[stevebrot]

That does look like a nikon mount. I'd remove it and see if there are m-42 threads under it. I have a heavy pentax k-mount from my discarded tokina 500mm mirror lens. If you think you can use it let me know and i'll ship it to you

My thoughts too...it looks like someone grafted it on.

Steve

[monochrome]

Takumar bayonet? come on now... its not that bad.

I didn't tell you what I paid for it

[ivoire]

Here're the pics of the detachable portion at the end of my 1000mm f/8:

In Pic #2, the piece with the red dot on it should be removable. I'd take it off and see if there is a m42 screw mount thread.

[deadwolfbones]

Yeah, it is removable. There's a screwmount, but it's definitely not M42. It's far wider than the F-mount above it.

I'll post some pics with it detached tomorrow.

[gofour3]

Jeez this is quite the mystery. We may need Sherlock Holmes to figure this out.

[Ben_Edict]

Yeah, it is removable. There's a screwmount, but it's definitely not M42. It's far wider than the F-mount above it.

I'll post some pics with it detached tomorrow.

To me that Nikon mount "piece" looks like a simple T2-Adapter. That would suggest, that somebody also added some kind of M42-to-T2-adapter beneath it (assuming, that the rear ends with the M42 screw mount. It certainly looks on your images, as whether there is a second adapter below the Nikon adapter (you see the screws in these adapters, which allow to adjust the mount rotation, to have the camera always aligned with the lens's markings).

So, if my assumption is correct, you just would need a standard Pentax K-M42 adapter, remove the two adapters in place and then can use the lens.

Ben

[glasbak]

To me that Nikon mount "piece" looks like a simple T2-Adapter. That would suggest, that somebody also added some kind of M42-to-T2-adapter beneath it

Yes, it looks like T2, no I do not suspect M42 anywhere.
A T2 adapter has 2 parts, the camera specific mount part, with inside a dovetail shaped ring with the 42x0.75 thread held in place with 3 small screws.

Now you have to order a K mount T2 adapter, with the same dovetail ring diameter as the current one, and then you are in 'business'.

Indeed the SMC PENTAX 500mm and 1000mm back parts are identical.
I read in this thread that there would be a 6x7 adapter for the 1000mm, but I doubt it, I suspect this would give serious vignetting.

George

[deadwolfbones]

Some more pics with the piece detached:







Can't get a really precise measurement, but the outer diameter of the main tube piece (with the F-mount adapter removed) is about 55mm or 2 & 3/16". The diameter of the screwmount on the F-mount adapter is about 51mm or 2".

If you guys need any more shots to help you figure it out, let me know.

[Ben_Edict]

Yes, it looks like T2, no I do not suspect M42 anywhere.
A T2 adapter has 2 parts, the camera specific mount part, with inside a dovetail shaped ring with the 42x0.75 thread held in place with 3 small screws.

Now you have to order a K mount T2 adapter, with the same dovetail ring diameter as the current one, and then you are in 'business'.

Indeed the SMC PENTAX 500mm and 1000mm back parts are identical.
I read in this thread that there would be a 6x7 adapter for the 1000mm, but I doubt it, I suspect this would give serious vignetting.

George

1. there must be either a M42 thread or a k-bayonette somewhere "below", - or somebody has manufactured his own adapter. This lens was only available in M42 /K or 67 mount, never in T2.

2. I definitely know(!) that the 67-adapter was availabe for the 500/4.5 and a small number of these lenses were actually sold for 67 directly. I cannot see, why the 1000mm would introduce vignetting, where the 500mm doesn't.

Ben

[Blue]

D.W.B,

Will the smaller piece come apart further?

[deadwolfbones]

D.W.B,

Will the smaller piece come apart further?

No, it's solid.

F-mount on one end, 51mm screw on the other.

edit: actually, wait... there are screw threads on the interior. Nothing on here is narrow enough to be M42, though.

[Blue]

No, it's solid.

F-mount on one end, 51mm screw on the other.

edit: actually, wait... there are screw threads on the interior. Nothing on here is narrow enough to be M42, though.

It that case, perhaps you should take the offer on the k-mount from the Tokina lens. machine off the F mount, drill and tap for the K, put sealer in between the surfaces (Blue Locktite) and call it done. I wouldn't use the locktite on the screws though.

The second option would to be to get yourself an 500mm (if the piece would work on both which needs verification) and use it on both lenses and save this one for Nikon.

Edit: Perhaps turn around an resell the 500mm as a Nikon mount 500.

Edit: Edit: That's if it isn't T2 compatible.

[deadwolfbones]

Waaaaait... just had another look, and I think it may actually be a M42 screw that the Nikon mount is screwed into (based on nothing more scientific than holding the base of my J-9 up to the Nikon mount and noting that it very nearly but not quite fits inside).

[dadipentak]

No, wait--it's brass?!

[glasbak]

1. there must be either a M42 thread or a k-bayonette somewhere "below", - or somebody has manufactured his own adapter. This lens was only available in M42 /K or 67 mount, never in T2.

2. I definitely know(!) that the 67-adapter was availabe for the 500/4.5 and a small number of these lenses were actually sold for 67 directly. I cannot see, why the 1000mm would introduce vignetting, where the 500mm doesn't.

Ben

1 : it was clear from the first pictures that this adaptation to F mount was a destructive one. The M42 part is gone.

2: both the 1000mm and 500mm have baffles designed for a smaller image circle, even if the optics are able to fill a 6x7 image, the baffles will prevent that.

@deadwolfbones : read my advice about removing the F mount T2 piece, you are 3 scews and a K mount T2 adapter away from a working solution.