If you love the series this is based on you won't be disappointed (unlike some other tv to film adaptations). The scriptwriters have very smartly avoided the usual trap of taking the characters that work so well on the small screen and putting them in a ridiculous situation that so many other films (like On the Buses) have done with usually poor results. The photography does have a stark realism to it (it certainly looks very cold) and the colour scheme gives the film a certain bleakness but as the film is set in and around a prison it doesn't really take anything away and won't spoil the enjoyment of watching Fletcher and co get up to their normal tricks.
The story fits in well with the characters and settings. Almost all the familiar characters from the tv show are here and having Dick Clement and Ian Le Frenais write (who wrote the original tv series) write the film script keeps the continuity of characterisation and wit going. As usual Ronnie Barker totally steals every scene he is in, even against veteran character actors like Fulton Mackay and Peter Vaughan (as Grouty). The whole thing is an almost seemless transition from tv to silver screen with some wonderful funny dialogue and charming supporting actors thrown in (including a very young Daniel Peacock as a newly incarcerated inmate).
There is a sadness knowing that Richard Beckinsale passed away at the ridiculously young age of 31 just weeks after filming wrapped but at least the film doesn't dishonour his memory. As a swansong to him and as an adaptation to probably Ronnie Barker's most beloved character this film doesn't disappoint, even if the tv series is still marginally superior.