[Help] Find a PK or M42 adapter for a lens

dancheng · Joined: 28 May 2008 Posts: 7

Hi,

I have bought a Seikanon 500mm/f8 mirror lens from eBay.
Its mount is neither PK nor M42.
Need forum members' help to identify what adapter it is?

(a) Lens with the adapter

(b) Lens with the adapter detached after loosening 3 screws
NOTE: Can see the lens mount has no thread but sloping non-cylindrically like a rocket nozzle

(c) The non-PK and non-M42 adapter with "M7000 Japan" marking
NOTE:Can see the 3 screws for attaching the adapter to the lens

(d) Closer look of the adapter attached to the lens but with the screws loosen
Note: Can see 2 screws on the left and right of the adapter
Note: The "M 7000 Japan" marking in picture (c) above now faces the lens bottom rim and becomes hidden

(e) Closer look of the lens without the adapter
Note: Can see the lens mount has no thread but sloping non-cylindrically like a rocket nozzle

This is not a T-mount, nor an Adaptall adapter.
What type of adapter is it?
Need to know the adapter-type before searching for a PK or M42 mount of this adapter-type so that the lens can be used on my Pentax k10d.
Please help. Many Thanks!

Attila · Expire: 2021-11-18

Perhaps SIGMA YS , very similar to T-mount , but bit different.

montecarlo · Joined: 04 Apr 2007 Posts: 1865 Location: Romania

Or could be similar with a russian A-mount (a some sort of half T2 mount) : http://forum.mflenses.com/soviet-lens-a-mount-t4491.html
If you have a T2 mount (K Pentax,M42 doesn't matter) and if you take out of it the inner ring, can you mount it on the lens (and fix in with the three screws) ?

dickb · Joined: 04 Apr 2008 Posts: 821

Are you sure the remaining nozzle shape can't be removed? If the bayonet mount is fixed with the three screws, is it impossible to unscrew the total mount? It does resemble a half-removed T2 mount.

My guess is the bayonet is the Minolta A (autofocus) mount, and M7000 stands for Minolta 7000 (the first camera with the autofocus mount).

luisalegria · Expire: 2018-01-18

I concur, it does look just like the inner ring of a t mount left on.

dancheng · Joined: 28 May 2008 Posts: 7

Thanks guys.

From your valuable inputs, I now have a clue that the adapter looks like a T2 adapter with the inner (presumably threaded) ring removed.

I will buy a T2 adapter (with PK mount) to try it out.

One more question:

Are T-mount and T2-mount adapters similar?
Do both T and T2 adapters have inner ring that is removable?

I want to be sure about what to buy before I search eBay.
Look forward to hearing from you all.
Thanks again.

luisalegria · Expire: 2018-01-18

I believe that t and t-2 adapters always had removable inner rings, as I have what must be one of the original t-adapters, that came on a Duo-Tamron 135 vintage 1957.

I have a dozen of these things at least, and all have removable rings. The term seems to be completely interchangable these days. You should be safe buying anything called a t or t2 adapter.

What you should do, or try, though, is to put the outer ring back and screw the set-screws down tight. Then unscrew the whole thing off, inner and outer rings together. Thats how t-adapters work. " target="_blank">Click here to see on Ebay

dancheng · Joined: 28 May 2008 Posts: 7

I spent a princely sum of $8.40 inclusive of shipping to buy a T2-PK adapter at eBay. Removed the inner threaded ring, and it fitted the mirror lens perfectly.

I now have a 500mm f8 lens with PK mount for less than $84 including shipping. Need to find a bright day to try it out on my Pentax k10D.

Thanks for all comments and suggestions.

luisalegria · Expire: 2018-01-18

Good luck with your mirror lens !