Lens advise

Hi, all... I've been lurking on the site for a few weeks now. What a great place this is.

Anyway, hopefully this isn't exactly a "which lens should I buy question". I am currently shooting with a 300D, with a Canon 75-300 mm f/4.0-5.6 III USM. I am trying to get good photos of my son playing football. Thus far, I have been unsuccessful. Most of the shots are blurry. I am just starting to learn to use the creative modes of the camera. I realize that a lot of my problem lies within myself and the camera.

Nevertheless, I think a lense upgrade would help as well, as my lens appears to be pretty much the bottom of the line. I am interested in 2 lenses, the Canon 70-300 mm EF f/4-5.6 IS USM and theCanon 70-200 mm EF F4 L USM. Mostly, I am interested in these two lenses because they are at the limit of what I want to spend for a lens.

So I guess my main question is, which of these two lenses will better suit the needs of a "developing" photography hobbiest, and I use "developing" loosely, as I have a long way to go. Which is more important, having an L series lens, or having Image Stablizing?

Or, am I being completely unrealistic about getting good action photos with my 300D and a lens in the $600-800 price range?

Thanks in advance for any advice and thanks for a great place to learn.

Is the canon 70-200 going to give you enough reach verses the 70-300? Are you mainly shooting daytime or at night? If at night you may want to look at the sigma 70-200 f/2.8. You could get a used one dg for about 650 or the newer one for a little more. This lens could help you get a higher shutter speed in lower light to cut down on blur. If you are shooting your 75-300 and are getting blur you can try raising the iso up to 800 or even try 1600.

Most likely, the cause of the blurry photos is a slow shutter speed that fails to freeze the action. In order to increase shutter speed and maintain proper exposure, you will need either wider aperture, higher ISO, or both. The more knowledgeable members here will be better able to diagnose your problem and recommend solutions if you post examples of your photos. The 70-300 is not likely to solve your problem as it has the same aperture profile as your current lens. The 70-200, being one stop faster will result in some improvement, but perhaps, not enough. In addition, you will lose 100mm of reach.

Finally, welcome to POTN.