Review of the Tamron 55-200mm f/4-5.6 LD Macro lens
That may be a negative consideration for some potential buyers but upside of this arrangement is a very wide zoom ring bearing a lovely tactile rubber grip. Similarly, the disadvantage of an externally rotating focusing movement is minimised by the relative proportions of the two rings, which reduce the chances of stray fingers obstructing the focusing ring as it rotates in AF mode.
Numerically, the Tamron 55-200mm returned some stunning MTF results at larger apertures for short-to-medium focal-length settings but displayed rapid fall-off and significantly poorer results at its 200mm setting. Although this was disappointing it has to be said that close examination of pictorial images showed them to be much more even-keeled. Importantly, however, that finding cuts both ways and the Tamron looked neither as bad nor as good in real-life as its technical figures predicted.
Curiously, the Tamron’s pictures consistently had the appearance of transparency images, looking slightly underexposed but benefiting from protected highlight detail as a result. It also has a slightly smaller zoom factor than its 55-200mm designation suggests and lacks a little at its shortest focal length: as a result the lens seems to cover a range closer to 60-200mm.