Wearing a horse shirt and sitting on her horse (this horse is obviously not in the frame) shows this girl's true colors. This shot was taken in good light - a wide aperture lens was not required for the capture. But, the wide aperture creates a strong background blur that clearly separates the girl from the background.
Camera and Lens Settings
95mm f/2.8 1/4000s ISO 100 3744 x 5616px