Film critics are a very strange breed. Deprived of natural light for much of the working week, the profession is more exciting in the telling than in practice. Reluctant to enter into discussions at the end of a film, most reviewers guard their opinions like children shielding exam answers, but there are always one or two who are willing to provide scene-by-scene analysis from the front row.

The late Roger Ebert was famous for pontificating as the credits rolled, but as the only person to have won a Pulitzer prize for film critiquing, he was well within his rights to tell everyone what to think of a movie. And now Ebert is the star of his own film - albeit posthumously - and there's no telling what star-rating he would have given Steve James's documentary.

His fame pre-internet was in the US where for many years he hosted a review show with the equally-opinionated Jewish critic, the late Gene Siskel. It was their acid disagreements about films which made them so popular and highlights from their TV shows are part of this Scorsese produced doc, which explains Ebert's fascination with films and his championship of independent cinema.

I would have liked a lot more of that along with samples of his reviews to see if we shared the same taste in movies. Instead, we see Ebert undergoing painful medical treatment as he battled the final stages of throat cancer. While we can only admire his ability to continue working through his illness, only those closest to Ebert should have witnessed his horrific demise at such close quarters.

There are many moments for cineastes to enjoy, but I do not believe that this is the way to remember a revered critic.