When exhibiting a a train show, many visitors want to take pictures. here is a right way or wrong way to do this. The more correct way, and more civilized to boot, is to ask 'can I take some photo's'. Almost all exhibitors will be happy to oblige. if there is a special shot that you would like of a particular loco/train/scene, there's few who will not go out of their way to arrange this. As the old saying goes 'courtesy costs nothing'. There's always others who merrily snap away, but there's not much one can do about this.
Contrast this with an experience on the Saturday last weekend. A chap with a camera with a lens that could have taken pictures of Mars turned up. We assumed he was from a paper of some sort, but it was just his manner and tone that ticked us off a bit. 'I'd like this here, and if you could just crouch there a bit'. 'Whats your name, how do you spell it'. There's ways and ways of doing things, even if you are being paid to do them.
'Photographing the photographer taking a photo'
As a counterpoint to this, before publishing this picture I showed my friend the picture and asked if it was alright to publish this on the blog. If he had said no, I'd be writing a different blog post today.