Lens review

Tamron SP AF 17-50 mm f/2.8 XR Di II LD Aspherical (IF)

5. Chromatic aberration

Unfortunately, the Tamron 17-50 mm did not impress us in this category. Tamron’s full frame substitute – the 28-75 mm model – is equipped with three low dispersion glass elements and in its worse performance the chromatic aberrations does not exceed 0.1%. The Tamron has only one dispersion glass element and probably this causes its poor behavior, which can be observed in the diagram below.

For the most difficult combination of f/2.8 and 17 mm focal length, the chromatic aberration reaches a value of 0.15%, which is not a very impressive result. Fortunately, for all the focal lengths, stopping down the lens helps significantly. For 30 to 50 mm focal length starting from f/5.6 we are able to decrease the chromatic aberration to almost nothing.

The pictures below show the situation.