My family's going on a long vacation soon, and on impulse, I bought a digital camera (my first ) and a 2GB SD memory card for the camera. I was wondering though, if I take pictures at the default setting of 4 mega pixels, how many pictures would I be able to store on the SD card?

It depends on the subject you're shooting, the more colors/detail, the more space the picture will take up. If you take one or two shots with the SD card in place, the camera should tell you how many shots you have left. To give you a rough idea, my current 5.1mp camera on its "best" JPG setting averages about 2.5-3mb per picture (the resolution is something like 2900x2100) so my 1GB card holds around 500ish pictures.

On the other hand, my older 2.1mp camera had an option to take pictures as an uncompressed TIFF file, so each picture was over 10mb.

I don't know what camera you got or the specifications, but I was able to find [url=http://www.steves-digicams.com/2002_reviews/hp812.html[/url] about an HP photosmart something or nother. Scroll towards the bottom, past the views of the camera to the specifications table.

Well, that's pretty easy.

4 million pixels x 4 (32-bit color depth) = 16MB per photo, if they're uncompressed raw images.

If they're jpeg, that will be much smaller.

My camera is just over 6 megapixels. I shoot in the largest format using RAW. I get about 90 shots on a 512MB card. So, at 4 megapixels using jpeg you are looking at several hundred photos on a 2gb card.

On my last trip to Vegas I used my old 4megapixel camera and took around 100 photo's and about 10 minutes of video and barely started filling a second 512MB card.

if I take pictures at the default setting of 4 mega pixels, how many pictures would I be able to store on the SD card?With default settings, you'll get about 800-1,000 on a 2 Gb card. This is assuming average JPEG compression of 8:1 (the "normal" or middle setting, not a fine setting) at 4 megapixels. The "fine" mode will usually double file size, so you'll get maybe 400-500. Look on your camera, most have a counter that approximates the numbers of exposures left.4 million pixels x 4 (32-bit color depth) = 16MB per photo, if they're uncompressed raw images.I doubt this is relevant to the lead post, but unlike JPEG, RAW can be more than 8 bits per channel (on my camera it's 12 bits). It's also compressed with lossless compression. At 10 megapixels each 36-bit image usually comes out just under 10 Mb.