Which wide & fast lens...?

Since the other topic got locked (a bit odd, since John had posted in it himself, but never mind!), this is a follow-up to my previous post there.

I've had a look at the shots I took at the one wedding I've done. Of those shots taken during the ceremony itself (and as I said in the other thread, this was in a room with lots of windows on a sunny day in August) 57% of the photos were taken at the widest end of my kit lens (18-24mm is as precise as ImageReporter tells me, since it rounds to the nearest 10mm). Although your experience may vary, this does perhaps suggest that something like a Sigma 30 f1.4 or a Pentax 35 f2.4 will not be even nearly wide enough.

The big question that you HAVE to know the answer to (and if you could tell us it would help us advise you!) is whether you are allowed to use flash during the ceremony or not.

If your budget will stretch to the Tamron 17-50 then get that: it's a very good lens indeed. The only proviso I would add is that if you are going to order one you should do it sooner rather than later. This lens sometimes has front-focusing/back-focusing issues on arrival so you need to have time to test the focus accuracy and if necessary exchange the lens before the wedding. (In fact you should do this for any lens if it's going to be used for crucial work)

I would like to continue this post with another question. I hope this will not mind the initial author, I thought it is connected to the subject and is of no use to open a new one.
So, which lens do you think will be more appropriate for such an event: a Tamron AF SP 17-50mm f/2.8 XR Di II LD IF, or Tamron AF SP 28-75mm f/2.8 Di XR LD Aspherical IF?
Regarding the optical characteristics (sharpness, distorsion, vignieting, etc), I found them quite similar, according to the reviews I found. Some authors said one is better others preffered the other one. I did not use any of them, so I have no ideea which is sharper.
Regardind the focal range, I guess on an APS-C might be some "problems" for the 28-75, as it will be quite difficult to make photos for large groups, so 17-50 might have a big plus on this. On the other hand, the 28-75 might bring more satisfaction on portraits.
So, what is your opinion, as experts, on this choice? If you have to choose one, which would be yours?
Many thanks

MrCynical, its an asian wedding, not a po faced Scottish Presbyterian one , the use of flash wont be an issue.

In the ceremony itself there is less need for a wide lens. I used the DA16-45 in order to get a view of the entire church from the balcony, but other than that you need reach to get details at the altar and so on. I would say the 28-75mm zoom would serve you better, though 75mm may not be long enough depending on where you are allowed to stand.

At the reception, preparation of bride & groom, formals, etc. it is often necessary to get in close or cover lots of people in a scene. There I have used the DA12-24. Be careful though in group shots not to have people near the frame edge when shooting wide. It is not flattering!

Really, one could do the whole wedding with a DA12-24 and DA*50-135. And maybe a fast 50. It goes without saying that you need two bodies.

I haven't actually been to an asian wedding that took place in a church with balcony and altar. First time for everything I suppose...

Ah sorry, I missed that last post before replying! Only speaking from my own (limited) experience. Every wedding is different with different rules and expectations of conduct as a photographer. Important to check with officiant beforehand to get it all straight. And to do a site visit to see what focals are required.