Originally Posted by MattKing
For environmental portraits, this may be correct.
But it can gives some strange results.
When younger, I had a very experienced photographer tell me that he wouldn't hire a wedding photographer who didn't at least have a prism finder available.
If you use a waist level finder, there is a tendency to end up with a "naval eye view of the world" in your photographs of people.
Which definitely doesn't result in the most flattering view of many wedding guests - including many mothers of the bride!
Food for thought, but I probably do not agree. To clarify, I am talking about full body images, not shoulder/face portraits. I can see the point for the latter.