Personally, I format the card on first use and after I have downloaded the images from the card. I do so on the camera, not on a computer or other device - that makes sure the format matches the camera's file system
I recommend the following procedure in dealing with cards:
1. Before first use, format the card on the camera
2. After shooting the images you want, remove the card from the camera, connect it to a computer (Ebiggs1 is correct a USB reader is the simplest) and download the images to your hard disc. Make sure the images are readable on the computer. Don't just pull the card out of the reader when done - if using a Windows machine, use the Eject feature (right-click on the icon for the card to see this option). If the card is still in use you will get a message that it's not safe to do so, in which case close any programs that might be using the card before having another go.
3. Remove the card, put it back in the camera and format it, ready for the next shoot.
It is not a good idea to just delete all files. The way that deleting works is that it simply removes the first character in the file name and that tells the camera file system the space is now available. The problem potentially creates is the accumulation of damaged file entries that will create a risk of a read/ write error.
I hope this helps
cheers, TREVOR
The mark of good photographer is less what they hold in their hand, it's more what they hold in their head;
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
