At 13.8X, this digital-only 29-400mm equivalent (on DSLRs with 1.6X lens factors) offers the broadest zoom range of any Sigma lens. Joining Sigma's first digital-only superzoom of 2004, the 18-200mm, this $530 (street) lens adds optical stabilization (OS), four elements of super-low-dispersion glass...

The new Sigma 18-250mm F3.5-6.3 DC Macro OS HSM differs from Sigma's earlier 18-250mm F3.5-6.3 DC OS HSM lens in that it's physically smaller and lighter, it has better macro capability and it uses sigma's TSC (thermally stable composite) material which minimizes the effect of temperature on the...

TSC, which is incorporated into the lens barrel and is often compared to polycarbonate, has a high degree of elasticity and exhibits little variation in its structure in extreme temperature conditions.

Huge 13.9x focal length range, ideal general purpose and travel lens; Good image quality in the wide to short telephoto range; Fast, quiet autofocus; Low distortion (for a superzoom); Good build quality, smooth zooming action and no zoom creep;

Very inconsistent sharpness through the zoom range - extremely soft at 135mm; Soft corners at almost all focal lengths; Image stabilization not as effective as on similar lenses, especially at telephoto end;