1. What is the difference between a Formal, informal, environmental portrait?

A formal portrait is when the person in the portrait appears really formal, nice dressed and mostly honest posed with a direct look into the camera. It was most likely used in the beginning of the camera ( ~ 1850), because the cameras where not really good developed so the person had to stay in the same position a really long time, because the shutter speed was incredibly slow.
Informal is when the person is more in any position or does not look into the camera. The position of the hands can tell us alot about informality or formality as well. Hands deep in the pockets and a relaxed position is definitely a lot more informal than straight arms down to the side and a stiff body.
An environmental portrait is showing the person in its normal environment and not posed. a good example is the president in his office in the White House beeing bussy talking to somebody.


2. What do the eyes tell us?

They show us if the portrait is posed and if the picture is formal or informal.
A direct eye contact into the camera seems more formal and a look to the side more informal.


3. What does the background and body position tell us?

The background tells us a lot about the person and about the kind of portrait. Often the background is supposed to have a special effect, like telling us something about the person. In a formal portrait the background is most likely plain.
The body position tells us whether the portrait is formal or informal.

4. How does the lighting affect the shot?

It can create a special mood. for a good formal portrait we need good lightning for showing detail, otherwise the lightning can be special.