Digital Photo Prints > Aspect Ratio

Aspect Ratio

How to match the dimensions of your photos and your prints

Aspect ratio has a technical name, but is really pretty straighforward. It can be tricky getting your photos set to the right aspect ratios to print properly, but there are many software programs that will help you do it.

Aspect Ratio Definition

The aspect ratio of a digital photograph is the relationship between the width and height of the photograph. There are two common aspect ratios produced by digital cameras: 3:2 and 4:3.

The number before the colon represents the width of the image and the number after is the height. Both numbers represent a relationship, not a specific measurement.

There are other aspect ratios besided the two mentioned here, but they are less common. Some examples of other aspect ratios are 5:4, 16:9 and 1:1 (a square image).

Different digital cameras will produce images with different aspect ratios, even if you don't change the camera settings. Aspect ratios will differ between camera manufacturers and even between different model cameras from the same company.

One Canon camera will capture images that are 4:3 and another will be 3:2. A few digital cameras offer multiple aspect ratios and let you choose which one you want to use for any given photo.

Aspect Ratio Examples

Let's say that I have an image with a 3:2 aspect ratio. The actual size of this image in pixels can be 300 x 200, 600 x 400 or 1350 x 900. So long as the relationship between the width and the height is always 3 to 2, the aspect ratio does not change even though the size of the image does.

Now let's consider an image with a 4:3 aspect ratio. The horizontal and vertical size of this image in pixels can be 400 x 300, 800 x 600 or 1800 x 1350.

3:2 Image4:3 Image
3:2 aspect ratio4:3 aspect ratio

Aspect Ratios and Photo Prints

While it may not seem all that important what aspect ratio your camera produces, it can have an impact on your digital photo prints. Why? The dimensions of photographic prints are basically just aspect ratios: 4x6, 5x7, 8x10, 20x30. All you have to do is switch the numbers (so the width is the first dimension) and then reduce the numbers down to their lowest values.

Print SizeAspect Ratio
4x63:2
5x77:5
8x105:4
20x303:2

But what happens when the aspect ratio of the photo produced by your digital camera does not match the aspect ratio of the print? What happens when you print an image that is 3:2 in the 8x10 print size? Your image gets cropped to fit the aspect ratio of the print.

Original 3:2 Image8x10 Print (with crop area)
3:2 aspect ratio8x10 crop

That's quite a bit of the original image that gets lost! If you send off the original 3:2 photo to get printed, what you get back is the cropped version. That's a big surprise when you were expecting to see more of your original photograph in the print.

So what to do?

What You See is What You Print

There are two things that you can do to overcome the difference between the aspect ratio of your camera and the aspect ratio of prints.

Determine Your Favorite Print Size

If you can determine your favorite print size, you can buy a camera that produces images with the same aspect ratio as the print. If you feel that you will almost always print photos at 4x6, then get a digital camera with a 3:2 aspect ratio. Since the aspect ratio of the camera matches the ratio of the print, no parts of your photos will get cropped when they are printed. The photo you see on your monitor is the photo you will see in the print.

Crop Your Photos Before Printing

When the aspect ratio of your camera does not match the ratio of the print, crop the image yourself before you send it to be printed. If you don't do this, it will be up to the printer to decide how much of the image to keep and how much to crop. When you pre-crop the image to the correct aspect ratio, you ensure that important parts of your photo don't get chopped off.