There are 2 types of SD cards,

1.) regular SD (Secure digital) cards come in 512mb, 1GB and 2GB
2.) SDHC (Secure Digital High Capacity) cards come in 4GB, 8GB, 16GB and 32GB.

The answer is in your manual, if it says it supports SDHC, that means you can use between 4GB and 32GB. If it says only “SD” then 2GB is the “biggest” capacity card that you can use with your camera.

Personally, if you are going to use it only for still shots (not video), just use 4GB. Sometimes high capacity cards has a bit of delay saving the image files after each shot esp if you have to much files in the card. I don’t even leave my files in the card. I immediately transfer them in to my harddrive. I don’t trust keeping important shots in my SD card. I have an 8GB but I rarely use it. I just use the 4GB. 8GB is just a backup.

I purchased the Canon Rebel T1i earlier this year. This camera will support Secure Digital (SD) cards with any amount of GBs. The one thing to look for when purchasing memory cards is the transfer rate. The reason why I bring this up is because this camera can take HD video and you will need a memory card with a faster transfer rate for recording videos so that the videos do not appear choppy.
Having a faster memory card will also allow you to take advantage of the continuous burst rate while taking photographs as well.
Wishing you a pictre perfect day!

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