I am a frequent visitor to the cathedral in Durham and it is one of three I believe which don't charge. People get quite stroppy that they can't take photos.
Just before evensong on Sunday I had taken a visitor from Australia there and a japanese couple were busy taking photos . They had already been asked by a bedesman not to take photos. I quite agree with Mollie how many photos are stored and never viewed. The photos your brain takes are generally better quality
I deserve a round of applause!