http://www.techradar.com/news/photography-video-capture/best-portrait-lenses-8-tested-1136086

Professional portrait photographers may favour top-money lenses such as the Canon EF 85mm f/1.2 or Nikon 85mm f/1.4G, but with both costing over £1,200 ($1,450 or AU$1,800), they can be pretty pricey for most of us to justify.

Thankfully, there's plenty of choice to be had if you don't want to break the bank, with a range of prime (fixed length) lenses that are affordable but still very capable.