Flash Card Speed

[housewolf]

This should be easy information to find, but it isn't.

Could someonce do a brief tutorial on matching memory card speed to your camera (Canon A85, in my case).

Lexar starts at 4x ,then goes to 12x, and then much higher.

When and why do you choose something higher than the 4X.

Thanks for the help.

[David Metsky]

There are two times flashcard speeds are important; when writing to the card and when reading off the card.

When you take a picture, or a video, the camera writes to the onboard memory cache, and sends it to the flashcard from that. This is because the onboard memory is very fast and secure and the camera needs to get that information out ASAP. Then, it transfers from cache to card at its leisure. This is fine if you take just one shot, but in burst mode or video you are putting a lot of info to the cache and the camera needs to write it out to flashcards before the cache fills up. If the cache fills up the camera will stop taking pictures until it has been flushed.

So, if your memory card is relatively slow, you might only get 20 seconds of video or a dozen shots in burst mode before you camera must pause and write that all out to the flash card. If you card is faster, the cache will get written out before it can fill up, and you can shoot in burst mode or high quality video all you want.

When writing to the computer, the faster card speed can be utilized on USB2.0 connections to download your images much more quickly. With several 1 gig cards, this can be quite timeconsuming so you can save a lot of time here with faster cards.

-dave-

[Newbie]

For the A85, you don't really have to worry about fast cards... What David said is true, but in the case of the A85, the speed is limited to the speed of the camera, which isn't terribly fast for the A85. The other mistake David made, is that Canon cameras(I think all of them), don't wait until the cache is empty to restart taking pictures, it will wait until there is enough space to continue. But do not worry, its fast enough for just about anything you'll need to do. To give you an idea, even a 4x card will enable you to record either a 640x480 video at 10fps for 30secs or 320x240 at 15fps for 180secs. It could maybe(I said maybe) mean that u will be able to take 1 less picture in burst mode, but its usually not dramatic.

So don't worry go for a card which is cheap, I'd recommend maybe 12x Lexar or regular Sandisk card... I say 12x, because the camera is no faster than that, but I am pretty sure its faster than 4x.

[David Metsky]

The other mistake David made, is that Canon cameras(I think all of them), don't wait until the cache is empty to restart taking pictures, it will wait until there is enough space to continue.
Except in video mode, where the video has to stop. In burst mode I think the camera might end up refocusing to set up a new burst mode, effectively starting from scratch, but I'm not sure. I haven't been able to check this on my SD300 since I can't fill up the cache.

-dave-

[EAP]

How do you tell what speed a card is? I've only noticed the MB size.

[wonton]

How do you tell what speed a card is? I've only noticed the MB size.
Most websites will list the specifications for the specific cards. Just do a search online.

[Jredtugboat]

How do you tell what speed a card is? I've only noticed the MB size.

In most cases, the speed is listed on the card and/or packaging itself.

If you do a search at a website (say for example, Newegg or Tigerdirect) the speed of the card is specified as '4x', '12x', etc. on the product listings. I have a Macmall catalog that does the same thing; it's usually no problem.

I bought a 512mb 80x Lexar CF card. It's WAAY faster than my camera, but I bought it as I'm putting together my Future Camera Kit one piece at a time. You know, like fixing up baby's room before it arrives.

Hope this helps.

[gary_hendricks]

For everyday photography, I think the speed of the card is immaterial. I have a SanDisk 512MB card and I don't even know it's speed.

I guess if you're doing professional work, then the speed does matter. Like what David said - for fast writing and reading of images.