Understanding Lenses: What is Focal Length? - The Beat: A Blog by PremiumBeat
How Focal Length Can Dramatically Change Portraits - Digital Photo
File:Orthographic camera distance focal length.gif - Wikimedia Commons
The Power of Lighting and Focal Length in 4 Compelling GIFs » TwistedSifter
4.3. Explain the effect that the use of different focal length lenses has on a photograph
Safwan AhmedMia on Twitter: "For those who don't understand focal length and keep saying "You don't need to use the Telephoto Lens for Portraits, just move closer!" 🤦🏽♂️ This GIF from @parkerwalbeck