Cheap Lense

I am a newbie to this photography, I am shooting a Highschool football game with low lights, I only have a Tamron ap 75-300m 1:4-5.6 ld. Aperture doesnt go lower than 4.0. What kind of setting should I have on my canon 20d with this lense? I know I need a faster lense with a bigger aperture setting, but I am on a budget right now. Any suggestions are welcome! Thanks PJ

crank up the ISO to 800, 1600, 3200 take a few shots to see what works best, you may be able to get away with 1600 depending how bad the lighting is.

I also have a 580 speedflash, absolutely dont know how to run it yet.

depending on field you mihgt not have enough light even with ISO1600 or 3200 to stop the action and get good pics., I use 2.8 and sometimes even 1600 no enough, but with 2.8 it is fixable in PS.

since you have flash, try to use highsync and shutter speed no less then 1/350, I'm personally don't like anything below 1/500.. one thing, be really to have lots of batteries with you for flash.

What mode should I be in on my canon 20d that works the best, again I am new at this I apologize! Thanks

I'll be doing the exact same thing with operation equipment, shooting for a pro, so don't be ashamed of your equipment. Shoot at IS0 1600 Manual. Shutter speed 1/250.If I rember right, the 580 EX I use is set at ETTL. Don't be afraid to use the 5 FPS! .. Even 2.8 is a little slow for High school. If you want a faster lens, get a 50mm 1.8.... Football will be ending next week, it works great for basketball.. Again, make sure you bring extra batteries... Get some rechargebles to save money to buy some L glass, it adds up

If you put it in sports mode, it will slow the shutter etc.. etc. etc.. Sports mode is great when it's out in the day time though....

most HS football games have pretty crummy lighting, a min of iso1600 @ 2.8 is pretty normal

in these uneven lighting situations, i find it best to show up early, meter zones on the field, and shoot on M, you're not going to be adjusting aperture at all, and you'll be struggling to get the highest shutter speed possible. M is by far the best choice for crummy outdoor night football games, Av can work, but the 20d starts tripping out sometimes, and in harsh light you'll lose shutter speed a lot, and on Tv you'll end up with totally under exposed stuff