In street photography I think there’s some misconceptions about focal length. Oftentimes people get caught up with which camera to use, which lens to use, and for which situation they are best suited. I actually believe that it doesn’t matter which focal length you choose for the day, as long as you stick to one and one only.
Set limitations
In order to improve your photography, I believe that it’s best to stick to one lens. This is a pretty basic approach, but will allow for incremental improvement over the years. I think that the more you focus on one focal length, the more you become connected to your camera. Treat the camera and the focal length you choose as a connection or an extension of your body and your mind. Just think, you’re not looking through the viewfinder constantly as you’re on the street scanning the world for compositions. You’re merely raising the camera to your eye to press the shutter when the moment is in front of you. Because of this, the focal length does not really matter at the end of the day. What matters is your connection to the camera itself. Are you comfortable with using this exact focal length? I believe this is a much more interesting approach. To focus on the connection that you have and the distance you are to the life in front of you, rather than numbers and technicalities.
When you set a limitation to use only one focal length for a period of time, or for a specific day on the street, you’ll find yourself in a flow state. It’s important to achieve this state when photographing because you focus on the fleeting moments around you and less about the gear. The more you’re fumbling with your settings, or changing a lens, the less photos you will make successfully.
Set limitations. Use one focal length for one year. You will improve.