Best focal length for PORTRAITS (FX & DX)

What is the best focal length to take portraits for FULL FRAME and CROP cameras? 85mm? 105mm? What are the factors to consider? Meet Cass: MERCH: ThatNikonGuy has been renamed to ’Matt Granger’. If you are already subscribed on social media the name will change over automatically. For new viewers please follow me as _MattGranger on Facebook, Instagram, Twitter, Flickr & Vine. Facebook: Subscribe HERE: http