Any FL range over 5x (max FL/min FL) raises a warning flag in my mind - you just know that there will be at least some optical deficiencies. The 50D and 18-200 in a Think Tank Photo Digital Holster 20 went with me everywhere and were not a burden.

If we compare the specifications of the Sigma 18-200 mm C with those of other superzooms, then the Sigma 18-200 mm C offers more close-up than the competition. The lens hood provides more help at 18mm than 200mm (a 200mm-specific hood would severely vignette at 18mm),

Sigma 18-200mm f/3.5-6.3 DC Macro OS HSM Contemporary Specifications

The focusing ring is mounted near the front of the lens, with a rubber ridged knurl that is easy to turn. The lens really isn't built for manual focus: the ring is only a quarter-inch in width, and doesn't offer much in the way of travel for manual focus operations (much less than a quarter turn). The ring turns during autofocus operation, and can't be overridden in this mode: you must specifically disable autofocus to override the focus clutch. The lens does not physically extend as fast above 135mm and the net change in angle of view from 170 to 200mm is very small.

Corner sharpness does fall off a bit in the 18-28 mm range, even stopped down, but only a bit, and contrast remains reasonably good and there is relatively little visible CA. The close focusing ability is great, and for this the fact that the maximum focal length decreases as you focus closer doesn't hurt--by the minimujm distance, field of view is about the same as a 100mm macro lens, meaning so are depth of field and perspective effects, and I like 100mm macros. This lens competes directly in the 'stabilized superzoom' market with the Nikon 18-200mm F3.5-5.6G AF-S VR DX, Canon EF-S 18-200mm F3.5-5.6 IS, and Tamron 18-270mm F3.5-6.3 Di-II VC, all of which which we've reviewed over the past year. Its main advantage at the moment is that it is considerably cheaper than any of these other lenses, making it much the most affordable option for users looking to supplement their collection with a general-purpose travel lens. But in this case, does cheaper also mean inferior, or has Sigma delivered quality on a budget? Headline features Compared to many other superzoom lenses, the Sigma 18-200mm f/3.5-6.3 DC Macro OS HSM is relatively compact. This makes it a great lens to have on your camera all the time as a walk around lens. For this test, we have paired it with the Canon EOS 750D and it works well, not overbalancing the camera at all. Certainly Canon would put their best AF system in a lens they expect to get decent image quality from - even mid-line lenses such as the Now I need to decide on some glass and I want a all-in-one type of lens to start with and while I understand that those lens come at a cost both price wise and sharpness and they will never be as good as a dedicated lens I also understand that Canon ones are better than the likes of Sigma and Tamron for this particular type of lens.I had some bad experience with superzooms before, Sigma 18-200 was very soft, Tamron had a inaccurate focus and was soft at 200mm, sold them after 200-300 pictures.