Which focal length is the best for portraits with a tilt-shift lens?

I use Nikon~ Nikon has 3 tilt-shift focal lengths~ 24~45~85~

Most people think that 24 is suitable for shooting landscapes and architecture~

< p>45 card is in the middle~you can shoot anything~

85 has always been considered the focal length for portraits~ So the conclusion: the public generally knows that the focal length for portraits is 85mm~

But photography is not so "Certain" ~ 24 can also take portraits, with good tension, it mainly depends on the tone of the film you like ~