For some people, aspect ratio setting on a digital camera got a very little attention. One reason, the lack of understanding about it. Then what is the aspect ratio? Aspect ratio is the ratio of the width and height of an photo.

Currently there are 6 aspect ratio known in the world of photography such as below:

1:1
This square-shaped aspect ratio has a proportional count of width and height. Now this kind of aspect ratio is again used by many photo applications on the smartphone after Instagram popularized it. But before popular by Instagram, 1:1 aspect ratio is the standard size of a Hasselblad camera which has a size of 6x6cm.

5:4
Aspect ratio 5:4 commonly used in large format cameras and camera that use film in the form of sheets. Most sizes resulting image has a size of 8 × 10 inches.

4:3
Media TV and video broadcasting generally use this aspect ratio with size or resolution of 640 × 480 pixels. Small sensor camera and a pocket camera that carries a CCD sensor systems generally use this aspect ratio. Not only that, a camera with sensor size of four third or 4/3 cameras and Micro Four Third (MFT) is also widely use this format. On a medium format camera, 4:3 aspect ratio is also known in the medium format camera “645” refers to the actual size of the image dimensions 6 × 4.5cm.

3:2
This aspect ratio is gaining popularity and used when Oskar Barnack converting negative film to 90 degrees and doubled the width of the frame resulting a full frame negative film 24x36mm, same as the film used in 35mm format camera. Almost all of today’s large sensor DSLR using the 3:2 format.

16:9
16:9 is not a real aspect ratio or commonly used in digital cameras. But that doesn’t mean this aspect ratio can’t be used. Some photographers use it to give a cinematic feel to the photo.

2.35/2.40: 1
This is the most wide aspect ratio and is very rarely used in the world of photography. This is because there is currently no digital camera that supports this aspect ratio. Because it has a very wide size, if in-crop to a 4:3 aspect ratio, then half of your image will be wasted. The aspect ratio can be found on the film in cinema.

Knowingly or not, actually aspect ratio greatly affects the composition of a photograph. By understanding aspect ratio then you will be able to more easily produce images with better composition. Use a different aspect ratio affects the images with different compositions as well. To facilitate your understanding relating to the composition aspect ratio, consider the following simple image simulation that illustrates the composition of elements in a photograph that depicted with circle images.



For an example, this simulation is using aspect ratio 3:2. On the composition above, the large red circle is the main subject.



In this first picture, you can see the images will be on a subject that is a big red circle because it leaves a lot of empty space around it. Then look at the second picture above. Smaller pink circles inserted into the frame and acts as a second subject. In the second picture, the frame still leaves an empty space to the right of the main subjects that still looks less balanced composition.



In the third picture, the frame is filled again with some red circle tinted younger. These circles are placed around the main subject (large red circle) and pink circles as the second subject. The result still looks a little less balanced because there are still plenty of free space.

Well on the fourth picture, the frame is filled with a smaller circles and fill the empty space around it. That way the composition looks to be a full and balanced. If added again a blue circle next to the main subject, the blue circle will not interfere the main subject and the role of the blue and other small pink circles remains limited as a frame filler.

The above simulation was made in order to help you easily understand subject placement and setting composition within a frame. Of course this is just a theory, and the best way to understand it is to shoot as much as possible with respect to the composition.

The rules of composition in photography in general is hold on rule 3/4 or better known as “The Rule Of Third”. But actually to produce a photograph with good composition, you can bypass the restrictions and rules. So try to experiment and take a lot of photos, compare them before and after you understand the theory of composition related to the aspect ratio. Good luck!