Every photographer has a different opinion on this. I can say my favorite size flashcard to shoot with is 2.0 GB. I only use the Sandisk Extreme cards, though Lexar makes an equally fast model. When I bought my first 4.0 GB card a few years ago, it was nearly $300. You can find them now for about $40-50, but I will say the 2.0 Cards are better….why?

1. A 2.0 card will hold close to 1000 images if you are shooting in JPEG (jagged) which I do. (another entry)
2. A 4.0 card will hold twice the images, hence, if the card goes bad or you lose it, twice as many images are gone.
3. A 1.0 card will have to be changed too often (I normally shoot up to 2500 images in a wedding)
4. A 4.0 card also sometimes stalls on certain systems…..like my PC for example.

On a normal shoot I will have to change my 2.0 cards once, and they go into a GEPE waterproof card safe. Even though they now make 16 GB sandisk cards, there is something that makes me nervous about putting all my eggs in one basket. Unless you are shooting with a 5 D or higher, 2.0 is here to stay.