For EOS cameras, the CF slot is the "primary" slot and the camera is optimized to capture and write the most images onto this card in the shortest period of time. It's also intended to be your video card. One can assume other cameras have a similar bias to their CF slot. You can review your own usage characteristics to determine if this is even important, and whether just using the SD slot is good enough.

burkphoto Loc: High Point, NC

It depends on many factors...

What is the maximum read/write speed of the camera's SD card slot vs. the CF card slot?

What is the camera's interface? USB 2? USB 3.0? USB 3.1 Gen 2?

What is the computer's fastest interface? USB 2? USB 3.0? USB 3.1 Gen 2?

What is the compatibility limit and the speed of the SD slot in the computer? SD?, SDHC?, SDXC UHS I?, SDXC UHS II?

You probably want to use the fastest combination of card and camera available (or affordable).

You probably want to use a cable from camera to computer ONLY if it is faster than using a card reader.

You probably want an external card reader that supports both the fastest SD cards your camera supports, and the fastest CF Cards your camera supports. I doubt a Windows 7 computer has a very capable SD reader in it. Many are incapable of reading SDXC cards.

Longshadow Loc: Audubon, PA, United States

Well, my laptop will take SD and Memory Sticks (MS); our desktop will take SD, MS, and CF.
I have a bunch of SD cards, like 12, for my primary camera and maybe six MS for my secondary camera, an old Sony bridge. I have ONE CF card, not sure how I came about it anymore, it's old. I use it for our digital picture frame only.

If I bought a camera that had SD/CF slots I would only use the SD slot. I'm not going to buy another set of cards.
Possibly the camera manufacturer utilized the dual type to accommodate people that had either SD or CF so they didn't have to go buy all new cards. Nice selling point, I can use what I have.

If they intended people to use the second slot as backup, why use a different physical format?, which would require people to buy a new set of cards to utilize the second slot. Wouldn't it be simpler to just use the same physical device type for both slots?

Or do they want to help sell the "other" format.

As for speed, I don't worry about that. I just use the cards.
Cards keep getting faster anyway, but the speed limit is determined by how fast the camera can write to them. Using cards that are capable of 3x the camera's transfer speed won't gain you anything. Except the neat feeling knowing you have fast cards.

TriX Loc: Raleigh, NC

I will just add that if you’re unfamiliar with CF cards, their socket has pins unlike an SD card. You need to be VERY careful when inserting a CF card making sure it’s correctly oriented and insert gently and slowly. If it doesn’t slide in easily, DON’T force it. Some card chides in cameras have a fair amount of “slop” in the rails, and if you get the card misaligned and bend a pin (happens regularly), you’re in for an expensive repair depending on what pin you bend and if it can be straightened without breaking. The net-net is be be careful! (It’s typically a $300-400 mistake).

bikinkawboy Loc: north central Missouri

Thanks so much for the cf card warnings! I’ll have to read the manual to figure out what burkphoto was saying. Same language my computer programming son uses that I have no idea what he’s saying.

User ID

Details of the "CF problem" are already discussed above (acoarst many replies will pile on regardless) but the bottom line is that pin-type CF cards were superceded for good reason.

The CF cards pin array mimics an internal computer drive connector that was never intended to be routinely plugged in and unplugged. There were actually stone age (mechanical) micro hard drives that fit into a cameras CF slot.

All that historical background is just to emphasize how ill-suited CF really is for camera cards :-(

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I have one CF-plus-SD SLR. Fortunately for me, that rather specialized camera replaces my 4x5 gear, so speed is not an issue. I rely on the SD slot. If your needs are very different than mine, then you are somewhat at risk of the "CF problem".

FWIW I also have a CF single slot SLR thaz been unused for years, replaced by a single slot SD camera. IOW I shun CF as best I can, and Im verrrry careful when I must plug one in. Theyre excellent cards if you can be flawlessly careful.

Longshadow Loc: Audubon, PA, United States

burkphoto Loc: High Point, NC

These days, some cutting edge digital cameras use both SDXC UHS II V90 SD Cards, AND CF Express Cards, Type B, which are designed for extremely high data rates required for high end video recording.

The Lumix GH6 can record some outrageously detailed video in 4:3 aspect ratio 5.7K "open gate format". (Open gate means the entire sensor is used. Either you are using an anamorphic lens with post-production "de-squeeze," or cropping standard 4:3 video to 4k or DCI 4K or 9:16 "cell phone video" in post-production.) One of the video modes runs at 1.9 GIGABITS per second, and several require 800 Mbps, well above the capabilities of the fastest SDXC UHS II cards.

For still photography, CF Express B cards are expensive overkill.

Longshadow Loc: Audubon, PA, United States

Yea, if I did do video, which I have done on rare occasion, it would be within the constraints of my cameras.
I'm on the antediluvian edge, my cameras are 12 and 16 years old.

therwol Loc: USA

My Nikon D810 has a slot for SD and another for CF. I have never bothered with the CF slot. If I were duplicating my images on two cards or shooting RAW+JPEG on two different cards, I might consider buying a CF card, but I don't do that. No need for me.

Longshadow Loc: Audubon, PA, United States

All my shots, RAW+JPEG, would go on one card. That way I can transfer everything from one card.

But I suppose if a camera had four card slots, someone somewhere would use one card for scenics, one for portraits, one for macro, one for ...

I like one card, it keeps things simple.

burkphoto Loc: High Point, NC

Typical dual slot scenarios:

> Same files to both, one held as backup until successful download of the other
> Stills to one, video to the other
> Raw to one, JPEG to the other
> Fill up one, automatically switch to the other (during video recording)

Cameras that do the last one on that list allow hot-swapping full cards for empty ones while recording.

Professionals benefit the most from dual slots. Card failure is rare, but you cannot re-photograph a wedding or a sporting event or a breaking news scene. There is also something to be said for dual slots if you're on an expensive photo safari or once in a lifetime vacation to some exotic place.

Longshadow Loc: Audubon, PA, United States

I am atypical. (And not in business.)
Not caring what others do. I do what meets my needs.
Yes, card failure is rare. I've had one in ten years, and that was the added (external) memory car in my phone that was NOT a Sandisk card.

My cameras have one card slot, oh well.
We went to Iceland for a week. One camera, one card slot, a few cards, two batteries.