Pentax 35-70 lens test
Zoom lenses that offered commonly used focal lengths of around 35-70mm were prevalent in the latter days of manual focus film SLR’s Pentax Lens tests Macro Zooms. The quality though varied greatly so without actually trying them its hard to say how well they will perform. With this in mind I mounted my recently acquired Pentax A 35-70 f4 on a Pentax ME Super with a roll of expired Kodak 400. As you would expect the film is grainy but that doesn’t detract from the intent which is to test the lens. What I am looking for is sharpness across the frame and how much chromatic aberrations it creates as well as the more subjective ‘rendering of out of focus areas’. In all three this lens exceeded my expectations. Even with the aperture wide open the sharpness continues from the center all the way into the corners. There was hardly a hint of any fringing or chromatic aberration although a tougher test on a more demanding digital camera might turn up some I suspect as seen bellow. If you look around the edge of the white petals you will see the softness and fringing of this digital shot at f4.0 that said that goes away by f5.6. I would say this is optically the best SMC A zoom lens in this general focal range that I have come across for use on a digital camera.
And finally the out of focus or ‘bokeh’ areas of the image have nice smooth transitions that add to the three dimensionality. It’s also a very compact lens that isn’t much larger than a prime lens however the main compromise with this lens is the rather slow maximum aperture of f4.
