Canon EF 70-300mm Lenses

[cleverusername]

Canon has several 70-300mm lenses on this page:
Canon U.S.A. : Professional Imaging Products : Telephoto Zoom
What are the differences between the following:
EF 70-300mm f/4.5-5.6 DO IS USM $1,399
EF 70-300mm f/4-5.6 IS USM $649.99
EF 70-300mm f/4-5.6L IS USM $1,599
The specs appear very similar but the prices are quite different. Thank you for your input.

 

[Vik880]

If you cannot readily tell the difference between the three perhaps it would be best to wait on buying one. The first has "diffractive optic", the second is "basic" in regards to the other two. The third is an "L" series lense which is canons high high quality lense.

 

[Dao]

The first one (the DO lens) has special optics to make it smaller physically. But you need to pay extra for that. Otherwise, prices reflect the optical as well as the build quality of the lenses.