If you shoot raw, then it pays to go at least 2 GB ... you'll get
something around 120 images (RAW+JPG if that's how the D20 stores them).
 4 GB, double that (obviously).

I shoot a 6 MPix camera on a 1 GB card (81 Raw + 81 Hi-res JPG) and
that's marginal for some situations.  Luckilly I've had my laptop with
me when it counted...

Cheers,
Alan.

"cameragal" <mattearoadie@aol.com> wrote:

I shoot RAW-only with a 20D and use SanDisk Extreme III cards. I do
not shoot RAW + Jpeg.  I did that initially but I never used a single
one of the Jpegs so I quite doing it.  I shoot sports a fair bit and
like the speed of the Extreme III cards.  I originally bought 2GB
cards but when 4GB became available, I bought that. If I get another
card, it would be 8GB.  An 8GB card will hold over 800 RAW images
from the 20D.  I use about 6GB shooting a hockey game or a Rugby game
and when shooting motor sports with bursts of 4 or 5 frames,  per
car, about 90 bursts will fill a 4GB card.  I also found myself in
need of a card once and could only find a 2GB GXT Digital Pro card
from Future Shop.  I bought it and to me it seems indistinguishable
from the SanDisk Extreme III cards.  I use a SanDisk 12 in 1
ImageMate card reader.

Unless you get into continuous shooting situations where you fill the
camera's buffer you don't need the fastest of cards unless you want the
ultimate dl speed to your computer, assuming your connection method
supports it. If you care:
http://www.robgalbraith.com/bins/multi_page.asp?cid=6007

The cheapest.  Unless you're shooting long bursts why pay vastly more
for an "extreme" card?

Does Canon certify certain cards. I know Nikon only certifies SanDisk
and Lexar, though the two companies probably paid for this if you have
a read - write error with any other card Nikon will just say
"uncertified card". I use San Disk Ultra IIs with my D200 and they work
fine, less expensive than the Extreme series. I have used Kingston
Elite Cards too with no problem. The truth of the matter is that CF
cards are fairly bullet proof, but occasionally do fail. Really cheap
cards are alright for older cameras, but you need some speed to keep up
with faster cameras like the D20.
A faster card will help your download times too. I have access to 7
computers all have a card reader, all from different manufacturers, the
only obvious advice is to buy a USB 2 reader. 2 of the computers have
USB 1.1 readers and the download speed are so slow on these.

Have fun
Tom

Sandisk Cards.

An Extreme IV, if you can afford it (alone with the Sandisk Extreme
Firewire reader), and if you value the CF--->PC transfer time.

Otherwise go for Extreme III or, better, Ultra II and save some money

And remeber, 2x2GB is better than 1x4GB, both for safety reason (if one
card goes nuts, you still have the other one, and you have lost only
half of the pictures), and for performance reasons (2GB cards are the
fastest, even if by a small margin).