Some real gems on this site, including this revealing online gallery – John Loengard: Celebrating the Negative, my favourite is Cartier Bresson’s  Gare St Lazare.

The revelation for me was that you can see how much of the negative has been cropped at the bottom and left side in the prints of this familiar and iconic image – I was at a photography college (a long, long time ago) where the frame was sacrosanct – you didn’t crop, you put your negative in a holder that was a bit larger than than the neg size and allowed the light passing through the clear rebate to create a dense black frame round your image to prove you had kept it intact; a curious form of celibacy; took me years to reject the concept.

By contrast, but a great companion to the above – less ‘fine photography’ but lots of fun, and food for thought: Red Bubble recreates famous photographs – with lego