Kenlock Auto S 135mm f/2.8

Manufacturer: Kenlock
Model: ?
Focal length: 135mm
Aperture range: f/2.8-22
Filter size: 58mm ?
Weight: 377g
Length at ∞ (M42 mount): 86mm
Lens hood: ?
Minimal focus distance: 1.8m (6ft)
Serial tested lens: 397228

The lens tested is a Kenlock Auto S 135mm f/2.8 with M42 screw mount. The lens was mounted on a Pentax K100D digital camera with the Pentax mount Adapter K (#30120) and photographs were shot in RAW mode. There has been no digital post-processing other than resizing and saving as 8-bit jpeg. Test shots were made on a cloudy day. All photographs taken hand-held with camera built-in shake reduction enabled.

The lens is an all-metal construction and has a solid feeling. I estimate the filter size to be 58mm (I have no lens of which I'm sure it has a 58mm filter size to compare with). Aperture markings are f/2.8, 4, 5.6, 8, 11, 16 and 22. These are also the only aperture settings that can be used. The lens focusses from 1.8m to infinity; focussing goes very smoothly. There also is an extra mark for infrared focussing (orange R). Aperture can be both A(utomatic) and M(anual) mode. I don't know whether there also has been a specially designed hood for this lens. It should be a screw-in type.

The diaphragm has six blades (see also picture below). When looking at the glass, I have the impression that a coating layer has been applied at both the front and the rear glass.

Kenlock 135mm f/2.8