I do not need the photos for commercial use, but to compare the details with other temples, for an essay I am working on. It is impractical to have to go onto the net and go through the whole series every time I want to check a detail, so I have taken copies for my private study. If I actually need to reproduce one or two within the essay, I will write first to ask your permission. When the essay is finished, I will remove the pictures from my computer. I have put them in a separate folder, with a document recording your name and web-address, which will be cited as a source even if I don't need to reproduce any pictures.
Trust that's ok.
I can answer: such use is OK. You do not need to delete pictures, I do not want people to use them commercially without my knowledge, but private people may download them to their hearts delight.