I think there is a problem with translation. ''Filmul'' is singular so the verb ''este'' is. The given translation is in plural. Is that correct?
"Filmul" here is used to refer to movies in general (cinematography), not a particular movie; a construct that has no straight-forward correspondence in English.
Just saying 'Film is his passion' would make sense (be correct) if you are talking about the hobby/work of cinematography in general.
I'm not a native English speaker, but I've never heard this form. It sounds ok, but "movie is his passion" sounds wrong.
There is a difference between "film" and "movie" to a native English speaker. Generally "movie" refers to a single movie, whereas "film" can refer to the entire genre of cinematography.
Indeed, it should be Filmele sunt pasiunea lui to be translated as Movies are his passion.
It may be that as in Italian, film acts as a singular noun even when talking in the plural. It is determined by context. I think this may be because it is considered an uncountable noun in these languages despite the fact that you can actually count 1 film, 2 films, etc