Lens Reviews

Lens Review: Focal MC Auto 135mm f2.8

One of the nice things about shooting with Pentax is that pretty much every lens that was made for K-mount will work on current DSLR cameras (the same can be said of M42 screw-mount with an adapter). There are probably a few exceptions, but I personally don’t know of any. This lens I’ll be looking at today is a fully manual telephoto prime lens with a large aperture. A lens with specifications like this would cost hundreds of dollars if it had auto-focus and current-day lens coating. The reality is that it’s a bargain bin lens that can be had for probably around $50. I had bought this lens quite a few years ago from expecting a “generic 135mm f2.8” lens, and that’s what I got. From what I can tell, Focal was a brand-name for K-mart or Sears and MC stands for multi-coating.

Technical specifications for the lens:
Lens Mount: K-mount
Lens Construction: black metal with rubberized focus ring
Angle of View: 18 degrees (11 degrees in APS-C)
Aperture: f2.8
Number of Diaphragm Blades: unknown
Minimum Aperture: f22
Minimum Focusing Distance: unknown
Filter Diameter: 58mm
Maximum Magnification: unknown
Dimensions: unknown
Weight: unknown
Case: none
Objective Cap: none
Hood: built-in slide out type
Lens Aperture Ring: included
Tripod Adapter: none
Diaphragm Control: manual
Focal Length: 135mm (205mm in APS-C)
Notes: none

General talk about the lens and its features:
This is a fully manual aperture and focus lens. The lens has a pretty standard focal length and maximum aperture for the time period it was made. With a maximum aperture of f2.8, you can use the lens in lower light situations without much difficulty, but is offset at times due to not having the ability to auto-focus. The lens construction is quite a bit above most lenses being produced these days as it is completely metal, the focus ring is smooth, the aperture control ring is also solid and smooth, and there is a built-in pull out metal lens hood. The lens is considerably large and heavy compared to similar models made in the same time period, but that’s probably due to its cheaper k-mart brand history.

What I like about the lens:
– Nice build quality.
– Built-in hood.
– Sharp images.
– Cheap telephoto lens.
– Large maximum aperture.

What I’m not too fond of:
– Manual focus and aperture take more effort, and the focus ring had a long range to rotate through.
– No data connection to the camera body means no focal length or aperture information stored in EXIF data. That makes it difficult to identify images taken in the past.
– Low contrast in strong sunlight.
– Prone to green/purple fringing.

Images with a bit of analysis:

The default image was pretty bland and low contrast, but that’s easily fixed:
A worst case scenario with green/purple fringing:
This lens is able to produce sharp results:
Only having manual focus available allows you to think of photos from a different point of view (foreground blur is intentional):

A few additional images:

So it it worth $50 or so? I’d say it certainly is. Good build quality and decent optics should keep these lens away from the trash bin as long as Pentax users can mount old glass. The major negatives to not buying the lens in my opinion would be the physical size of the lens as well as the substandard lens coating that tends to result in washed out images. On the flip side, it’s quite easy to modify contrast in post processing that tends to bring out vivid and sharp results. With some care, this lens can be a cost effective way to get a moderate telephoto for your Pentax camera.