Below you will see a high
resolution photo taken with a 5.1 megapixel
camera. (850k file size)
To the right is the same photo taken with a camera phone. (39k file size).
They both look relatively good from a distance. However
the photo at the bottom shows the difference
when they are both made larger for a life size standup.
Her face is still very clear on the left, but becomes very grainy on the right side.
This is why we ask for a high resolution digital photo or a negative when ever possible.