Review : Sigma DC 18-125mm 1:3.8-5.6 HSM Lens

The review lens was a rather tight fit when we mounted it on the EOS 40D body we used for most of our tests. It's slightly heavier than the kit lenses most manufacturers supply with entry- and mid-level cameras. However, when mounted, it proved a comfortable match for both the EPS 40D and the much lighter EOS 1000D (which we used for some test shots).
The HSM drive was quiet and autofocusing was fast and accurate, only slowing slightly at low light levels and with subjects where contrast was very low. Both the focusing and zoom rings moved smoothly and positively. Moving from the 18mm to the 125mm focal length requires a quarter of a turn and extends the lens barrel by just under 5 cm. Setting intermediate focal lengths was relatively easy, although the accuracy of the engraved focal lengths was not particularly high for the settings at the middle of the focal length range.
The focusing ring moves through about an eighth of a turn and feels a little slacker than the zoom ring. The degree of precision provided is not as high as we would like but adequate for most purposes.

Margaret Brown