Weather sealed? 17-40 would be my pick with a filter. Shame in a way because that can potentially exacerbate flare but I think ultra wide is the way to go for night work... That's my preferred style anyway. Most things on my page are shot with a 17-40 although I rarely light paint.
I checked out your work,pretty amazing stuff how do you go about shooting i mean settings gear,lights if any ,postprocessing etc
I guess you have shorter exposures ,under a minute.
P.S : how sharp would the 17-40 be on a 7d ??
Thanks for that - most of my night photography is at least 2 minutes. Some exceed 6-7 minutes. Settings-wise:
ISO200 (normally), no filters at all, 2 minutes on average, F8. Post processing for colour and contrast etc - only levels and curves and some selective dodge and burn. Mostly just Lightroom workflow (99% of the time).
With regards to the lens, I think the 17-40 would arguably be sharper on crop given the edges are cropped away (which are the weak bits on FF) - but it would not have the dynamism of UWA on the 7D. I used a 10-22 for a few months on my 550D and I loved it for night work however the 17-40 on the 5D2 is a step up in IQ undoubtedly (for me). I have seen people here say the contrary but I just do not see it - the images are 'deeper', sharper and more contrasty. With regard to night photography, the 17-40 handles flare much better and starbursts are cleaner and punchier. 10-22 starbursts were always filled with untidy globules of light whereas the 17-40 ones are cleaner and just 'glow'.
So with regards to night work, I would thoroughly endorse the 17-40. A lot of people are critical of this lens and consider it inferior to the 16-35. For day work (and photojournalistic work) I suspect there might be something (vaguely) in it however for night work, this lens is a winner. Night photography makes most lenses look good
and this one is no exception.
Whilst I have a nice collection of primes and love using them for day/portrait work, I would be lost using them at night. The UWA zoom is an essential part of my work at night - as I do not have time/luxury to compose slowly and thoughtfully. The wide angle potential allows leeways, especially in tight spots.
I would be slightly wary of capping the 17-40 with a filter though, as you must to weatherproof/resist it as it may make it more prone to flare. I don't believe the 10-22 is weather resistant, regardless?
That said, the 17-40 is a great lens on FF but I feel it's a bit boring on crop. Which kind of defeats the purpose of having a flexible UWA lens for night work. I suppose it depends on what you plan to shoot (and how).
Hope this helps in some way!