This post shows the difference between three aspect ratios used in digital photography. The ratios shown here are those available on a Lumix G1. Several other aspect ratios are available in other cameras, particularly in Micro Four Thirds and Four Thirds systems.
|4:3This photo was captured at the G1’s default aspect ratio, 4:3. 4:3 is the most commonly used aspect ratio.
This is the aspect ratio of 35mm film.
|3:2Another common aspect ratio, 3:2, is shown in this photo. Note that at first glance that this appears to be a “zoom” of the 4:3 photo, but it isn’t. The G1 achieves the 3:2 size by trimming pixels from the edges of the frame.||16:9This photo was captured using the G1’s 16:9 aspect ratio. This is also known as the “widescreen” aspect ratio.|
Though the 16:9 photo appears to be wider than that of the first photo above, the 16:9 is achieved by trimming pixels from the frame, so is actually smaller in terms of how many pixels each photo has. For example, the 4:3 frame saved as a 12MP jpeg file, and the 16:9 frame saved as a 9MP jpeg file.