I recently purchased a Canon 40D Kit & I am considering buying a telephoto lens. On the Camera Price Buster website the price of Canon EF70-300mm f4-5.6 IS USM is £338, however the price of Canon EF70-300mm f4.5-5.6 DO IS USM is £755 (over double the price). This price difference is reflected on other camera web sites as well. Can anyone explain why this is so. What does "DO" stand for? & is this lens really necessary? Will I be better off going for a cheaper Sigma or Tamron? ( my budget would be between both of the above prices, around £500) This lens jargon is new to me, so advice would be gratefully appreciated. Regards, Misty
Cheers Misty