Working with Shallow Depth of field of Long Lenses
Shallow depth of filed, one of the most significant characteristics of a long focal length lens when coupled with a longer focal length and shorter distance between the camera and the subject makes Depth of field quite shallow especially obvious when two people are standing at different distances. Close down the aperture, move away, relatively zoom out or reduce the distance between the two subjects to increase the effective depth of field or the area of sharp focus in a photograph.
Typical Long focal length characteristics
Shallow depth of field minimum focusing distance is more Lenses with opened apertures are expensive Flattens the subject Pincushion distortion Narrow angle of view compared to the human eye. As the name suggests- able to see distant views.