Mrs LD and I went yesterday. £10 each to get in and they're a bit prissy about allowing you to take any sort of bag bigger than a thimble around the building with you.
However, what an exhibition.......!!
The place is full of images I'd seen previously but never knew who'd taken them and others (by one of my all-time favourites Andre Kertesz) that are just awesome when you see the actual print - even in comparison to a good book reproduction.
We went in just after 15:30 and came out almost three hours later promising to go back and have another look before it ends later this year. There are dozens and dozens of images, segmented into various groupings. The layout can be a bit of a pain to follow as it's not a simple "linear" walk around. However, if you are in the area, it's a fantastic exhibition and well worth the trip and entrance fee.