This lens - despite it’s large extension when zoomed out - feels and looks very well made. As an all in one lens with a film camera the range is ideal, running from reasonably wide angle, to long telephoto, but with all DSLR’s other than the Canon 5D or 1Ds the range becomes standard to long telephoto - equivalent to roughly 42-450mm. Not quite so useful but still a good all round lens. For most other digital SLR cameras, the Tamron 18-250 is what you really want, giving a true wide angle to long telephoto range in one lens. Tamron lenses in general seem to have less compatability problems than Sigma lenses with DSLR’s and I had no problems using the Tamron 28-300 on my Fuji or Nikon camera bodies.

Any lens with this wide a range is a compromise. It’s an unfortunate optical fact that, in general with zoom lenses - the wider the range the lower the performance - both in terms of sharpness and distortion. Usually you can expect poor corner sharpness and a fair amount of vignetting at either end of the focal length scale. Modern techniques have gone a long way to at least reducing these problems and the LD in this lens’s name means it has a some low dispersion elements in the design to combat these problems.

I bought this lens to use on a holiday - I didn’t want to carry lots of heavy expensive glass around - and that, I’m sure, is the reason most people will buy something like this. How did it perform? The answer is better than I expected - especially at the wide end of the zoom range.