Here we have the third 55-300mm lens from Pentax, covering the APS-C format, which equates to a “35mm equivalent” of 84.5-460mm. This is also the third Pentax lens to offer a retractable construction, making the barrel shorter for carrying and storage. (The first two were the Q series 15-45mm zoom and the 18-50mm that came with the Pentax K-S2 body.) This time we have a new optical formula and the first Pentax lens with an electromagnetic diaphragm. This results in a new variant of the lens mount designated KAF4. This has other implications, as we shall see. So let’s delve under the surface and look at the details of this new optic.

Handling and Features

The overall appearance and feel are quite similar to the 18-50mm retractable lens that we have already seen. A single easily operated button releases the lens barrel so that the zoom ring can be used. If the camera is switched on whilst the lens is retracted, the shutter release is disabled and a warning message appears on the rear screen.
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