Some walk-about test shots from a Sigma 28mm 1:1.8 II Aspherical (Manual Focus) lens for Pentax KA mount on a Pentax 10MP APS-C sensor.
This lens has a very fast maximum aperture of f/1.8. On the Pentax bodies, the aperture actual registers as f/1.7. The 7-blade diaphragm produces very soft and pleasing bokeh (out-of-focus areas) at the wider apertures.
The images from the lens appear sharp, but the contrast is not very high. It benefits from a healthy dose of contrast during post-processing. The images also sharpen up well.
© David Anthony