I recently have a Canon Digital Rebel XT. I use a Sigma 28-300 mm lens and a canon speedlite 430ex flash. Is there anyway I can take pictures at a high school football game with lights at night without using a flash from the sidelines? I up for buying a lens if necessary, but I would want that lens to also be able to take nice pictures of the outfield at baseball if possible. Any suggestions would be appreciated. Thanks much... :)