Pentax SMC DA 50mm F1.8 Lens For K Mount 
The Pentax SMC DA 50mm F1.8 Lens For K Mount  is a fast f/1.8 lens for cameras with a Pentax K mount. Mounted to a camera with an APS-C sensor, gives an angle of view equivalent to a 76.5mm telephoto lens--ideal for portraits.
Very fast f/1.8 maximum aperture is ideal for low light situations and produces pleasing bokeh in the out-of-focus areas of a photograph This lightweight (4.3 oz) lens is very compact--just 1.5" (3.8 cm) long. The wide f/1.8 aperture makes this an essential lens for working in low light.
Designed for exclusive use with PENTAX K-mount interchangeable-lens digital cameras, this unifocal, medium-telephoto lens features a large maximum aperture and a round diaphragm to produce a natural, beautiful bokeh (out-of-focus) effect, making it ideal for portraits and casual snapshots. Its outstanding performance and compact, lightweight design also make it handy for photographers of all levels — from interchangeable-lens digital camera beginners to discerning, experienced photographers.
The addition of Pentax Super Protect (SP) coating to the lens helps prevent dust, water, grease and other substances from attaching themselves to a lens and degrading image quality.
76.5mm telephoto equivalent in APS-C format
The lens is treated with the Pentax's original SP (Super Protect) coating, which repels dust, water, grease, and other substances that may adhere to the surface of the lens. The protective coating promotes trouble-free use in all kinds of shooting situations.
- Very Fast f/1.8 Maximum Aperture
- Excellent Low-Light Lens
- Pleasing Bokeh (Out-of-Focus Areas)
- Rounded diaphragm for beautiful bokeh
- For APS-C Digital K-Mount Cameras
- Super multi coated elements increases transmittance
- 'Super Protection' lens coating repels water and dust
- Quick-shift focus system speeds focus control
- Compact and light weight design