Do a lot of outdoor activities and changing lens is a real pain. I bought this lens because in the midst of changing a lens I would often miss the shot. That's the real issue because getting the photo trumps the pixel perfect image quality. Sure spending $10000 on great lenses will get the quality.

Great all purpose lens

Not weatherproof

I have had this lens on my XTI for about 4 months. I am not sure about all the photo terminology, but I can tell you the following: If you are taking shots of people, MAKE SURE YOU HAVE A LOT OF LIGHT. Otherwise, the picture will not be sharp.

Zoom range

Difficult to obtain SHARP shots

If you are on a budget and you are looking to add a new lens to your SLR

Although this is a nice lens, I'm disappointed that the one I received is less than stellar as it has quite a bit of dust inside as well as it tends to "vibrate" at times when you press the shutter button half way down. Am hoping that this company does the right thing & correct the issue.

Epinions doesn't allow embedded photos, which is a shame for camera/lens reviews where the photo is

Small, compact; Good optics for such a wide range

Soft corners at 18mm wide open; Canon version must be focused parfocally above 135mm

Great lens, focus and aim is great. A little noisy at times & doesn't perform well in the heat struggles to focus a bit but nothing a little flick off of the power button can't handle. Good quality well made and has taken some amazing pictures at close and long range

Can anyone compare Canon EF 28-135 IS USM to Sigma 18-200 DC OS pls. Equivalent IS and sharpness

An all-in-one superzoom lens with optical stabilisation for APS-C digital SLRs which prides a range equivalent to 27-300mm on a 35mm camera.

High zoom range; Decent sharpness at shorter focal lengths; Highly effective optical stabiliser; Price

Falloff in sharpness at 200mm; CA towards edges can be noticeable along high contrast edges; Slow AF at telephoto end

One of the limitations with a kit lens is that you don't have a great focal length range, especially at the telephoto end of the scale. This Sigma 18-200mm f/3.5-6.3 is not only small and light but also has an impressive optical stabiliser built-in (Canon and Nikon fits).

I can't write a review about this lens because it didn't fit my camera. it needed an adapter. Make sure you ask questions before buying I didn't ask had to find out the hard way. there are adapters that will fit the lens.