I have a canon rebel xt with several lenses. I have a standard 35-80 lens, a 75-300 1.5 lens and just purchased a 70-200 1:2.8 lens. I was told this would allow for better footbal pictures at night from the sidelines. The camera shop said to use the sport setting but I am still getting a lot of blurring. I must need to adjust elsewhere.. . HELP

Shooting sports in low light is one of the most difficult photography challenges. You need to do a lot more than just put your camera in "sports mode".

1) You need to shoot in RAW. This is because you will likely need to under expose 1-2 stops to get a fast enough shutter, or will have to use a very high ISO, and with either of these you need the RAW file so you can process it to minimize these issues to get good images. After you copy the RAW files to your computer use a RAW converter (available in the software that came with your camera, also available in Photoshop using the Adobe Raw converter, or in Photoshop Lightroom, etc.) to process the file, and in the raw conversion you will adjust the exposure reduce the luminance and color noise, as well as make any other adjustments needed before you convert the file to a tiff or jpeg.

2) Set your camera at the highest ISO it can use. I don't know off-hand what the top ISO is for the XT - it may be 1600 or it may be 3200. When you manually set the ISO it will top out at one of those numbers, and then there's one more setting called H or High. The H or High setting is pretty bad, avoid using it. Start with the highest number setting. After you take a few test shots if you have plenty of light (enough to get 1/1000 at f/2.8) you may want to drop the ISO down a notch. In low light situations do NOT use fractional ISO settings, only use the ones that are a multiple of 2, e.g. ISO 200, 400, 800, 1600, 3200. So to go "down a notch" from 3200, you go to 1600.

3) Set your camera in AV mode and set the lens aperture to f/2.8. This will allow your camera to select the fastest shutter possible, using the widest aperture this lens offers, and at your highest usable ISO.

Take a test shot and see what shutter speed you get. If the shutter is slower than 1/400, you need to use exposure compensation to under-expose. Try -1 EV (exposure value aka exposure compensation) and take another test shot. It will come out a bit dark, but you will get 1 stop faster on the shutter, e.g. instead of f/2.8 @ 1/200 you can get f/2.8 @ 1/400.

Once you find the right exposure, change to Manual mode and dial in the shutter and f-stop so that it doesn't change if the background gets brighter or dimmer compared to the players. Otherwise, when the players are in front of a "darker" background the camera will try to balance the light to the sensor by using a slower shutter (allowing more light to come in) and the players will be both over exposed, and blurry.

As you take your practice shots (while you are in AV mode, before you go to Manual Mode), notice if there's a lot of light variability across the field by checking to see if the camera is selecting a wide range of shutter speeds. If so, look for the areas of the field where you have enough light to get the faster shutters speeds. You may need to set your camera to properly expose the shots in those "brighter" areas and then wait to shoot when the action is happening in the brighter sections of the field.

Ideally you want a really fast shutter, 1/600 to 1/800 but this is usually not obtainable at night games. Pro photographers sometimes get faster shutters by mounting numerous expensive strobe lights all around the field so that the strobes flash and provide extra light to allow them to capture the shot, obviously this access is not available to anyone except the top pros.

Good luck!

Sorry, about the double post !