SMC Pentax-A 1:1.7 50mm

Cost: 15$ (average market price $63)

Again a very smooth, fast, prime lens from Pentax. I found this lens in a Thrift Store in North Vancouver. A true testimony you can still find great lenses for almost nothing.

The lens is Pentax smooth, but it's one of the first lenses where Pentax started to use plastic instead of metal to make the lens lighter. Especially the aperture ring feels very brittle. But it looks great on the Sony a6000. The APS-C crop factor of 1.5 results in 75mm. Decent sharpness and color rendition. Will try it soon on some portrait photography... A please to walk around with.

To combat partial reflection, Pentax developed chemical coatings for the lens surfaces with minimum light loss. SMC is "a remarkable seven-layer lens coating process that cuts the reflection ratio down to just 0.2% per lens surface. The result is a dramatic improvement in both color fidelity and brightness and the elimination of flare and ghost images."

SMC was patented and first applied in 1971, when Pentax was still making screw mount equipment. The multi-coated lens lines changed from Takumar and Super-Takumar to Super-Multi-Coated Takumar and later on to SMC Takumar. SMC Pentax was used for the newly introduced K-mount lenses. Pentax's SMC is still today considered as one of the best lens coatings on the market.

Lens Specification:

Focal Length: 50mm

Maximum Aperture: F1.7
Minimum Aperture: F22
Image Format: 35mm
Lens Mount: Pentax K
Optics: 6 elements, 5 groups
Blades: 6 blades
Focussing: Manual
Minimum Focus: 45cm
Maximum Magnification: 0.15x
Filter Size: 49mm
Weight: 165g
Length: 38mm
Production: 1984 until 1989
Serial Number: 1833185

More information on Pentax

Samples:

Sources:
Wikipedia - Pentax
Pentax Forums
All Photo Lenses