What zoom lens?

Have not heard good things about the 75-300mm USM III.  Pictures are really soft and it will feel cheap.

"If you care about great image quality and sharp photos, the Canon EF 75-300mm f/4-5.6 III USM Lens is not for you. And Photoshop cannot enhance details that are not there."

http://www.the-digital-picture.com/Reviews/Canon-EF-75-300mm-f-4-5.6-III-USM-Lens-Review.aspx

Just from that alone I would lean towards the 100-300mm despite the shorter zoom range and higher f-value.  If you are going to be doing most of your shooting at nearer 300mm then even more reason to get the 100-300mm because the f-values are the same and it is a much better quality lens.  At max zoom it will perform much better than the 75-300.  The £50 more it costs is worth it imho.

http://www.the-digital-picture.com/Reviews/Canon-EF-100-300mm-f-4.5-5.6-USM-Lens-Review.aspx

Of the two you are looking at certainly the 100-300mm is the better lens but it might be worth thinking about it a bit more and seeing if there are any other lenses that fit the bill.  Another option would be looking at refurbished/used lenses of a similar focal range but further up the price ladder (if they were new).

75-300mm

/thread

^ thanks, very useful insight there!

I feel like when it comes to lenses and glass, you get what you pay for and going cheap isn't always the best strategy.

I am thinking of extending my budget and getting the CANON 70-200 f4L USM LENS instead.

When I was thinking of different lenses/buying one used/refurbished.  That was one of the ones I was thinking of (any one of the 70-200mm L's).  It should work perfectly for what you want and I'm sure you will enjoy using it.

definitely drop the extra money for a 70-200 f4L, you'll be much happier in the long run. Weather resistant body, f/4 aperture through the whole range, USM, Full Time Focusing, Excellent optics, etc. etc. etc.

Probably the way to go if you can. I was going to go that route but then went with a Sigma 70-200 F2.8, I needed the faster aperture so I could get a shallower DOF. I shoot video with it, not really stills, but the few stills I have shot with it seemed great, so if you were looking at that lens at all I can tell you that I am happy with it. But there is no doubt that L series glass is better.

I fully agree. Those lenses that you are looking at will not come close to the optical and build quality of the 70-200. Do you really need to have a 300 lens? on a cropped sensor the 70-200 will reach pretty far. I have used the nikon 80-200 (older version) for shooting soccer and football (when i can get to the field) and 200 is plenty. I am soon going to pick up a nikon 70-200 because i loved it so much.