Portrait lenses, anyone?
“The closer you are, the bigger the nose will be”. So a wide angle lens, which needs you to be close, gives you distorted portraits. On the other hand, an infinitely long lens (say, a 1,000,000mm lens) will give you zero distortion.
Time for examples.
20mm:
100MM
Can you see that the wider 20mm lens, which needs you to be closer to the subject, distorts that subject more? While a longer 100mm lens makes the image look more neutral. In fact, the longer the lens, the less the distortion.
My favourite headshot lens is my 70-200mm f/2.8 lens. For half/full body fashion shoots, it is the 85mm f/1.2 lens.
Fur full body only shoots? 50mm, maybe.
Anything environmental? Wider. Maybe 35, 24, or even 16 or even 10mm. Enjoy!