Used with a 645z, the weather sealing and light weight make this an awesome performer in inclement weather. Fantastic contrast, sharpness and bokeh.

Picture taken @ 1/1000 sec and f/8 handheld in Aperture-priority mode.

• +

  Sharp at middle apertures, splendid colors and contrast.

• -

  None when used for landscapes at middle apertures.

Spectacular lens. Extremely sharp on the Pentax 645Z, great contrast, and small footprint. Great grip. Little to no flare, even shooting directly into the sun. Only minor quibble is that there is some purple fringing against bright light. Fantastic value.

That is a wonderfully sharp prime lens! Shooting on my Pentax 645z is a dream for that innate medium formate look. I would nightly recommend this as a must have in your camera bag...

This is a really good lens. I was nervous about buying one because reviews are not unambiguously positive, and it's not spoken of much outside this forum. I'm glad I took the chance. I wanted something faster and lighter than my fantastic 45-85/4.5 SMC Pentax-A 645 zoom. This fits the bill.

• +

  Well built, reliable, sharp

• -

  A bit heavier than I'd like...

This lens can uses in Pentax 645D, I think it is a good lens, but the only thing I think it is not good enough is the depth of focus. Any way, this is a good lens I think. I like it.

its perfect for the new 645z. the weight is awesome for the quality.

I gave 8 because of the sharpness decrease at corners when I focus at infinite (see below for detail). Other than that, this lens is really good. I would recommend this lens except those who frequently focus at infinite.

• +

  Sharpness at the center

• -

  Field curvature, CAs at the corner

I chose the 55mm lens over the 45mm as it's a more suitable focal length for general use - aprox. 35mm equivalent rather than aprox. 28mm.

• +

  Well built, sharp

• -

  None

This is the standard for the Pentax 645 D. It is sharp, has good contrast, and responds quickly to the auto focus. I have not noticed the soft corners that some reviewers have mentioned. The lens hood has a panel that can be removed to access filters. This is a nice feature.