SD Memory?

[kevin44]

I just got a A700 and wanted to know what speed memory card I should be buying. I see all different speeds. Also does anyone know what the largest movies clip I can shoot?

[Jon]

My A620 has a hard and fast 1 GB limit; I doubt the A700 is much more. But for that it requires a fast card. I have SanDisk Ultras for my primary cards. If I run altogehter out, I have a regular SanDisk 1 GB to fall back on, but I don't expect it'll let me do as much.

[kevin44]

Jon- I have contacted Canon and they were not sure what speed to use. They weren't sure on the movie clip size either.

[DavidW]

Soemoen asked me about choosing SD memory for an S3 IS recently, and what follows this paragraph is pretty much the reply I sent via PM. There are some compatibility issues with 2GB cards, as the SD standard only originally allowed for 1GB cards until a way was found to extend it to 2GB. To be standards compliant, 4GB cards require a switch to SD HC - for more on that see this thread (http://photography-on-the.net/forum/showthread.php?t=197503).


There are far more brands of SD cards than manufacturers. Most of the brands bulk buy from a manufacturer, then label and package their cards. In other words, it's something of a gamble as to what you get with most brands. You may read lots of glowing reviews of a particular brand, which are actually about a completely different design of card to the one on shop shelves today.

The three original companies in the SecureDigital Association are Sandisk, Panasonic and Toshiba. For a while, they were the only manufacturers of SD cards, but other companies came along, including various Far Eastern outfits producing cards of sometimes dubious compatibility and performance.

In the early days, everyone wanted Panasonic made cards, as they performed better than Toshiba made ones, and Sandisk tended to trail behind the Japanese companies.

Outside Japan, it's hard to get Panasonic and Toshiba cards - I haven't seen them sold under their brands for some time. Those companies that buy cards in bulk won't buy from these manufacturers as they're amongst the most expensive and there's plenty of cheaper alternatives available these days. That said, there's also been other perfectly decent designs come along from companies other than Panasonic, Toshiba and Sandisk.


What it boils down to these days in my mind are the big two for flash cards - Sandisk and Lexar. Lexar used to rebadge bought in SD cards (I've got a couple of early Lexar cards that are rebadged Toshiba), but they switched to making their own designs some time ago.

All the SD cards I've bought recently are Lexar, though I see no bar to buying Sandisk SD cards. The cards that I'm using in the Canon compacts in my family are all of Panasonic manufacture, because the larger cards I bought most recently are used in my Pocket PCs.


I wouldn't worry too much about the "times" ratings - they tend to be measured in units called "fibs" (if you don't get the British idiom, a fib is a small lie). 150x, if you take the usual CD derived definition that 1x - 150KB per second, is 22.5MB per second. Note that Sandisk and Lexar don't have SD cards that fast. I would think it most likely to be marketing bluster.

What matters most, especially if you're not that bothered about movie mode, is a reliable card - which is why I'm so against the 4GB non-compliant cards. Is the apparent convenience of fewer card swaps worth the risk of losing all that precious data, or accidentally putting the card into a card reader where it won't work? There's a strong argument for two smaller cards than one big one, not least in case you leave one at home by accident.


I don't use the movie mode on my compacts. Accordingly, our family Ixus 700 (Powershot SD 500) has a 512MB SD card, and my EOS 20D has a 2GB CompactFlash card in it (that's because I tend to shoot RAW on the 20D, which means the images are around 8MB each).


I'd tend to go for mid range for SD cards - Sandisk Ultra II, or Lexar Platinum II 60x. If you care passionately about movie performance (though you may well be fine with the mid range cards for movies), or you can find a decent price, you may be better served stepping up to the premium cards (Sandisk Extreme III or Lexar Professional 133x).

If you're interested in Sandisk Ultra II, there is an Ultra II Plus variant, with built in USB, but it makes the card physically weaker and the 2GB variant is not shipping yet.

Sandisk Ultra II SD is a minimum of 9MB write speed (60x), and Extreme III SD is a minimum of 20MB write speed (133x) if that helps any. Sandisk throw in a fairly well regarded recovery program with an Extreme III card, which may be worth having just in case.


My understanding is that the highest speed movie mode on a S2 IS / S3 IS writes a 1GB clip in around 7 minutes. That works out at around 2.5MB/second - as you can see, Sandisk Ultra II / Lexar Platinum 60x should be more than able to keep up with that.

I doubt that the Sandisk Extreme III / Lexar Professional 133x cards will be any faster in the camera - most of the Canon DSLRs top out at around 7MB/second, and I doubt any of the current compacts will be faster - though you will be able to take advantage of the faster speeds with some fast card readers on your computer.


Though I realise it's of only academic interest as you're considering a compact, I only buy Sandisk for CompactFlash. There have been problems with Lexar CompactFlash cards in Canon DSLRs in the past, and I'd rather steer clear.



David

[Jon]

I can attest that the A620 can get up to 9 min. on a 2 GB SanDisk Ultra II. I've done it - 9 min. 24 sec. hit the 1 GB limit, which was documented either in the Canon USA website specs for the A620 or in the manual (prob. the Advanced Users version).

[kevin44]

Thanks David and Jon. I doubt I will be using the movie mode much, but you never know when you might need it.

[nutsnbolts]

Not to bring up an old thread but this was actually helpful.

I just purchased a G9 and I have been walking around using an old 512 MB card that I had for one of my really really really, did I say really, really old digital camera. I don't even know the speed of the SD card. Nevertheless, I placed 2 x Extreme III 2GB cards along with the G9 but apparently it has been 3 weeks now and still no Sandisk Extreme III 2gb cards in my hand. Apparently it's been backordered and don't expect to ship sometime in December!!!

Anyway, I see that they have a 2GB Lexar Platinum II 60x available and wondered whether this was going to be good enough. If this posts holds any weight, it should according to you all. So let's see how this pans out. Man! I feel like I'm running with crutches!