Portrait-Length Lens. With a 35mm focal length equivalent to 117mm after the sensor crop factor, the Pentax 150mm f/2.8 is a great choice for portrait use in and out of the studio. The fast f/2.8 aperture provides a very shallow depth of field and enables relatively low-light shooting.

Internal Focusing. The internal-focus design means the focusing group is much smaller and easier to move. Not only does this enable the lens barrel to stay in place while focusing, but it also increases focusing speed.

Please Note. This is a legacy lens that was originally designed for medium-format film cameras. We’ve noticed that it tends to slightly front- or back-focus, so you’ll want to make sure you microfocus adjust before you start shooting.