Playing With Lenses: Unknown for a reason: Lenmar 28mm 1:2.8 MC

Cost: 7.99$ (average market price unknown)

As they say, it's hard to screw up a prime lens... And this lens is the exception. Not sharp at all, especially in the corners, creating a soft feel to the pictures. Some chromatic aberration and easy to over-expose highlights. I also did not like the color, resulting in washed out, blue-ish, pictures.

The lens does feel solid, is good looking, has an all-metal build and has some real smooth focussing , almost like a older Pentax lens. But image quality is so low, that it outweighs the looks and build. Maybe I just have a bad copy...

I don't believe I will keep this lens in my collection. I have way better 28mm lenses and I don't believe it has any collector value.

Lens Specification:
Focal Length: 28mm
Maximum Aperture: F2.8
Minimum Aperture: F16
Image Format: 35mm
Lens Mount: Pentax PK
Optics: Unknown
Blades: Unknown
Focussing: Manual
Minimum Focus: just under 150cm
Filter Size: 55mm
Weight: 229g
Length: 48mm
Production: 1970's
Serial Number: 28505
Made in: Unknown

Company:

Lenmar was a rather unknown American electronics supplier to stores such as Best Buy, etc... Not sure if it is related to the present company under that name. They re-badged mostly low-quality lenses and don't seem to have a good reputation for their lenses.

MC
MC, or Multi Coated, stands for a multiple of chemical coatings for lens surfaces with minimum light loss. The result is a dramatic improvement in both color fidelity and brightness and the elimination of flare and ghost images.

Adapter:

Lens Turbo II PK - Nex

Cost: $75, used on B&H PhotoVideo, new for $149

The Pentax K Lens to Sony E-Mount Camera Lens Turbo Adapter Mark II from Mitakon allows Pentax K lenses to be mounted on Sony E-Mount APS-C format cameras, increasing the angle of view by 0.726x and the maximum aperture of the lens by 1 f-stop.The four optical elements of the Lens Turbo adapter condense light from the Pentax K full frame lens and project it onto the camera's APS-C sensor allowing the sensor to capture all of the lens' transmitted light, negating the 1.5x crop factor and effectively producing full-frame coverage on non-full-frame sensors. A corresponding increase in the maximum aperture of 1 f-stop makes the lens more effective in low-light situations.

The Mark II version of the Lens Turbo features an improved design to produce sharper images. Its rectangular rear lens rests closer to the camera's sensor improving light transmission and an enhanced lens coating minimizes ghosting and flare. One extra-low dispersion (ED) lens element reduces aberrations for better delineated images. The adapter offers a sturdy metal construction and stainless steel mounts, it attaches to both camera and lens with little play and includes a front and rear protective cap. The Lens Turbo is a manual adapter offering no electronic communication between lens and camera.

Samples: