Komura 100mm/f1.8 trouble

sorins · Joined: 29 Jul 2015 Posts: 2

Hello,

I just purchased on ebay a nice Komura 100m/1.8, described as for Pentax, M42, with 2x-3x TC and Canon fd adapter
The problem is that actually there is no M42 nor K mount (for Pentax) there, but just the TC and Canon adapter.
When I unscrewed the TC and adapter there is a M48 mount, or (as per recent info I got) is possible to be Komura specific Unidapter mount, I really don't know how this differs from a possible M48 (I measured that 48mm)
I don't want to discuss the selling/buying issue, I just want to keep this lens, but how should I fix it to match on my Pentax K3?
I have a M42 to K adapter, in case this helps, what do you suggest and, more important, for each solution, what will be the effects, in terms of focusing to infinity and the registry modification?
Thank you so much for some help!

Attila · Expire: 2025-11-18

Very rare lens, congrats! Do you have any skilled repair man near by you ? He able to solve your problem quickly to make a proper adapter to your Pentax.

iangreenhalgh1 · Expire: 2014-01-07

Sounds like you need to find another Komura lens that has that M48 fitting and either Pentax K or M42 on the other end.

John Shriver · Joined: 24 Dec 2009 Posts: 192

The Komura 135/2.8 and 135/3.5 Unidapter lenses are common and cheap. Find one with M42 (labeled "CS") mount on it. Yeah, it will take months on eBay. (Might go faster on Yahoo Auctions Japan, but you'll need a local helper service to pay and ship.)

Or, if you are in a hurry, I'm sure S. K. Grimes can machine you one.

Oldhand · Posted: Thu Jul 30, 2015 2:08 am Post subject:

I have this and am unlikely to use it. It is yours if you want it.
It has an M42 male thread and is unthreaded on the inside but held in place on the lens by three grub screws.
The inside diameter is 48mm by my ruler.
OH

luisalegria · Expire: 2018-01-18

I have a Nikon Komura Unidapter (the 48mm screw adapter) which will probably fit your lens.
It comes with a Komura 135/2.8 with unfortunately some internal haze.

I also have another rather nice Komura 135/2.8 with an M42 Unidapter - exactly what you want I think - with slight internal haze.
Only problem is the Unidapter is very tight and I have not tried to loosen it out of concern for the lens.

If you think these may be useful to you contact me privately.

sorins · Joined: 29 Jul 2015 Posts: 2

Thank you all for replies and suggestions.
It seems Internet (ebay or else) is the right place to find the solution.
Oldhand, thank you, but really I do not trust in just 3 screws to securely hold everything in place
Another solution would be indeed to machine one of that, I was just concerned about what effects will bring such adapter (whatever type) to the image and to focus on infinity.

John Shriver · Joined: 24 Dec 2009 Posts: 192

I think this auction http://www.ebay.com/itm/Fujica-ST801-35mm-Camera-LED-135mm-Sankyo-1-2-8-f2-8-lens-Manual-Focus-Exakta-/221843772950?hash=item33a6eb5616 is a Komura Unidapter lens with an M42 Unidapter, since it's mounted on an M42 Fujica ST801.

John Shriver · Joined: 24 Dec 2009 Posts: 192

This auction http://www.ebay.com/itm/Komura-Sankyo-Kohki-200mm-f3-5-manual-focus-lens-w-M42-screw-mount-shade-caps-/301702188752?hash=item463eda0ed0 definitely has an M42 Unidapter included!