Number-1
Don’t buy a card that’s larger than what your battery can record.
SanDisk once had a card search engine.
Enter your product model, and SanDisk will roll out your choices.
Check the homepage or products page.
What you really need to know is, Class.
Class 4, Class 6, Class 10.
I use Class 10, its the best.
Check your product webpage for specs.
They should have your available–card choices.
In my Canon PowerShot SX-150is I use a 16-GB Exteme. I get 80-minutes of 720p (.mov)
Over 4,000 jpgs (highest quality)
In my Canon Vixia HF R200 I use 32-GB Exteme for 3-hours of capture time (highest quality)
