Vivitar 28mm f/2.5 from Kiron

Vivitar 28mm f/2.5 from KironVivitar 28mm f/2.5 from KironI bought this Vivitar lens from a good friend of mine and I know that the K mount won't fit into the KAF2 mount in my K100D. The lens is in superb condition and inexpensive price for a dinner lure me to get this lens without a 2nd thought. And it turns out the lens, with the base (baffle) removed, I can use it on my K100D body without any noticeable problems. All that is needed is to remove three tiny screws on the lens base plate and once the baffle is off, I have no problems using the lens as is.

I later used my Christmas toy with Dremel to modify the extra flange that make the lens incompatible with my K100D body. With the Dremel tool, I manage to grind down the obstructing flange area and painted it black with a black marker.

Dremel tool to alter Vivitar 28mm f/2.5 from Kiron
Dremel tool to alter Vivitar 28mm f/2.5 from Kiron
And here are few test shots:

Vivitar 28mm f/2.8 Kiron Test shotsVivitar 28mm f/2.8 Kiron Test shots
Vivitar 28mm f/2.8 Kiron Test shots
Vivitar 28mm f/2.8 Kiron Test shots
I have not formed conclusive opinions on the lens but so far I like the fast aperture at f/2.5 and the construction of the lens from Kiron is quite solid. The focusing ring is well suited for manual focusing. Sharpness at wide open aperture is reasonable though I am not certain as I do find lack of detail in the test shots that I made with the lens. With more testing, I would need to decide if I should keep this lens or find something better such as the Pentax A 28mm f/2.8 or the Pentax F/FA 28mm f/2.8 with autofocus.

Impressions & Notes:
  • Filter size is huge, it is 67mm
  • Front element is unusually big and it is likely prone to flare and I later added in a matching lens hood.
  • The lens is an odd ball in bokeh. Sometime very nice and sometime mediocre and I thought one reason may come from flare seen in the bokeh. When flare does happens in the bokeh, it takes out the fine detail.
  • This is one of my lens with circular ringed lights in the bokeh. With the addition of lens hood, I am hoping the flare is reduced in the bokeh.
  • Manual focusing ring is smooth, precise and large over half of a circle.
  • Minimum focusing distance is small as I recall it, roughly 0.3 meter, I need to check to confirm
  • Manual focusing is best with this lens
  • Lens is well constructed and built with metal in barrel
  • I prefer this Vivitar 28mm f/2.5 from Kiron over my Pentax M 28mm f/2.8 though my preference might have changed had my Pentax M 28mm f/2.8 been free of fungus. The pentax has an edge in color when compared to the Kiron Vivitar. In terms of sharpness, build quality and focus ring design and the overall feel, my preference definitely goes to the Kiron.



john_van_v said...

Hey great test shots. I am about to bid on one just like it, but in Konica Hexar mount -- so there will be no digital testing. Hexar is just too close to the focal plane to allow for an EOS adapter.

I am curious about one thing you wrote: "and inexpensive price for a dinner lure me to get this lens"

What does that mean?

Was that the "lure dinner" in your test shot section?

Thanks in advance, John

Hin Man said...

I got the lens for a small cost like a dinner. I am likely to sell it to others in the near future. If you see this lens under $50 dollars, that would be the price that I recommend.

Unknown said...

Hi Hin!

I just ran across one of these in the local camera shop & bought it based on your review/shots. It's the screw-mount version, though. Looking forward to trying it out.

-Jay (jsherman999 @ pentaxforum)

john_van_v said...

I recenty got a rexagon 28 m42, and it seems to be similar to this lens, though I have not tested it yet.

gshin said...

luv your shots w/ the older lenses !!
I recently bought K100D Super. I have Olympus OM2 camera and lenses that i've kept, but have been collecting dust since era of digital. OM2 lenses "almost" fit into body of K100D super, but not quite.
Any suggestions to modify the lenses so that they can be used on the K100D body ?? thanks !!

Michael Zhou said...

Have you used M42 to K mount adaptor without 'modifying' the lens?

Hin Man said...

Thank you all for the visit and comments.

@Michael, the screw mount version should not have a flange like my K-mount version. No modification is needed. A m42 to K mount adapter is needed when using a M42 lens on Pentax K body.

Hin Man said...

@gshin, I don't think the OM lens can be adapted to the Pentax K bodies. Unless the mount is in M42 screw mount. As far as I know, the OM mount is not compatible to K mount without alternation and I am not aware of adapter that fits OM lens to Pentax K body.

Anonymous said...

Hey Hin Man,
Kudos to you for being one of the few to blog about this lens! I acquired one just today at ARC for $5.00, in uni screw thread mount for my Fujica, hoping against hope that it might meter wide open. It doesn't. O well. It will be a nice stop-gap for the day when I find a Fuji lens.

Just relax said...

Great test. I'm now thinking of buying such lens. What i don't like is the colors of pictures. They have very small contrast

john_van_v said...

colors: are you nuts?

Ashley Pomeroy said...

For a wide angle lens it has really nice bokeh - not totally smooth, but distinctive. And there's nothing wrong with the colours, they're lovely.

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