i want buy a lens

[pipou]

hello today i get my 20D i'am want buy one lens from this 3 lens SIGMA 18-50 or CANON 17-85 IS or SIGMA 18-125 thanks for your help

[ukexpat]

hello today i get my 20D i'am want buy one lens from this 3 lens SIGMA 18-50 or CANON 17-85 IS or SIGMA 18-125 thanks for your help

What are your usual photographic subjects? Don't forget that the crop effect of the 20D (because its sensor is smaller than a 35mm film frame) means that the effective length of those lenses has to be multiplied by 1.6...

[slug]

congrats on the 20d.
i don't have any actual experience with these lenses but i'd go with the canon 17-85 simply because it has USM and those two sigmas don't i think.
the speed and silence of USM turns me on.

they're all about equivalent on wideness which also turns me on.
i used to use mostly a canon 28-70, but after emily got a sigma 15-30mm i pretty much use that whenever possible.

second choice if you only plan on having one lens would be the sigma 18-125mm because of the longer zoom range.
unsure if the large range of zoom would have any noticeably negative impact on image quality.

note: already 1936 photos on PBase taken with the 20d. must be nice to be Canon and have people buying them as fast as they can make them.

-slug