For anyone who owns a Pentax DSLR there are a whole host of K-Mount lenses available to use on it dating from the very first Pentax cameras to use the K-Mount, as well as lots of third party lenses which were also made with this almost universal lens mount.
I have used several of these lenses and published the results on this site, but they have mostly been manual focus, prime lenses. I thought it would be interesting to see how well one of the more modern, autofocus lenses performed, so today I took a walk around Stevenage old town with a Pentax 28 to 90mm zoom lens from the MZ range and these are some of the pictures I took.
Just to be accurate, the lens I used is officially designated the SMC Pentax FA 3.5-5.6 28-90mm Zoom. It is a plastic construction lens, including a plastic mount, and was the kit lens on many of the Pentax 35mm autofocus film cameras of the late 1990s – the MZ range. The autofocus is driven by the camera’s focus motor via a screw thread and the aperture can set with either the aperture ring on the back of the lens, or via the camera’s aperture controls when the lens is set to A.
The maximum aperture of f/3.5 to f/5.6 means it is pretty slow and so is not ideal for dull winter days, but being of plastic construction the lens is very light weight so at least has that plus point.
Although I could use the lens on my mirror-less Fuji X-T1, I wanted to see how it performed on a Pentax DSLR, so for the purpose of this article I attached the Pentax 28 to 90mm zoom to my Pentax K5. Although the K5 is now a somewhat aged DSLR camera, it is still in my opinion a capable performer and should provide a useful guide to how well the lens will perform on any of the Pentax crop sensor cameras – although not, of course, the full frame K1.
On the APS-C, crop sensor K5, the focal length of the lens is the equivalent of 42mm to 135mm which equates to a slightly wide angle to medium telephoto lens. For the pictures below I used the Aperture Priority exposure mode on the K5 and switched on autofocus.
Pentax 28 to 90mm zoom samples
The pictures are shown in the gallery below. It was a bitterly cold day today and I ended up with my fingers so cold that I didn’t pay as much attention to taking pictures as I normally would. After about 30 minutes, I retired to the Costa in the old town for a warm cup of coffee! These pictures are not photographically very special but I think they do show that if you want a general purpose zoom lens for your Pentax DSLR, the SMC 28 to 90 is a fairly cheap option which gives acceptable results.
I suspect that when used in bright conditions where it can be stopped down a couple of stops, it would be a reasonably capable performer.