Unlike other composition guidelines such as rule-of-thirds, leading, centred composition, or foreground interest, the visual weights & balanced composition guideline is less known by many people. (Which I'm a bit surprised when I did a few surveys about it during my sharing sessions)
Visual weights & balanced composition play a huge role every time when I'm composing my shots. I personally think that it is even more important than the rule-of-thirds guideline, which is the most practised composition guideline by the photographer).
Let me give you a quick example here.
Here is a photo that has two buildings on it. The left one is our Malaysia prime minister's office, and the right one is our famous Putra Mosque (also known as Pink Mosque). Before you criticise the photo is overexposed with bad image quality, I want to let you know this is just one of the test shots that I did to find a good composition. I need you to ignore the distracting green colour at the bottom and any overexposed and underexposed areas, but focus only on the composition.
Looking at the photo, I want to ask you a question. Is this a rule-of-thirds composition?
If your answer is yes, congratulation. It is indeed a rule-of-thirds composition.
But, I want you to look at the photo again. Do you feel that there's something not so right about the photo, but you can't really explain why?
If yes, no worry. There's nothing wrong with what you feel about the photo. It is something explainable, and it is related to the photo composition.
Before I explain that, let's talk about what's a visual weight first.
Visual weight is about how much visual impact an element on your photo has. In other words, how "catchy" the element (or a subject) is?
The visual weight can be affected by things such as size, contrast, colour, clarity and tone.
Look at the photo again. On a scale of 1 to 10, we will decide the visual weight of the two buildings in the photo. Ten has the heaviest visual weight, and one is the lightest.
We will start with the Putra mosque on the right. First, the mosque is huge in the photo and has a unique design, brighter and more colourful. So, I'm going to rate it 8.
Now, if we look at the Prime Minister's Office, the building is smaller, less noticeable, and not so interesting compared to the mosque, so I'm giving it only 3 out of 10.
With left side has only a subject with a lighter visual weight and the right subject has a heavier visual weight. The photo appeared to be imbalanced. It is also why you don't feel intuitively comfortable about the photo (same as when you look at a heavily distorted building), even though it is a rule-of-thirds composition.
Next, we are going to look at the photo that uses the rule-of-thirds composition. Similar to the previous photo, we have two subjects on both sides of the frame, the horseman and the horse.
Unlike the previous photo, both the horseman and the horse are equally interesting, share a similar portion of the frame and are equally bright. I give 8 to the horseman and 9 to the horse because I personally like the horse more, and it has beautiful highlights around the edge.
The photo's composition is balanced because both the left and right sides of the frame have subjects with similar visual weight.
I hope my above explanation will give you all a better understanding of how visual weight and balanced composition work. It is how you create equilibrity and harmony, which is intuitively comfortable for the viewer.
Because of that, every time you take a photo, please take a bit of time to look at the composition, and check whether it is visually balanced, regardless of what compositions are you using.
The more you practice, the better you will be at getting a good composition.