SD or CF?

I did a forum search and didn't find anything which really explained the advantages or disadvantages of either type of recording media, so here's my question:

I've been using SD for both P&S and dSLR now for several years, never had an issue of any kind, but it seems like the higher class of bodies all use the much more expensive CF cards. Why? What is so much better about them that:

1) They would cost 3-4 times as much?

2) That the higher level bodies would all use them instead of SD (or SDHC)?

I'm asking because I have seriously considered upgrading to a 7D, but the cost of CF cards, the change in battery type, and having to start learning controls all over again combine to make me somewhat leery of the change.

Preeb wrote in post #13582654
...I'm asking because I have seriously considered upgrading to a 7D, but the cost of CF cards...make me somewhat leery of the change.

CF cards expensive?
You've never used film have you?

philwillmedia wrote in post #13582679
CF cards expensive?
You've never used film have you?

Of course I have. That has nothing to do with the question I asked though.

Comparing modern media, the CF is actually older technology, and is a bit more complex in it's construction, but I don't know why that would be enough of an advantage to keep it going when SDHC is so much cheaper and seems to perform just about as well from all I've been able to find out.

compact flash writes and reads faster. At least on my MK III which has both card slots.

Preeb wrote in post #13582654
I did a forum search and didn't find anything which really explained the advantages or disadvantages of either type of recording media, so here's my question:

I've been using SD for both P&S and dSLR now for several years, never had an issue of any kind, but it seems like the higher class of bodies all use the much more expensive CF cards. Why? What is so much better about them that:

1) They would cost 3-4 times as much?

2) That the higher level bodies would all use them instead of SD (or SDHC)?

I'm asking because I have seriously considered upgrading to a 7D, but the cost of CF cards, the change in battery type, and having to start learning controls all over again combine to make me somewhat leery of the change.

I am certainly no electrical engineer and can offer no insight into the performance differences between the two formats. I do have a minor point to contest and that is your assertion that compact flash cards are 3-4 times more expensive than secure digital cards. Doing a quick review of prices on the B&H website, for the same specification of capacity and write speed a 16 GB, 30 MB/sec SD card is $26, while a 16 GB 30 MB/sec CF card is $45. I was only comparing SanDisk cards, as they are considered to be one of the better brands by most people, and to do an "apples to apples" comparison. While the compact flash is certainly more, my chainsaw math says the increase is less than double. And the $18 difference isn't an amount that is going to break the bank.

About the only thing I can find "better" in my use of both over the years is a compact flash card is more sturdy, more durable, due to it's larger size. I can also keep better track of them, again because they are bigger.

If you are using a Canon Rebel body already and are happy with it, stick with it. No real need to change. If, however, there are some other things you want to have, like the better controls of the 5D/7D type bodies, then I guess you'll just have to live with buying compact flash cards. The battery should be a non-issue since you get a batter with the camera. Yeah, you can't have spares for all your cameras to be interchangeable, but most modern batteries are of sufficient capacity that unless you are a professional photographer, a single battery will more than suffice for any photographic mission you might undertake.

Just my opinion. Your mileage may vary.

One other point I forgot to put in my previous post. Compact flash is capable, at least as of this point in time, of larger capacity than SD. SanDisk is making a 128 GB card, while the largest SD, at least to my knowledge, is 64 GB.

EDIT: I take back this statement. I just found that Lexar, another top line of memory cards, is making a 128GB SD card. The pace of technology is mind boggling.

First, what do you hope to gain from the "upgrade"? 7D is a fairly pro-oriented camera and you pay a lot extra for features that you may or may not need (only you can say... I'm just posing the question).

Maybe you should look at 60D, which uses the same SD memory as your T1i (though it would require a different battery, but the LP-E6 are large enough and give enough shots per charge that you might only need one spare).

Only recently has SD memory been improved to be as fast and large as CF cards have been for a while. It's now pretty equal. I still hate the tiny little cards... The larger CF cards are easier to handle with gloves on or just in general (and really aren't very large, all things considered). With the little SD cards I have nightmares about losing one or accidentally letting one go through the laundry in a jeans pocket. But this is just personal bias. CF cards have come way, way down in price the last couple years. I just bought a couple Lexar 16GB 400X UDMA for about $100.

There are CF to SDHC adapters, but I've read the writing/reading times does not perform as well as without the adapter. As what Mark said, CF cards price range isn't much of a difference. If I were you, I would upgrade to the 7D, get a CF card that you can afford and upgrade to a Sandisk card like Extreme Pro or Extreme.

MarKap77 wrote in post #13582733
I am certainly no electrical engineer and can offer no insight into the performance differences between the two formats. I do have a minor point to contest and that is your assertion that compact flash cards are 3-4 times more expensive than secure digital cards. Doing a quick review of prices on the B&H website, for the same specification of capacity and write speed a 16 GB, 30 MB/sec SD card is $26, while a 16 GB 30 MB/sec CF card is $45. I was only comparing SanDisk cards, as they are considered to be one of the better brands by most people, and to do an "apples to apples" comparison. While the compact flash is certainly more, my chainsaw math says the increase is less than double. And the $18 difference isn't an amount that is going to break the bank.

About the only thing I can find "better" in my use of both over the years is a compact flash card is more sturdy, more durable, due to it's larger size. I can also keep better track of them, again because they are bigger.

If you are using a Canon Rebel body already and are happy with it, stick with it. No real need to change. If, however, there are some other things you want to have, like the better controls of the 5D/7D type bodies, then I guess you'll just have to live with buying compact flash cards. The battery should be a non-issue since you get a batter with the camera. Yeah, you can't have spares for all your cameras to be interchangeable, but most modern batteries are of sufficient capacity that unless you are a professional photographer, a single battery will more than suffice for any photographic mission you might undertake.

Just my opinion. Your mileage may vary.

I guess I have to confess that I never actually priced them. I was going by a post in another thread where the poster said that the CF card he was looking at was almost $100. That seemed a bit extreme to me.

Just went to B&H to check it out. Good grief! How do you make a selection? I see Delkin 32gb CF cards from as high as $299 down to $84.99, and they are different shapes so it wouldn't seem that they are interchangeable. Delkin's SDHC 32gb is $49.99. Lexar Professional CF 32gb for $73.95 while their SD 32gb card is $44.95. I just get more confused.

amfoto1 wrote in post #13582752
First, what do you hope to gain from the "upgrade"? 7D is a fairly pro-oriented camera and you pay a lot extra for features that you may or may not need (only you can say... I'm just posing the question).

My wife and I are moving to one of the Out Islands in the Bahamas and services will be virtually nonexistent there. I was thinking to upgrade for the added durability of the 7D, and still keep the T1i as a backup. I hadn't made up my mind about anything yet though, and I may just can the idea.

Preeb wrote in post #13582825
...I see Delkin 32gb CF cards from as high as $299 down to $84.99, and they are different shapes so it wouldn't seem that they are interchangeable...

I think not.
CF cards are a standard, so all CF cards are made to the same physical specs otherwise they can't be a CF card.

MT Stringer wrote in post #13582729
compact flash writes and reads faster. At least on my MK III which has both card slots.

I find that not all SD cards are created equal. The class speed ratings seem to vary between brands (tested using H2testw v1.4).
I have 2 Sandisk Ultra II class 2 cards that test at:
Writing speed: 15.4 MByte/s
Reading speed: 16.8 MByte/s
A Lexar 4Gb class 6 that test at:
Writing speed: 10.5 MByte/s
Reading speed: 14.6 MByte/s
2 Duracell class 10 cards (200x) that test at:
Writing speed: 14.2 MByte/s
Reading speed: 17.8 MByte/s
A Lexar micro SD that tests at:
Writing speed: 9.67 MByte/s
Reading speed: 16.7 MByte/s

Just to show the difference, my Lexar 32Gb Professional CF card (& 16Gb) test at:
Writing speed: 19.0 MByte/s
Reading speed: 27.4 MByte/s

Preeb wrote in post #13582825
I guess I have to confess that I never actually priced them. I was going by a post in another thread where the poster said that the CF card he was looking at was almost $100. That seemed a bit extreme to me.

Just went to B&H to check it out. Good grief! How do you make a selection? I see Delkin 32gb CF cards from as high as $299 down to $84.99, and they are different shapes so it wouldn't seem that they are interchangeable. Delkin's SDHC 32gb is $49.99. Lexar Professional CF 32gb for $73.95 while their SD 32gb card is $44.95. I just get more confused.

Well, just like SD cards, CF cards have differing read/write speeds. In SD cards, this is expressed as the "class" of the card. A Class 4 SD card will write data at a slower speed than a Class 6 or a Class 10 card. The same is true of CF cards. While there is a class rating for CF cards, the standard seems to be to just specify the data write speed right on the cards, 15 MB/sec, 30 MB/sec, 60 MB.sec, etc. That is why I used the ones that I did in my previous post to compare costs. I compared an SD card to a CF card that had the same capacity and the same read/write speed specification. Yeah, you can get a 16 GB SD card for small dollars, but then you get what you pay for. Personally, I have not had great success with Delkin brand cards. SanDisk has, without exception, been great in my experience. Lexar is likewise a brand that seems to have a high level of quality.

As to the different shapes, CF cards only come in one shape. Okay, really two, but the older CF I format has virtually died out. They are all CF II cards now. Possibly you were looking at an SD and microSD card.

In any event, if you buy a camera body that requires CF cards, you will have to buy new cards for it. But since you can get good quality cards in the 8-16 GB range for under $50, it really shouldn't bee much of an issue. But if you want to really go nuts, you can get the SanDisk 128 GB Extreme Pro. It's only $879!

MarKap77 wrote in post #13582979
In any event, if you buy a camera body that requires CF cards, you will have to buy new cards for it. But since you can get good quality cards in the 8-16 GB range for under $50, it really shouldn't bee much of an issue. But if you want to really go nuts, you can get the SanDisk 128 GB Extreme Pro. It's only $879!

See this list at B&H

Look at the first 2 16gb cards, then scroll down and look at the first 2 32gb cards. They all say Compact Flash, but are definitely different shapes. The larger ones say they are 103mb/s. The smaller size ones say 66mb/s. Below the CF cards are several SD cards. The difference is obvious.

Preeb wrote in post #13583046
See this list at B&H

Look at the first 2 16gb cards, then scroll down and look at the first 2 32gb cards. They all say Compact Flash, but are definitely different shapes. The larger ones say they are 103mb/s. The smaller size ones say 66mb/s. Below the CF cards are several SD cards. The difference is obvious.

The difference is some of the images have been distorted. Yes, they appear to be different, but the compact flash specification is Xmm wide by Ymm tall by Zmm deep. All compact flash cards comport with these standards.

EDIT: Upon further review, the difference is most likely that the labels are oriented differently between the first and the second cards listed on the page you cite. If you turn the image of the second card 90 degrees, it is the same size as the other images.