Back when I wrote about the canon 14mm lens I suggested that the Canon 16-35mm would be better for museum photography.
Well I have now purchased on and after some use I have found that in short it is. 16mm is wide enough for most things while at the same time with the limited interior space in museums its uncommon to hit a situation where 35mm isn’t narrow enough. While f/2.8 isn’t up with the speed of fast primes the high ISO performance of modern DSLRs means that it has to get pretty dark before it can’t do the job. The short minimum focusing distance also comes in rather handy when placing the lens against case glass to cut down on reflections. It is L glass so the usual standards of optical and build quality (although I have manage to damage the filter thread on mine) apply.
On the downside the 82mm filter thread is odd but then I wasn’t planning on using any filters with it so not a big deal. The lens speed also needs watching since f/2.8 can often produce a shallower depth of field that would be ideal for wikipedia.
I spent a week visiting various museums and the 16-35mm was the lens that ended up living on my camera. The 14mm saw some use where 16mm wasn’t wide enough and at the other end of the scale Canon’s 24-105mm saw some use. On the other hand my sigma 50mm f/1.4 was only resorted to once. While the lens works best with objects that are fairly large or medium it can produce usable images of small items with a bit of cropping.
All in all for wikipedians with full frame canon camera’s I’d say this is the lens for museum photography.