Chapter 9: Lenses

Focal Length is the measurement of the lens in mm. There are two types of lenses; Prime and Zoom, and three categories; Telephoto, 50 (Normal), and Wide. 

 

 Prime lenses

 

 Have only one focal length 

 

 

 Zoom lenses

 

 Have multiple focal lengths (multifocal) 

 

 

 

 Three Catepgories 

 

 Telephoto 

 50 (normal) 

 Wide 

 

 Going up in focal length narrows the field of view (FOV), while going down in focal length widens the FOV. 

 

 Examples:

 

 200mm telephoto -> 85mm -> 50 (normal) -> 40mm -> 35mm -> 28mm -> 18mm wide -> 12mm fisheye -> 8mm. 

 

 

 Trade offs: for wide angles, it can cause distortion, so the subjects in the frame look farther apart. For telephoto, it can narrow the FOV, making it harder to frame shots & require a higher shutter speed to avoid camera shake.