Lens review

Pentax smc DA* 55 mm f/1.4 SDM

3. Build quality

Looking at DA* 1.4/55 from the lens mount we find a solid and metal bayonet, inside which there’s a stationary rear lens that doesn’t change position when focusing. Then, on the lens body, we can see a legible distance scale, located behind a pane of glass, expressed in feet and meters. On the left side of it there’s a switch for autofocus mode (AF/MF). Next there’s a convenient , big, rubbery manual focusing ring that allows very precise work. It permits us to make adjustments both in AF and MF mode.

Rotating the focusing ring causes the front system of lenses, which is maximally protruding for minimum focusing distance, to move. It doesn’t jut out over the body of the lens and has a non-rotating filter mount of 58mm diameter.

In the interest of having a strong, sealed body and a supersonic SDM motor, the new Pentax is larger than other 1.4/50 primes. However, it’s still slightly smaller than Canon 1.4/50 and significantly  smaller than the new Sigma of the same parameters. The picture below shows the Pentax standing between a multi-purpose Sigma 17-70 and Sony 1.4/50.

This table shows the comparison of Pentax parameters with f/1.4, 50mm focal length lenses equipped with supersonic autofocus motor. That table, on the other hand, with the ones deprived of it.

Inside the lens we find 9 lenses set in 8 groups. It’s the most complicated system of all 50s mentioned above. It’s even more interesting, as DA* 1.4/55 is the only lens designed for small APS-C sensors, while the others can operate with a full frame. There are also 9 diaphragm blades to form the minimal aperture of f/22, to complete the picture.

A buyer gets two caps, a lens hood and a black casing as supplied accessories.