Image size

Recently one of my students was very annoyed because when she printed her photo, that….machine cropped an important part of the image off. This happens because there is a mismatch between the size of the photo that the camera took and the size she chose to print the image.

In many recent digital cameras you may have some choice over image size, especially if you shoot in jpeg. These are set up in one of the menus.

Ratio set to 2:3
Ratio set to 2:3

Here is a scene and what is actually taken by the camera if you set the image size to 3:2




In this gallery the same scene is photographed with the camera set to different image sizes.  To see the full size photos click on one image and then scroll through the gallery looking carefully around the edges to see what is cropped out if a different size is chosen

Now let’s consider what happens when you print one of these images.
At a 2:3 the whole image will be printed if you choose to print an 8 x 12 image (20cm x 30cm). But if you chose to print this image at an 8 x 10 (20cm x 25cm) then some of the side information will be cropped off.

Another example is if you chose 1:1 as your image size in camera you would have a square image. If you then decided to print this image as an 8 x12 print some of the top and bottom of the image would be cropped off.

Which image size to choose.

If you have the option of a 2:3 image size this is the most versatile. It will print a full 8 x 12 (20cm x 30cm) image which is the same size as an A4 piece of paper. It also print the full image in a 6×4 photo which is another standard size. You can also crop this image to a different size such as a square in post processing because you have captured the most information. If you check back to the photos, the other sizes have all failed to capture a bit of the scene.

A 4:3 image size doesn’t easily convert to either the larger size or smaller size and will result in either a smaller photo to get the whole scene in or it will crop a bit off.

A 1:1 image is a square one which has become popular in some web programs like Instagram. If you want to have a rectangular photo later some of the top and bottom of the image will be lost and the quality of the image may not be so good because some information is lost.

The other common image size is 16:9 which is the image size used for video and wide screen applications like the TV. If the image is a different size when you show it on the TV it will just put a black bar at the sides and you will not notice. However if you want to print from this file, you may lose some of the information unless the printer will print a 16:9 image.