Are all correct? Any difference in meaning?
1 I found him to be sitting by the fire.
2 I found him sitting by the fire.
3 I found him to be a swindler.
4 I found him being a swindler.
(2) is more natural than (1), because we usually use found him to be in relation to a personal quality (as in (3)) rather than a temporary situation.
(4) is unidiomatic. (It implies I found him in the act of swindling someone, but it's not a natural way to say that.)