SD Memory Cards

[Tracey]

I am looking into buying a compact camera to complement my DSLR. I want a small camera I can have with me every time I step out of my house, and the DSLR kit is too big to take everywhere.
The camera I am looking at uses SDHC cards, but having no experience with these cards I was wondering what the difference between all the classes is.
Can anyone tell me the difference between a class 4 and a class 6, or even a class 10?  7day shop say they are not backward compatible, what does this mean?
Sorry if they are newbie questions, but my DSLR takes compact flash, so this is my first SD purchase

[Grendel]

well heres a wikki page all about it - still not sure I understand enough to explain
http://en.wikipedia.org/wiki/Secure_Digital#Types_of_cards
there is SD, the basic card, then SDHC (a more up to date version) and SDXC (using a different file system to allow greater capacity) and then an SDIO (thats io not 10) that seems to combine a memory card with an input / output device, so you would need to find out which card types were compatible with the camera you were thinking of, though it seems if it accepts the later cards it should be compatible with the earlier, its just that if it only accepts the SD format it wont be able to see the later formats (thats how it reads to me anyway). then you have the speed of the cards, the SDHC are faster access than the SD which is good as it means the camera saves the file to card quicker.
my fairly old canon A710is runs an 8Gb SDHC card with no problems and thats a few years old now.
Grendel

[Tracey]

Thanks Grendel

So if I have a device that is compatible with SDHC, it doesnt matter which class I get?

[Grendel]

thats how I read it, if you want huge cards then you need to make sure its compatible with SDXC I believe.
Grendel

[Tracey]

Thanks again Grendel. If I get the camera, I'll take a good look through the manual to see which cards it accepts, but just get the smallest one from the camera shop so I can try it out

[Grendel]

usually the camera manufacture includes a small card in with the camera, but do push the shop to get a deal on a 1-2Gb card either thrown in with the camera or at a 'special' reduced price, you will be amazed at how much they can sort out if you only ask - especially if you point out you want to be using the camera straight away, some camera shops do quite good 'package deals' with camera - cards and carry case for an all in price that effectively gives away the case or the cards. after all you are doing them a favour purchasing it from them and not online - arent you?
Grendel