Convention Lens Selection Help

Ok so after many years I have decided to embrace my inner geek. I am headed to the Star Trek convention in London this October and need some help deciding what lens to use. I bought the VIP ticket so I'll have front row seating in the main hall. I'll be in a full Star Fleet uniform so I don't see myself caring around allot of gear. So my question to you is with a 5D MkII what one lens do you think would be most useful to carry, I realize one lens can't cover the vast lightning changes or the all the different distances but work with me here???? Cost really is not an issue.

I'll be the first to admit I am a beginner with expensive gear but I'm working on getting better.

Thanx for any input/thoughts/opinions, have a good one. :)

I recently attended a comic convention here in Australia and it was a real blast, with terrific characters to photograph. I took a 70-200mm 2.8 and that was very useful in the subdued lighting, but the best lens would be a 35mm or 50mm fast prime. That will find the light for you and give you the sharp shots that are needed.

There is very little room at these sort of things and you rarely have more than 1-2 metres to back up from the people. Sure the 70-200mm is useful for the stage shots, but I found my best shots were from just stopping and asking other attendees if I could take their picture.
This girl was happy to pose with not much space.
[img]http://farm9.staticflickr.com/8142/7...e8981b6a_b.jpg
Are you looking at me? by Steve's Life, on Flickr[/img]
Same story here.
[img]http://farm7.staticflickr.com/6118/6...61941141_b.jpg
Come with me, I know... by Steve's Life, on Flickr[/img]
Have fun, good luck with it.

I'd go with either a 35mm f/1.4L, or for the smallest package possible, the new 40mm f/2.8 pancake. The latter delivers surprisingly good IQ, and the high ISO capabilities of the 5DIII are a good match for an f/2.8 lens (yes, f/1.4 is two stops faster, if the thin DoF works for your shot).

What if you went about it the other way and changed the body to fit the need. I've never used a 5d2, but some folks had problems with poorly lit rooms. If you're still new to the game, you could get a 5d3 and let it make up the difference with a better focusing system and better noise performance. The silent shutter does sound a little better too if you don't want the whole world to look at you as pieces slap around in your camera.

I would consider the 24-70mm f/2.8L. Great IQ and versatility but no image stabilization. Using the high ISO capability of the 5D2 you should be able to get enough shutter speed so that image stabilization is not crucial.

Cool guys thank you for your thoughts I appreciate your time I'll try and find some simiular indoor venue's around Houston before October and try out your sugestions.