Employers ask questions like this one to discern whether you are looking for a job you care about or just a job. Art thrives on emotion, and photography is a form of art. If you aren't passionate about what you do, then the employer will likely want someone else. Therefore, the best way to answer this question is by being open and honest. If someone triggered your interest in photography, share that. If a class assignment or situation led to your interest, be specific and share that. If you can show a clear emotional interest in the subject, you will win the employer's attention.

"I chose to become a photographer because I believe in the idea that a picture is worth a thousand words. However cliched that statement is, I find that taking pictures of life helps capture the best moments. Everyone has their memories of good and bad experiences, but over time we forget the details. We forgot how people looked, how we looked, how places looked. Taking a photo captures the moment forever. I think that's priceless."