Sigma 100-200mm Zoom K M42 lens on Sony Nex 6

I received this Sigma 100-200mm Zoom K lens as part of a camera bundle on ebay when I purchased a Praktica Nova 1B 35mm slr a few months ago. Since the whole bundle of camera + std lens and this lens in a custom made leather case were all bought for £10 it was quite a bargain, but to buy one on it’s own would probably cost no more than about £20.

Images of Sigma 100-200mm Zoom K lens

Sigma 100-200mm Zoom K Description

The lens has a slightly odd focal length range of 100 to 200 mm. At the time this lens was made (late 1970’s – early 1980’s) the standard telephoto zoom range offered by most manufacturers was 70 to 210, so this is slightly reduced from that, but has the advantages of a constant maximum aperture of f/4.5 and a macro facility.

It is a long lens to mount on the camera, especially a camera as light and thin as the Nex, and it feels quite heavy, but it is mostly made of metal so that isn’t really a surprise. The mount is M42 (marked as ‘for Praktica’) and it has an inbuilt lens hood which pulls out to shield the front of the lens. There is no Auto/Manual switch on the lens, but the pin which controls the aperture is automatically pushed in using the M42 to Nex adapter.

The zoom operation is carried out by pushing the barrel of the lens in and out, whilst the focus is a rubber coated large band around the body of the lens. I found the operation very smooth – damped just enough to make it easy to use and although there was a hint of focus creep if the lens was held pointing downwards, in real use this wasn’t a problem.  The macro facility is engaged using a separate lockable ring at the bottom end of the lens, just in front of the aperture. There is a push button to allow it to be turned and it has markings to suggest magnification ratios of between 1:9 to 1:4.5. In use I found that it certainly reduced the minimum focus distance quite considerably. I was able to focus about 2 1/2 feet away at 200mm and down to about 10 inches at 100mm.

The condition of my copy of the lens is very good. There are no scratches or discolouration in the glass, and apart from a few very light dust particles in the bottom section of the optics it is mark free. Most old lenses get some amount of dust, particularly zoom lenses, but this one seems pretty clean.

  • Focal length range 100 – 200mm (150 – 300mm equivalent on Sony crop sensor)
  • Aperture range f/4.5 to f/22.
  • M42 fit (other mounts were also made)
  • Macro focus
  • Push to zoom

Sigma 100-200 Zoom K Sample images

I went out with the lens attached to my Sony Nex 6 to get some sample shots this morning. There has been snow overnight so I dialled in a one stop compensation to allow for the extra brightness the snow adds and which would otherwise lead to a greying of all the images. Most of these were taken around the f/8 to f/16 range and I’ve included the camera jpegs and some Lightroom images processed from the raw shots.

To view the shots use the galleries below.

I think they show the lens is a capable if not stellar performer, and has enough range to cover short to medium telephoto usage. The macro facility is certainly useful and enables pretty good macro shots.

From camera Jpeg images

Lightroom processed images

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