I posted this in the lens forum as well, but wanted to post it here to get a more wedding-oriented view...if that's not OK I will delete it.
Right now I am deliberating between the 70-200 f4L IS and the Sigma 85 1.4
I currently shoot with a 40D, my main lens is the Sigma 17-50 2.8...great lens. I also own a 50 1.8, sigma 70-300 f4-5.6, and the 18-55 kit lens.
I have started to do some paid photography, I did a wedding, an engagement shoot, senior pictures, and family portraits last year. I've got at least two weddings that I am for sure shooting this summer, possibly three.
My issue is what new lens to get. I need something longer than my 17-50 that is good quality. Not only is the sigma 70-300 not that great, but the autofocus also occassionaly makes a loud screeching sound...not good for weddings!!! I rented a 70-200 F4L IS for the wedding last year, and absolutely loved it. It is an incredibly sharp lens. It worked great for this wedding, as it was outdoors in good light in the early afternoon. One of the upcoming weddings is indoors. I am concerned as to whether the F4L IS is going to be fast enough. I realize that F4 is not that fast for indoors work, but at the same time, there's not much subject movement indoors at a wedding, so the IS might be enough.
My other option is the Sigma 85 1.4. I have rented the Canon 85 1.2 and was blown away...however there is just no way that it is in my budget. The 85 is obviously much faster for indoor work, but is much less versatile than the 70-200.
If I get the 70-200, I will again rent the 85 1.2, and if I buy the 85 1.4, I can rent the 70-200 2.8L IS. Either way I will be covered concerning the wedding, but the question I am wondering is which of these two should I buy first!