Period drama nowadays goes to extreme lengths to ensure accuracy. In every area, that is, save the ecclesiastical. There, I’m afraid, one is still likely to see a scene from a Jane Austen novel with the clergyman conducting a funeral wearing a green chasuble over a lace-trimmed surplice! Such inaccuracy is born of two things: first, that the producer (probably middle-aged and with some vague memory of his public school religion) thinks he knows what is and what is not; and secondly, that he doesn’t really care because its only ‘religion’ and no-one else will make a fuss any way. So we are back (for the ‘religious’ scenes anyway) with the 1950 films of Robin Hood, with the hero in green crimplene, and the heroine with bouffant hair-do and too much lipstick!
In the late 80’s I was for a few weeks unofficial (and unpaid) adviser to a film company making a film in Docklands. I helped them gather together the furnishings to create the sets within a redundant church. They were to film several scenes of clandestine meetings of the terrorists in a back-street Catholic church. The artistic director was quite happy with the flickering pricket stands and the statues. The following day, he said, he would get the florists in to do the flower displays … I interrupted, saying that this would be quite inappropriate and that we just needed four large rubber plants. He went up the wall, telling me that this was not what he wanted at all! What price historical accuracy?
I suppose what gets me is the assumption that in the area of ‘religion’ it doesn’t matter, and that no-one will notice anyway. It’s not so much that the several million Christians in the UK will take to the streets at the sight of Tudor bishops eating their lunch wearing copes and baroque mitres. It’s that the media establishment just doesn’t know and doesn’t care that there is such a thing as the Church, and that millions of people belong and believe. They ‘don’t do religion’. And because of that their productions are not as good as they could (and should) be. But on the other hand they also produce moments of real hilarity for countless Christian viewers. Not that they ever meant to, of course.
Ordinariate Pilgrim 
Yes you’re quite right about the assumption that religion doesn’t matter and that it’s only for the eccentric few. Glad to see you’ve posted a pic of Derek Nimmo in one of his several ‘wet cleric’ roles which more or less sums this attitude up. I did enjoy All Gas and Gaiters with Robertson Hare as the Archdeacon and Nimmo as the Bishop’s Chaplain.
That aside, it can be hilarious at times, spotting the ‘blooper’. One of my favourites is from Dad’s Army where Captain Mainwaring conceals a pistol underneath a chalice veil leading a procession of his troop all dressed in cassock and surplice and singing.
Co-incidentally, there was a comment in the Telegraph today along the same lines as your post complaining about stoles being worn on top of the chasuble (not just in drama, but sadly in real life) and speculating that the Church in Midsummer must use more candles than the Vatican as every church interior is always candle lit even outside service times.