I have to admit, the film is far superior to the BBC version. While I continue to have a soft spot for the BBC series, all nostalgia aside, the acting was terrible. All the children, with the exception of Peter (Richard Dempsey), were melodramatic almost to the degree of amateurs – I'm not surprised that they left the profession after making the series (to my knowledge, only Dempsey has continued as a successful actor). Barbara Kellerman, who played the White Witch, was equally horrendous, massively over-acting her part – she seemed to think she was in a pantomime. The puppet for Aslan was laughable, robotically jerking along, the mouth flapping open and shut in a bizarre attempt to approximate speech. The beavers were hilarious, in overlarge costumes restricting their movement meaning they had to shuffle along, arms held aloft like furry dinosaurs.

Having said all that, the effects weren't bad for 1988. As a child, I thought it was magnificent. But unsurprisingly, it doesn't hold up to the CGI wizardry of the new film at all (compare the beavers, or the cartoon griffin of the BBC to the fully realised depiction in the film). In addition, the acting in the new film is infinitely superior (although the 'Scottish' housekeeper was pretty poor), in particular Tilda Swinton, who at no point descends into ham acting, and the children are much improved. Lucy of the BBC series was all agape, treating the whole thing like a school play. Today's Lucy is actually capable of acting, along with the rest of the cast. Before I looked again at the BBC series, I would have laboured under the misapprehension that it was a work of genius, untouched by time. Believe me, its not – anyone who grew up with it and hasn't had a look since then, do so before imagining it an equal to the new film.

To go into greater depth on the film, there were numerous and significant changes to the plot of the book, many of which were positive. Firstly, the opening sequence; unsurprisingly for a children's book, Lewis didn't go into any detail about the horrors of civilians in warfare. This also marks the first instance of a new backstory provided by the script – Peter's treatment of Edmund. In the book and the series, Peter is generally cast as a mature, slightly over-protective older brother while Edmund is (for most of the book) an entirely objectionable little brat. In the film, Edmund is softened considerably, and in turn, Peter is made less 'noble', for want of a better word. From the start of the film until Edmund's return from the White Witch, Peter is generally not speaking to, but shouting at his brother. Edmund's actions are made out to be reactions against his older brother's treatment of him rather than just an unpleasant personality. I feel the path the film pushes this relationship down is a well-trodden Disney theme – unruly teenagers with 'family problems'. On the other hand, it could be argued that this brings a more realistic element to the sibling's relationship.

These are followed by numerous minor changes, such as the first entry into Narnia is caused by a hide-and-seek game – in the series and the book, Lucy's initial entry is due to exploration, not her search for a hiding place. The cricket is invented, as is the cricket ball through the window and knocked-over armour. Instead of Susan, Peter suggests taking the fur coats, and one other little mistake is the White Witch's pigmentation – she should, as her name suggests, be a very pale white, not merely pale-skinned. Then there is the episode between Tumnus and Edmund in the White Witch's prison, but as with many of the modifications, I feel this is a change for the better.

The main change comes with the rush from the beaver's home. First, Edmund leaves with his coat – the suffering of his cold journey to the Witch, without a coat, was dealt with at length in the book. The party follows Edmund all the way to the castle, rather than briefly searching then returning to the house. Mrs Beaver does not spend hours preparing for the journey, the wolves are right outside rather than coming to an empty house, and there is an escape tunnel. The pub is another new detail (though an entertaining one), as is the character of the fox (presumably based on the old fox at the christmas meal). Needless to say, the fox's role in tricking the wolves is a further fabrication. Finally, the flight down the river, a major sequence, is entirely made up, along with the wolf encounter.

A few religious details are missed out, such as Jadis' parentage (that she is the daughter of Lilith, 'first wife of Adam', doesn't crop up in the series either). More importantly, there is no mention of the 'Emperor-over-the-sea' of whom Aslan is meant to be the son, and who was the creator of the 'Deep Magic'. The stone table section is not hyped up into Christian iconography, but left relatively pagan.

Another important change is the children's reluctance to take up their quest – there is no such hesitation in the book or series. The little scene where the animals have a christmas meal is missing, replaced by the cunning fox. Much to my pleasure, the sexist commentary by Father Christmas was modified – previously, he told the women that 'the battle is not for you', but this changes to a general lament about the horror of war. Susan and Lucy are shown to have skill with their weapons, and Susan even gets to kill a dwarf (the one notable sexist comment is Susan's epithet remains 'Gentle', compared to the rather more impressive titles of the men. However, I can see why the script writers chose to keep it, albeit I'd rather they'd been braver and changed it to something less patronising). The battle is much extended, but as there was little focus on this in the book, there is plenty of scope to add detail.

The film wasn't entirely faithful to the book, but I've has been mentioned, it was a reasonable adaptation, with most of the changes being positive ones that add to the story. Less religious, less sexist, and arguably more realistic in parts.