Looking to find what kind of lens I need for low light indoor photography on a Canon digital rebel. I currently have a Tamron XR 28 – 300mm 1 3.5-6.3 macro 62. I takes great out door pictures, but indoors tends to blur. I have a Speedlite 420 EX flash, but when I use it a bad shadow is cast behind the subject, or at a distance the light of course never gets there. I realize the lens I am talking about will be expensive, but I just don’t know where to start to find what I want/ need. I really don’t have much of an understanding of f stops, etc. Examples of lens models that fit what I am asking for would be appreciated. Wheather Canon, Tamron, Sigma, or others are ok. Of course ouside photography in full sun is no problem at all with this lens at any distance. — Indoors I am mostly shooting weddings, dance recitals, children’s programs at school, etc. Thanks for your help in advance.