We all know that you can make nice photographs with just one light. But is that sustainable at all? Aren't you too limited?
There's no formula for having a sustainable photography business. It all depends on your portfolio and how you show it to your potential clients. You can't have a profitable business without a good portfolio though. This is one of the approaches to keep the wheel going: create a variety of images. When I say "variety" I don't mean different subjects, but rather present different ideas. You can have several images of a beautiful girl in the park with a blurred background but if all of your gallery has only that type of photography, people can lose interest very quickly. The human eye likes to see different things and if you want to keep people watching your images, you have to provide a greater diversity.
One Light Is Old School?
I used to limit myself that having just one light doesn't give me the opportunity to produce captivating images, because I might need more lights. I thought impressing people would be only though complex lighting. These were the days when I was into the "Dave Hill look" when I thought the most interesting portraits could be only created with several lights creating unrealistic and conflicting shadows. At the same time one-light photographs were too conservative and casual to me.
Too Limited by the Light
Time went by and I found that light was just a tool to draw an idea, not the idea itself. I know this may sound as an obvious statement, but many times photographers think only about light and thus they are limited by light as a technique. This is like to only use wide open aperture and shallow depth of field and miss many other beautiful compositions with a deep field of focus. Pictures are like storytelling. You may like to use different pens, nibs, and inks but if you are telling the same story you will be a boring author.
Story First, Lighting Second
If you keep the story at first place you won't be too much worried about the fact you have one or five lights. Look around on a sunny day. You are seeing various stories with your own eyes. How many lights are used to light those stories? Just one, the sun, but with lots of fill light coming from natural reflectors — the ground, buildings, trees, water, dust, etc. This means that you can tell most stories with just one light source and eventually a few reflectors.
If you're worried you can't have a sustainable business with one light, you should be worried you can't have a sustainable business with just one car. If you need to go off-road you will have to have a truck to be able to transport yourself and your gear. The truth is that you can do a lot with just your car and if you use it wisely you will save up for a truck. But are you sure you need a truck and not a minivan?