What lens should I use? - 1

My friend is getting married but can't afford a photographer and asked me to take some pictures for her. The wedding will be in a lower lit church and the reception will be in a low lit basement and I want to give the best possible pictures I can but am unsure if my lens will work or not. I have a tamron 18-270. My aperture starts at 3.4. I don't have the money to go buy equipment or anything but just wanted to see if I needed to hunt around for a good deal on a lens that would work better. I have a Nikon D3000 camera. Just wanting her day to be as good with pictures she can cherish.

Can you rent one or two lenses? If you can't, use flash or speed light.
its not your tamron couldn't work, but in low light situation like that, you need a bigger aperture than 3.5
i'd suggest using f/2.8 lenses and above.

Consider that if she can't afford a photographer, it probably isn't all that important to her. The D3000 is a bottom end dslr with a sensor that stinks in low light with any lens. It's great that you want to help out and take some shots, but don't have the expectation that you could replace a professional by having a nicer lens. Having said that, the 50mm 1.8 is a cheap lens, but I'm pretty sure it won't autofocus on walmart cameras. Still, at $125, you won't find a better lens for the money.

http://www.bhphotovideo.com/..._50mm.html