What size should a digital picture be to get best results from a printer/copier.?

We have a Canon Image Runner printer/copier/scan/fax. What size should a color digital picture be shot with a Casio Exilim 7.2 megapixel camera for best results. I want to get as many pictures on a memory card as possible so I don’t want to make a picture larger than necessary.

You should never EVER set your camera to anything less than best quality (i.e. lowest compression rate) and biggest size (highest resolution).

The reasons for that include:

1) If you have a good, large photo, you can crop it more later on without losing too much detail if you really have to.
2) If you happen to take the best photo you ever took, you’ll be able to print it at a large size. If you lowered size and quality, you’d be kicking yourself.
3) If you decide later you really don’t want to keep a big file, it is very easy to down-size it in post processing – but you can’t go the other way, you can’t invent pixels that weren’t there in the first place.
4) Memory cards are cheap, so are bigger hard drives. There is NO reason to do anything less than the best.

By the way – the part that counts for printing is actually the dots per inch (at least 240 dpi is best).