It's been sprung on me that I have to go to London for a business trip. As such I'll be carrying a load of things for work so camera space is extremely limited. I was planning on taking the 5D MkII with 24-105 because it has a good focal range, less obvious than a white lens and is (reasonably) small. Alternatively I could take the 70-200 f/4 IS or 50 f/1.4. In the main I'll be looking for architectural / cityscape shots. I'll be in conferences all day so will only be shooting from 6pm onwards - low light at least. As well as not having capacity for extra bulk, I'm not familiar with London so will be wearing it on an R4 slung under a coat for a bit of discretion. Thoughts? Opinions? 24-105 or 70-200 or 50? Anything else I should be thinking about?