Cropping is used to make your shots fit the standard photo paper sizes. It’s done by bringing the aspect ratio of your photo to the aspect ratio of a standard print size.
An aspect ratio is simply the ratio between the width and height — the shape of an image. A square photo, for example, would have a 1:1 aspect ratio where the width is the same as the height.
Most digital point-and-shoot cameras have a set frame aspect ratio of 1:1.33 (known as 4:3) when most DSLRs use the aspect ratio of 1:1.5 (known as 3:2).
In comparison, standard photo paper sizes have the following aspect ratios:
6″x4″ – 1:1.5
7″x5″ – 1:1.4
10″x8″ – 1:1.25
As you can see the DSLR aspect ratio fits the format of 6″x4″. In other situations you need to crop your photo.
It is recommended that you crop the photos yourself before sending them to a printer. Otherwise they will use their own judgment what parts of the photo can be sacrificed.
If you need a photo editor, we recommend using GIMP – free open-source software that has been around for quite a while:
for Windows: http://www.gimp.org/downloads
for Mac: http://www.gimp.org/macintosh
Or, PhotoHand can do this for you. We also enlarge photos if needed.