Multiple Folders on a Memory Card

Question

Recently when looking at my memory card I noticed that there were multiple folders on the memory card. The file path looked like this:

DCIM > 100D5100 and 101D5100 

The D5100 is the camera I am using but I have seen this behavior on multiple cameras. Why does the camera(s) automatically split the photos into multiple folders?

Note: The photos will go from 1 - 345 for folder 1 then 345 - 700 for folder 2 etc. but I have not seen any patterns that would dictate when a new folder is created.

Asked by Lynda

Answer

This is really a case of read your camera manual. If your camera did not come with a full one, there will be one on a CD. The behavior greatly varies.

Usually cameras use filenames which gives them 4-digit numbering (some use 5 numbers), so you could in theory have 9999 photos in a single folder. However, cameras can break down these images in folders differently. Furthermore, some cameras let you control this using their Setup/Config menus:

• Some DSLRs like the Pentax K-5 aim to keep folders with a set number of images (500 in this case) but they can give you more since they won't break up a bracket.
• Some cameras wont break up bursts, some put them in separate folders.
• Some also have separate folders for images taken in panorama assist mode.
• A few models also break up folders by calendar days and name the folder according to the month and day.
• They can also break things by number of photos shot instead of counting the ones kept. In this case you will have always less than a certain number. Nikon entry-level cameras usually follows this approach with a limit of 499 or 999.
• Finally, some DSLRs, SLDs and a handful of ultra-zoom let folders be created by the user. In this case the folder still contains 3 digit sequence number which increments should the folder itself goes beyond the capacity which the camera likes.

Personally I find this annoying to have to copy from more than one folder but I'm not the one designing these things! What I do is to rename all files sequentially using a small Python script after copying the keepers to my computer.

Answered by Itai

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How can I backup my RAW photos while travelling without Internet access?

Question

This question seems similar to this one, but my needs are different :

• I shoot in RAW exclusively
• I'm looking for a 100% offline solution: while traveling, Internet won't be accessible
• the "laptop" solution is too heavy for me: I'm looking for a lightweight solution
• the simplest, the better: one device to rule them all

EDIT: I'm using good old Compact Flash cards (yes, the bigger ones), so I need a device that can read it. If it can read from other cards, this question might be interesting for more people than myself - that's the whole purpose of the website.

Asked by Jean-Philippe Caruana

Answer

If I'm feeling paranoid about backing up, I use a Nexto DI, which can backup a card directly to its own internal drive.

It reads CF/SD/SDHC, doubles as a USB2/external SATA drive, and is much faster than most of the other similar products I could find. (There are a bunch of similar products available, but this one had the best reviews at the time, about 6 months ago.)

Answered by Matt Bishop

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How often should memory cards be formatted?

Question

Should memory cards in DSLRs be formatted every so often? If so, how often?

I hear that after emptying the card out (transferring images to a computer), that it's a good time to format it to help reduce the chance for error/corruption. Is this true?

I want to point out: Nikon D90 User's Guide by Ken Rockwell

From the site:

Always format your card after you put it in any camera, or if you've connected your camera to a computer.

Formatting your card(s) ensures any folder or file corruption acquired anywhere goes away.

You can shoot without doing this, however constant formatting is good practice and should eliminate ever having any card errors. Be sure you've downloaded and backed up all the files in two different physical locations before formatting.

Asked by sunpech

Answer

I format my card every time I stick it in my camera and start a shoot.

I do this for a couple of reasons.

First, it means every time I start a shoot, I don't accidentally leave the previous shoot on it (and it also means I don't delete it until I start the next shoot, by which time those images are safely on various backup disks; gives me an emergency backup on the card until I'm sure I've got multiple copies elsewhere).

Second, I use multiple camera bodies, and I know people who've had corruption issues with cards formatted by the computer (which I never do) or by one body and used in another because the bodies interact with the card slightly differently. By formatting every time, I know the formatting is what the camera wants and is expecting.

Third, formatting at the start of the shoot will (or should!) catch a card that is starting to fail. At the least, it'll catch some early failure modes in the card -- and in two cases for me so far, it has. So if the card hits an error during format, I know to immediately retire it. I'd rather find out I have a card error at the START of the shoot that midway into it, or worse, when I'm trying to read the images out later.

Note: any time I get a card error, I retire that card. Cards are cheap. Dead cards that eat my only copy of an image is expensive. And formatting a card every time means that every time I shoot gives me a blank slate in a known state that hasn't reported an error. Which means many fewer potential problems later. And FWIW, I basically never run into corrupted cards, lost images or problems during a shoot or during a post-shoot import.

Even if it means the card will wear out sooner, I don't care. I want reliable cards, not ancient ones. I'll happily replace them rather than try to recover images from them....

Answered by chuqui

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What file system are memory cards formatted with?

Question

Is there an industry standard file system cards are formatted with (when you first get them, and/or after a camera formats them)? Fat32, FAT16?

Asked by Freddy

Answer

They're formatted with FAT16 or FAT32 (FAT32 is required for card sizes >2GB), and have a fairly specific (though simple) directory structure something like this:

ROOT --- DCIM -+- ###ABCDE
               |
               +- ###ABCDE
               |
               ...

### is from 100-999, and need not be consecutive. ABCDE is free text.

This structure won't be recreated if you format on a computer, but an in-camera format will usually construct it (or it will be built as required on a blank card).

There are similar standards for file names, and it's all specced out in detail by the Design Rule for Camera File System, which you can read in full here (PDF):
http://www.jeita.or.jp/cgi-bin/standard_e/pdfpage.cgi?jk_n=51

Answered by ex-ms

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Why would you want to take pictures without a memory card in your camera?

Question

Canon DSLRs have an option to shoot pictures when there is no card installed in the camera. This option is enabled by default, and it got me too many times before I realized it can be disabled in the menu.

I was wondering what is the use of such mode. The only one I could think of is when you shoot tethered. Are there any other cases where it would make sense to shoot without a card?

Answer

The main reason for this option is commercial - it allows the camera to be tried out in a shop and see the result of their test. Without this, you wouldn't be able to properly try out cameras. Normally, cameras allow just a small number of test shots to be stored.

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What is the maximum CF card size for a FujiFilm FinePix S1?

Question

My fiance just got a free FujiFilm FinePix S1. An old camera, I know, but also perfect for helping her learn the basics behind photography.

Anyway, we aren't experts on storage at all. We can see that for SmartMedia cards, the max is 64MB. Does anyone know the maximum for the CompactFlash cards? Does CompactFlash work like that, with the memory limits, the way that SD kind of works? Would a 4GB (or larger) Type I card from BestBuy work? Or does the operating system have a size limit?

Any information at all about this specific camera or CompactFlash in general will be greatly appreciated.

Answer

The file system for the camera (given the era, the cards available at the time and their price) is probably FAT (FAT16). There's no indication anywhere that the camera is capable of using FAT32. If that's the case, you won't be able to use cards bigger than 2GB, and may find that only 1GB is addressable.

While they're not nearly as commonly available as cards weighing in at 4GB and up, you can still find 1GB and 2GB cards at very reasonable prices (under $20). Don't worry about the speed ratings -- all of the currently-available cards will read and write faster than the cards of c. 2000 (except the microdrive, which was really rather snappy).

Unfortunately, Fuji's two non-JPEG formats are TIFF, so you won't be able to get very many shots on a card unless you use JPEG, and there is no RAW format. JPEG Fine should be good enough for most purposes, though, and the bit-depth limitation might actually help to learn about exposure, white balance, etc.

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How can I know what speed card to get for my camera?

Question

Cameras rarely specify exactly what speed cards you should be using in them - I just checked the manual for my DSLR, and all it says is to use an SDHD card, and a "high speed" card should be used for recording video.

On the other hand, there are a number of different rating systems for memory card speed (33x! 150x! Class 2! Class 10!) and price seems increases with speed.

Is there any way to test the maximum write speed the camera is capable of? Are the read/write speeds documented anywhere?

Answer

Camera reviews on dpreview mention writing speeds (example: EOS 550D).

If there's no documentation it should be possible to derive actual camera+card write speed by switching to RAW and shooting in sequence until your buffer fills up (then shooting fps should go down significantly). Then writing_speed = raw_file_size * fps_with_full_buffer.

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If I'm happy with the speed, do I really need a faster class 10 or 30MB/s card for my DSLR?

Question

My camera came with 4GB class 10, 30 MB/sec card. I wanted to upgrade to high capacity memory card but I was skeptical, a lower speed card such as class 10, 20MB/sec will cripple my camera when I use it at its highest setting. I checked reviews online for super fast cards. I found this review quite useful. When I did the same test on my camera, I would notice it would stop in the middle (quite long pauses) and I really did not get the full 4 f/s picture that my camera is capable of.

Recently I went to NYC and used up all the memory of my 4GB card in one day so I got worried, I need a high capacity card esp because I want to shoot in raw. Instead of buying an new fast card first, I tried my 16 GB, class 2, micro SD card from my phone and put it test :)

It could shoot continuously (with no delay) at 2 or 2.2 f/s.This was in RAW format. I was actually very happy with that! I thought it would just totally cripple my camera. I did video test too on High Quality, 25 fps and it came out good, no jerks. So I am really happy that I can use my 16 GB class 2 card in my camera.

My question is, am I missing something? Do we really need a 30MB/sec card for the DSLR? Will the photo and video quality be the same with both the cards?

One thing I noticed with class 2 card is that browsing in camera was slow (noticeably slow), but as long as the camera captures the moments right, I am happy with it. Am I missing anything?

This question is more intended to ward, is it kind of myth that you have to use 30MB/sec card?

Answer

This other question covers how to figure out what speed you really need. But to answer the other part of what you are asking: No, card speed does not affect image quality in any way. The image files are digital, and it's not like analog cassette tapes where the composition of the media can make a difference. The only case image quality could be affected is when the slower speed forces you to choose a lower-quality setting in order to make smaller files. But that's a choice you'd make intentionally.

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How fast must a CF be to save 2560x1920 TIFF?

Question

I have an Olympus E-20P which is 10 years old with a 256MB CompactFlash card.

It won't let me choose 2560x1920 TIFF, so I assume that my CompactFlash isn't fast enough.

Are there any rule of thumbs for what speed is needed to save 2560x1920?

Update

According to the manual:

• RAW, 2560x1920, ~10MB
• TIFF, 2560x1920, ~15MB
• SHQ, 2560x1920, ~3.9MB
• HQ, 2560x1920, ~1.5MB

When the camera is powered on it selects HQ, and even if I choose TIFF, it won't change.

So I suspect that it is my "Sandisk CF SDCFB-256" with 3.6MB/s that is the problem.

Answer

I happened to notice this from the FAQ I referenced in the answer to your last question:

Question: If I purchase a high performance CompactFlash card for my E-10/20N, will it reduce the time writing to the media.

Answer: No, the writing time is controlled by the camera, not by the Media.

In other words, it won't help.

(This mentions the "N" version, but as I understand it the only difference is video out format, NTSC vs. PAL.)

And this review say that this camera can only save TIFF in 2560 × 1920 — so something else is going on.

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Can an Olympus E20P take 8GB flash cards?

Question

I have an Olympus E20P camera that is about 10 years old, and the manual says it supports

3V (3.3V) SmartMedia: 4 MB, 8 MB, 16 MB, 32 MB, 64 MB, 128 MB;

CompactFlash (type I and II) Microdrive (CF + type II standard)

Right now I am using a CompactFlash/Microdrive 256MB, which seems to work.

Does anyone know if a 8GB CompactFlash or SmartMedia will work?

Answer

The E20 FAQ from Olympus says that CompactFlash-interface microdrives up to "1gig" are supported. That doesn't necessarily mean that bigger cards won't work, though — unlike SmartMedia, CF doesn't require device support for larger capacities, since there's a standard interface with "smarts" in the card itself. ("Smartmedia" is an Orwellian misnomer; it's the exact opposite — which is one of the reasons it failed to catch on.)

But, it's also very likely that there are other limits that prevent a card much larger than the expected to work. (For one thing, you may run into a limitation on FAT volume size.) You could chance it — it may work. Or you can get a 1GB card which will almost certaily be no problem.

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Do I really need class 10 or 30MB/s card for my DSLR?

Question

My camera came with 4GB class 10, 30 MB/sec card. I wanted to upgrade to high capacity memory card but I was skeptical, a lower speed card such as class 10, 20MB/sec will cripple my camera when I use it at its highest setting. I checked reviews online for super fast cards. I found this review quite useful. When I did the same test on my camera, I would notice it would stop in the middle (quite long pauses) and I really did not get the full 4 f/s picture that my camera is cable of.

Recently I went to NYC and used up all the memory of my 4GB card in one day so I got worried, I need a high capacity card esp because I want to shoot in raw. Instead of buying an new fast card first, I tried my 16 GB, class 2, micro SD card from my phone and put it test :)

It could shoot continuously (with no delay) at 2 or 2.2 f/s.This was in RAW format. I was actually very happy with that! I though it would just totally cripple my camera. I did video test too on High Quality, 25 fps and it came out good, no jerks. So I am really happy that I can use my 16 GB class 2 card in my camera.

My question is, am I missing something? Do we really need a 30MB/sec card for the DSLR. Will the photo and video quality be the same with both the cards?

One thing I noticed with class 2 card is that browsing in camera was slow (noticeably slow), but as long as the camera captures the moments right, I am happy with it. Am I missing anything.

This question is more intended to ward, is it kind of myth that you have to use 30MB/sec card?

Answer

This other question covers how to figure out what speed you really need. But to answer the other part of what you are asking: No, card speed does not affect image quality in any way. The image files are digital, and it's not like analog cassette tapes where the composition of the media can make a difference. The only case image quality could be affected is when the slower speed force you to choose a lower-quality setting in order to make smaller files. But that's a choice you'd make intentionally.

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What's the fastest memory card that can be used with a Canon S95 (P&S) digital camera?

Question

The S95 can apparently accommodate any of the following: SD/SDHC Memory Card, SDXC Memory Card, MultiMediaCard, MMCplus Card, HC MMCplus Card.

Which one is going to be the fastest? I really want to minimize the time to take photos.

Of those choices, I've only used/heard of Secure Digital, so if I had to just pick one at random it would be one of those. "Class 10" SD sounds like the way to go.

Bonus questions: what's the safest bet as far as...

• working in a standard/off-the-shelf card reader?
• longevity?

Answer

Plain SD cards top out at 2GB; SDHC (Secure Digital High Capacity) gets you between 4GB and 16GB; SDXC (Secure Digital eXtended Capacity) gets you from 32GB to 2TB. In practical terms, you're going to be using SDHC cards most of the time -- under 4GB is kind of limiting, forcing you to carry a spare or two, and anything more than 16GB is too expensive to be practical unless you're dealing with a very-high-resolution camera and recording raw data.

The speed of the card is a separate deal. It's not directly related to the capacity.

As for MMC (MultiMedia Card), it's an obsolete format. The SD family shares the same physical layout and electrical contacts, so most SD card devices can also use MMC if you have old cards lying around.

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Are Toshiba SDHC cards good for Canon DSLR cameras?

Question

I was going through the SDHC cards available in the market and found a really cheap card from a website offering discounted camera and photo gear. I did go through the mostly recommended San Disk SDHC cards, but would you guys suggest me to go for this Toshiba SDHC card? I haven't really come across any reviews about Toshiba memory cards. Any suggestions would greatly be appreciated.

My intentions are to use it for HD videos mostly.

Answer

Toshiba is a reputable company that does put out quality products. At one time they have even had claims to fame for the fastest SD cards(source). If you are looking for the cheapest of the cheap, I do not know why you are necessarily asking this question. They are not a popular brand of memory cards, so you will not find many reviews(if any). If you are concerned with speed and reliability, and not price, I would recommend Sandisk, Transcend, Kingston, or Lexar.

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Why do some professional cameras have dual memory card slots?

Question

I have noticed that some cameras such as the Nikon D300s, Canon EOS 1D Mark IV, or Pentax 645D have dual memory card slots.

What is the purpose of having multiple memory card slots and why would you want them?

Answer

Professional cameras such as the Canon 1D Mark IV have dual memory card slots for a variety of professional use cases. I will break them down into three main groupings:

• Mirroring of the image across multiple cards for redundancy
• Automatic switching to a second card after the first one reaches capacity
• Ability to write different file formats to different memory cards

Speed, Redundancy, and Buffers

A theme across the three groupings can be realized, where you will find speed, redundancy and the cameras use of the buffer all play a role. It comes down to what is the most important aspect of your photography, and where do you place your priorities.

If you consider speed to be your number one goal(which it may be if you chose a high end body that has the dual memory card slot feature) then you may want to choose the ability to write different formats. This will prevent the camera from doubling the data going through it on every shot as in the case of mirroring the image. If redundancy and near 100% image preservation is your highest priority, you likely want to mirror the image to both memory cards. If you are more casual about your redundancy and or speed is not the highest priority, you may choose the convenience of having the camera switch to the second memory card when the first fills up.

Other points to consider

If your camera only uses compact flash cards, it will not currently allow use of an Eye-Fi adapter for wireless transmission of images. If the dual memory card support adds an SD card slot, this may be an additional advantage.

There was a time when some cameras came with dual memory card slots to help consumers switch between competing formats, such as xD, Memory Stick(Sony), Compact Flash, etc. These early implementations were not designed in the same way as today's professional dual memory card slots, they were simply to ease the transition for consumers between formats.

Some manufacturers have additional features specific to them, such as Nikon's ability to write video to one memory type and photos to another, or Canon's ability to accept both Compact Flash Type I and II cards.

Conclusion

Overall the dual memory card slots add professional level options that further enhance the photographic possibilities. If you are interested in the fastest possible speed, data redundancy or work in poor weather conditions - these features will provide enhanced opportunties. They do add an amount of additional size to the camera bodies, but for most professionals using these bodies, the features are welcomed or even necessary.

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What would be the fastest memory card for a D5000 that is worth buying?

Question

I own a D5000 and I wonder what memory card to buy for it. I will keep the kit 4GB and downgrade it to "backup" card probably (I will keep it always on me).

Considering a RAW image (I shoot RAW exclusively) is around 10MB and this card cannot shoot faster than 4 frames/second (it's bottlenecked by the internal buffer memory, RIGHT?! Not the memory card?) then it's safe to assume a 40MB/sec card should suffice.

But I'm not sure. Am I correct?

So what speed should suffice for a memory card put in my D5000?

Answer

Burst mode with RAW format will always be bottle-necked by standard SD-cards. I use a class 10 16GB card in my D5000 and I really don't see a noticeable different in the burst speed once the buffer is full compared to the old class 4 card I had. That's why pro cameras still use compact-flash and have larger buffers, it's much faster.

Edit to clarify SD card classes:

The class number is the minimum write speed in megabytes/second when the data on the card is fragmented. So a class 10 card will always be faster in the worst case than a class 4. The class number has nothing to do with the maximum write speed or the latency of the card however. http://en.wikipedia.org/wiki/Secure_Digital#Speed_Class_Rating

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Is it better to transfer photos by removing the memory card or by directly using a data cable?

Question

I can download the pictures from the camera using the data cable or I can unplug the card and plug into my PC's card reader. Both work and I couldn't notice big differences in speed or reliability.

What's your take on this?

Answer

Reasons to use the memory card:

1. A good card reader will be faster than your camera's data cable (a cheap card reader - not so much)

2. When you use the camera data cable you also use the batteries, I had an old camera that really drained the batteries when using the data connection (a set of batteries lasted a few days of shooting or about 30 minutes of data connection) - I expect most cameras are better but I haven't used the data cable since.

3. For SD cards - most laptops have a built in card readers, lots of printers also have card readers, the USB reader that's always connected to my desktop computer right now cost me about $5 - why bother connecting the data cable when I already have a card reader connected.

4. For CF cards - I've heard (my camera only has an SD card) a good card reader will be so much faster than the camera you'll never ask this question again (a new generation reader from one of the leading memory card brands - not my $5 one).

Reasons to use the camera data cable:

1. If you don't already have a built in card reader it's one less thing to carry

2. You could potentially damage the camera's card slot (but I've used my old high end point and shoot so much the lens fell off and the card slot didn't show any damage - so I don't think this is real).

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How can I recover photo files from a CF memory card with a corrupt filesystem?

Question

I know this is not specifically a photography issue but since many of us with prosumer/professional-level DLSRs use Compact Flash cards, it is bound to happen to others as well.

I have a Sandisk 16GB Ultra card that occasionally had the camera reporting inability to access the card. I had to reinsert the card to continue using it. I was able to read the card and transfer the photo files to my computer drive. Today, the same thing happened again, just that nearing the capacity of the card, it failed one last time and the camera was subsequently unable to read it anymore. Despite reinsertion.

My other CF cards never once exhibited this problem, so it's pretty much isolated to this card.

The card is similarly unrecognisable on my computer CF card reader. I think the filesystem is toast, but I suspect the photo files are still intact. I would like to find ways where I can inspect the raw binary data in the card and hopefully recover the photos?

Answer

There are two utilities from CGSecurity that might help.

• TestDisk - Allows direct access to disk data and file recovery from corrupt partition tables.
• PhotoRec - Specifically targeted at recovering photos by identifying byte patterns in images (& video) files.

Depending on what has caused your card to fail will depend on which of these tools will work best.

You can use TestDisk to do a raw backup of the card first to prevent further damage by using recovery tools incorrectly.

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How do I fixe an unresponsive Canon A510 with an adapted Kingston microSD card?

Question

I have a Canon PowerShot A510 using a Kingston 2GB microSD card with an SD adapter. The SD card worked perfectly until I formatted the card in my Mac. I formatted it with MS-DOS Fat file system. Now, when I turn the camera on with this card, it doesn't recognize it, doesn't specify how many pictures it can take with the current settings, and doesn't respond to any button, mode change, the shutter or even the turn off button.

The only way to turn the camera off is taking the batteries out. When I try my older SD cards of 16 and 256 MB, it works ok. I format the card, the Mac reads it perfectly; when I put it in the camera, it encounters the problem above; after which when I put it back in the Mac and it doesn't recognize it anymore. It seems like the camera tried to format it, but left it in an inconsistent format or state. I then have to format it again on the Mac to use it.

PS: As this is almost unrelated to the art of taking pictures, excuse me if it's off-topic.

Answer

You've got a combination of less-than-ideal practices going on here. In general, anytime you bring a card adapter into the situation you're risking potential trouble. Furthermore, it's always recommended to format memory cards in the camera (rather than on a computer) since although in theory a formatted card is a formatted card, there's always a risk that something might go awry.

Given that the A510 is a 6-year old camera and SD cards are pretty cheap, the easiest solution is likely to just purchase a 2GB SD card.

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What is the function of the MISC folder on my memory card?

Question

In all the Canon cameras that I have/had, after every session a MISC folder was created, besides the normal DCIM folder.

This folder was always empty and the camera didn't bother if I deleted it.

What's the point of this folder?

Answer

Its for non-image data that may be used by the camera when processing, storage for user settings (i.e. 1D series...maybe 5D as well), and from what I've heard, storage of temporary audio streams when recording video. Its kind of a catch-all folder that stores anything that doesn't belong in the DCIM folder, and I think most (if not all) of it is temporary data.

---

Due to curiosity, I searched a little more research about canon folder structure. It seems like there is a fair amount of information that can be stored on a memory card by modern Canon cameras such as the 5D Mark II and 1D/s Mark III series. There is obviously the DCIM folder, however unique to Canon, you may also find a CANONMISC folder within the DCIM folder. This contains canon- and camera-specific information that allows the camera to manage the DCIM folder...such as thumbnail metadata for images saved in the camera-specific or stream-specific folders. Also under the DCIM folder will be camera or stream specific folders, such as xxxEOS1D or xxxCANON, where the xxx is a number (100-999) indicating the current photo stream. Images within each photo stream are numbered from 0001 through 9999.

At the same level as the DCIM folder is the MISC folder. This does indeed contain metadata, temporary files, as well as certain settings. Specifically, the MISC folder contains DPOF, or Digital Print Order Format, settings, used when you print directly from the camera to a printer.

The full Canon folder structure is as follows:

\DCIM
    \xxxEOS1D
    \xxxCANON
        \***YYYY.JPG
        \***YYYY.CR2 (raw photo)
        \***YYYY.MOV (video)
        \***YYYY.THM (thumbnail)
        \***YYYY.WAV (audio)
    \CANONMISC
        (DCIM control metadata)
\MISC
    (DPOF settings)
    (temporary data)

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What's the difference between CF and SD cards?

Question

What's the difference? Why do professional cameras support CF but amateur models don't?

Both are flash based, both support FAT filesystems — what's the difference?

Answer

Fundamentally they are the same thing in a different package but they work differently.

SD cards use their own protocol which was extended to go beyond 2 GB up to 32 GB with the introduction of SDHC (there were a few 4GB SD cards but not very compatible) and then to support up to 2 TB with the introduction of SDXC. The SD to SDHC transition if you remember was particularly painful as it took years for most other devices (Readers, Picture Frames, Card Readers, Laptops, etc) to catch-up.

CF cards use the IDE protocol which can index large volumes by using pseudo head, track, sector coordinates. That they just kept working as capacities grew, although FAT32 support is used above 2 GB. That makes the protocol more stable and extensible although the next revision is CFast (Compact-Fast) which is based on the SATA protocol.

The larger physical size of Compact Flash also gives them an edge in capacity and they still have a lead in terms of maximum speed as well. This has historically been significant but the gap is so narrow now that it is mostly a case of legacy.

In terms of camera grades, there are high-end models which each type of memory. The Pentax 645D Digital Medium-Format camera uses SDXC cards, Canon top-of-the-line models accept both CF and SD. This leaves only Nikon to exclusively use CF cards in their high-end models.

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