250mm IS or 300mm Mk III?

[Mattfeliks]

Hi all,

I recently bought a EOS 450D and am really enjoying it. However, I'm beginning to feel the limitations of the kit lens, so I want to splash out for a telephoto. I don't have more than £200 to spend, so I was thinking about the 55-250mm IS or the 75-300mm III USM. I'm told the IS gives an advantage of four stops-- does anyone think this is true?

I'm going travelling soon so would like something good for the road. Since I'll be on trains a lot should I forget the extra focal length of the 300 and go for the IS instead? And where would be a good place to buy?

Cheers for your help

mf

PS- this may sound like a silly question, but since my canon takes ef-s lenses, will it also be backwards compatible with the ef lenses? I just want to make sure

 

[Mattfeliks]

Nevermind, I just got the 250mm IS - didn't want to miss out on the stock. Question about the four stops with IS still stands though, if anyone has any thoughts

 

[dfrear]

Your camera will be compatible with EF lenses, yes. It can just about pull off 4 stops, but I'd say around 3 on average - it all depends on the conditions and how well you can hand hold to start with.

 

[Vertigo1]

Don't doubt the four stops claim myself. The IS on my 70-200 is also the new four stop version and its ability to stabilise the image is truly astonishing.