SD or CF?

The reason the cards look different on that page from B&H is because they are all CF and SDHC cards Delkin make. If you narrow down your search to CF cards only they will all look the same.

Take Care,
Cheers, Patrick

There's a number of key differences between SD cards and CF..

The primary differences:
1. CF cards- all of the contacts are not exposed. As you can see with SD cards, they are exposed.
2. CF cards can be rated for higher read and write speeds than the SD cards.. there are technical reasons why, but from the users viewpoint, - like a class 6 SDHC card (fairly common) is rated at about 6 MB / sec, yet there are a number of CF cards rated at around 90 MB/sec.. Class 10 SDHC cards have diferent ratings from different manufacturers- like the standard is whatever the manufacturer sets...
3. It is my understanding that the CF cards have their own "memory controller" built into each chip, whereas SD cards are a "dumb" technology- lacking their own integrated controller- instead depending upon the device to handle it ( cheaper, but not nearly as fast..)
4. CF cards are more ruggedly constructed.

As someone noted, there are SDHC-to-CF adapters out there, while they can work, they can also be problematic.. Most flash devices- either SDHC and CF - are typically rated "best-case" and not "worst-case"- so a class 6 might not always get 6 MB/sec... Cameras such as the 7D require at least 6mb/sec or better to work well, which is why sometimes there are issues using SDHC to CF adapters with them- because even a class 10 SDHC is not always getting 10mb/sec necessarily..

philwillmedia wrote in post #13582921
I think not.
CF cards are a standard

And that's another difference between CF and SD. CF is a standard, I could take one of my old 8MB CF cards and it'll still work in my 7D. Similarly, my first ever CF card reader will still work with the newest CF cards.

But SD 'standards' keep changing. We've had SD, SDHC and SDXC - and each iteration causes compatibility problems.

wayne.robbins wrote in post #13583611
...2. CF cards can be rated for higher read and write speeds than the SD cards.. there are technical reasons why, but from the users viewpoint, - like a class 6 SDHC card (fairly common) is rated at about 6 MB / sec, yet there are a number of CF cards rated at around 90 MB/sec.. Class 10 SDHC cards have diferent ratings from different manufacturers- like the standard is whatever the manufacturer sets...
3. It is my understanding that the CF cards have their own "memory controller" built into each chip, whereas SD cards are a "dumb" technology- lacking their own integrated controller- instead depending upon the device to handle it ( cheaper, but not nearly as fast..)
4. CF cards are more ruggedly constructed. ....

re: SD card class rating... The class number is the MINIMUM WRITE SPEED certified by the manufacturer, in MB/s. MINIMUM, not maximum. Class 10 is the highest class currently specified by the standard. Therefore, if a manufacturer makes an SD card with a faster write speed than 10 MB/s, it is still a Class 10 card. This is not "whatever the manufacturer sets" ... class 10 still means 10 MB/s write speed minimum.

re: "memory controller" in CF cards is actually an anachronism. CF cards are a derivative if the even older PCMCIA standard, which specified an on-board controller to mimic the even older ATA hard drive controller. It makes the CF cards more expensive and offers no real advantage. The ATA-based CF cards is in need of being updated. Sandisk, Sony and Nikon have proposed a new standard based on SATA. Among other things, this should allow the cards to finally ditch the overly fragile 50 pin connector. "Exposed connectors" or not, the SD connection is physically much more rugged that the 50 pin CF connector. Many SD card contain on-board smarts for such things as flash memory write leveling. They are just not required to have an old ATA hard disk controller on board.

hollis_f wrote in post #13583731
.......But SD 'standards' keep changing. We've had SD, SDHC and SDXC - and each iteration causes compatibility problems.

The change from SD to SDHC to SDXC is a method of extending the capability of the cards. The original SD specification had a size limit (I forget what it was) so the SDHC "workaround" was created to get more capacity in the same physical device. There is some compatibility. An SD card will work in an SDHC capable device, but an SDHC card will not work in a device that was originally built for SD. The same goes for the jump from SDHC to SDXC.

CF is a time tested and proven format. ( also the standard drive interface is nice )

Other formats have come and gone, and CF still reigns.

Ok, Ok, I know today SD is more popular because of all the P&S cameras that everyone from age 2 and up uses.

Canon made a concession to P&S owners in an effort to move them over to DSLR's by putting the SD card in the 60D


When asked if the CF format was on its way out, and noting Canon put SD in the 60D a Canon Rep said this .....

" we ( Canon ) put the SD card in the 60D because we felt the target customer ( p&s user ) for the 60D would already have a few DS cards around. The Compact Flash format is here to stay and will be here for a long time to come. "

Canon did put an SD slot in one of its 1D series bodies but the new 1DX coming out will have two CF card slots.

Interesting discussion.
I clearly fall on the non science side of things......not that I don't like science.
Never for a half of a second, (well up to now) did I think about why one used a different card and why.

My mind, right, wrong or indifferent, concluded CF must be better than SD as more expensive cameras use the CF cards and themselves are more expensive.
Not that something being more expensive automatically makes something better....but in this case.

And considering whether or not to switch based on the cost of CF vs SD and a battery......
A) your interest In photography is not that great OR..............
B) love the science of things and like to know how the inside of that thing works.

hollis_f wrote in post #13583731
And that's another difference between CF and SD. CF is a standard, I could take one of my old 8MB CF cards and it'll still work in my 7D. Similarly, my first ever CF card reader will still work with the newest CF cards.

But SD 'standards' keep changing. We've had SD, SDHC and SDXC - and each iteration causes compatibility problems.

Yup .. CF cards use as standard ATA interface.


I know there was work being done on a new CF card using the SATA interface, but have not followed that endeavor.

You-by-Lou wrote in post #13583939
And considering whether or not to switch based on the cost of CF vs SD and a battery......
A) your interest In photography is not that great OR..............
B) love the science of things and like to know how the inside of that thing works.

or

C) With the advent of the DSLR your computer interests and love of photography were merged.

My interest in photography goes back to before many on this forum were born. I find it interesting to talk to those 'photographers' whose first camera was a DSLR. Yeah there are a few out there, even though Auto-Focus technology is relatively new.

Canon's EOS 10D was my first DSLR and even through my time with the 20D I was still shooting a lot of film and using a scanner to digitize. It probably was not until my 40D that my work was more digital than film.

Even today when I have an important project, out comes the EOS 3 !

wayne.robbins wrote in post #13583611
so a class 6 might not always get 6 MB/sec....

Not true with SD cards. There class is the slowest they will write while the MB/s rating that manufactures put on them is the max best case scenario they will write at. So a class 10 SD card that says 30mb/s will write at the slowest 10MB/s and at fastest 30MB/s

hollis_f wrote in post #13583731
And that's another difference between CF and SD. CF is a standard, I could take one of my old 8MB CF cards and it'll still work in my 7D. Similarly, my first ever CF card reader will still work with the newest CF cards.

But SD 'standards' keep changing. We've had SD, SDHC and SDXC - and each iteration causes compatibility problems.

Using your example, I can take any of my old SD cards and use then in any camera that takes SD, sdhc, or sdxc. However the issue that comes up with SD formate is that you can not use sdxc cards in a 7 year old camera that only takes SD or sdhc cards.

gremlin75 wrote in post #13584036
...Using your example, I can take any of my old SD cards and use then in any camera that takes SD, sdhc, or sdxc. However the issue that comes up with SD formate is that you can not use sdxc cards in a 7 year old camera that only takes SD or sdhc cards.

True, but it avoids the practical issue. Suppose I have a device that only supports SD. Ever try to go into your favorite store these days and buy an SD card? You can still find them, but the huge majority of cards hanging from pegs in your local big box are SDHC. SDXC is still too expensive for mass adoption, but it is coming down. Personally, I do not believe the CF spec writers were more forward thinking than the SD spec writers; they just lucked out that the interface they chose to adopt had a larger address space. For the current application use (mainly digital cameras), the interface has unnecessary complexity. It WILL eventually succumb to the market pressure and tech advancement and there will be a break in the CF card compatibility continuum when SATA is adopted.

Secure Digital type cards have a 9 pin interface rather than a 50 pin interface of the Cf card. This limits them to a 4-bit data transfer bus rather than the 16-bit data transfer bus of CF cards. In principle this makes their maximum possible transfer speed slower, but in practice there is little difference when used with current digital cameras and recently acquired SD cards of Class 6 and up. However, on a practical comparison differences may exist so typically high end cameras are CF or both. This is likely to continue because in 2010 a proposal was put forth by several CF card manufacturers to treat the card as a SATA type drive, as opposed to the current IDE type drive. This would enhance read/write speeds tremendously. The CF card has an internal hard drive controller which increases it cost whereas the controller for the SD card is in camera.

CF cards also can bend the mating pins in the camera body, although this seems to be rare. Many users remove the card when transferring pictures to a PC. Here is a link on the potential bent pin issue. It has clear pictures of what to look for on both the card and in the camera body.

http://www.tomguilmett​e.com/wp/my-bl...age-3#comments

John from PA wrote in post #13584155
Secure Digital type cards have a 9 pin interface rather than a 50 pin interface of the Cf card. This limits them to a 4-bit data transfer bus rather than the 16-bit data transfer bus of CF cards. In principle this makes their maximum possible transfer speed slower, but in practice there is little difference when used with current digital cameras and recently acquired SD cards of Class 6 and up. However, on a practical comparison differences may exist so typically high end cameras are CF or both. This is likely to continue because in 2010 a proposal was put forth by several CF card manufacturers to treat the card as a SATA type drive, as opposed to the current IDE type drive. This would enhance read/write speeds tremendously. ...

And, yet, SATA is only 7 pins!

harcosparky wrote in post #13584004
or

C) With the advent of the DSLR your computer interests and love of photography were merged.

My interest in photography goes back to before many on this forum were born. I find it interesting to talk to those 'photographers' whose first camera was a DSLR. Yeah there are a few out there, even though Auto-Focus technology is relatively new.

Canon's EOS 10D was my first DSLR and even through my time with the 20D I was still shooting a lot of film and using a scanner to digitize. It probably was not until my 40D that my work was more digital than film.

Even today when I have an important project, out comes the EOS 3 !

Very interesting indeed.
I am only a DSLR guy yet I'm 54.
Always loved taking pictures....with that said I had what apparently to me was a traumatic experience when mr deLuca improperly loaded my second roll of film on a trip around manhattan on the circle line whilst in the third grade.
So in my life time I have never loaded a roll of 35mm film.

One ex wife was a photographer in the navy so she always loaded everything up.
A long term relationship was a photo buff and she also was the film handler.....and as to buff......she looked rather good in it
Yet another ex wife was traumatized by a father who only bought film rather than heat so once again

Anyway......have no idea what I am rambling about.....other than DSLR only

John from PA wrote in post #13584155
Secure Digital type cards have a 9 pin interface rather than a 50 pin interface of the Cf card. This limits them to a 4-bit data transfer bus rather than the 16-bit data transfer bus of CF cards. In principle this makes their maximum possible transfer speed slower, but in practice there is little difference when used with current digital cameras and recently acquired SD cards of Class 6 and up. However, on a practical comparison differences may exist so typically high end cameras are CF or both. This is likely to continue because in 2010 a proposal was put forth by several CF card manufacturers to treat the card as a SATA type drive, as opposed to the current IDE type drive. This would enhance read/write speeds tremendously. The CF card has an internal hard drive controller which increases it cost whereas the controller for the SD card is in camera.

CF cards also can bend the mating pins in the camera body, although this seems to be rare. Many users remove the card when transferring pictures to a PC. Here is a link on the potential bent pin issue. It has clear pictures of what to look for on both the card and in the camera body.

http://www.tomguilmett​e.com/wp/my-bl...age-3#comments

Partly correct. SD cards are really a serial communication system, vs CF which is parallel. Hence the pin count differences. The pin count doesn't affect the capacity in a serial system. The capacity limitations are from different sizes of a field in the communication protocol that can limit the capacity of the card. It is sort of similar to 32 vs 64 bit computers and the addressable memory size of 4GB vs many TBs.

The pin counts are similar to PATA drives in the past vs SATA hard drives now.