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Old Nov 25, 2008, 10:31 PM   #11
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Hi John,

What I'm curious about is how the F 1.7x AFA works with this beast. An AF 850mm f6.8 would be something. . . even if you do need a truck to haul it around.:-)

Scott
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Old Nov 25, 2008, 11:16 PM   #12
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Hi Tim

There is no problem with clearance and my *ist DS though it was a challenge to reach the focus ring on the lens, I solved that by making a full diameter focus 'wheel'.
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Old Nov 25, 2008, 11:20 PM   #13
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Hi Tim

There is no problem with clearance and my *ist DS though it was a challenge to reach the focus ring on the lens, I solved that by making a full diameter focus 'wheel'.



Hi Scott

I have not had it out with the AF adapter yet though I did fit it and test it would work OK. The T mount adapter is anodized aluminum which is not a good conductor for the contact pins on the front of the adapter. I cured that by a little process I have developed where I put a mounting ring (taken from a defunct teleconverter) on the back of the lens. The mounting ring has holes where contact pins used to be and it was just a moments work to use a sharp point to scrape away the anodizing in line with a couple of the holes.




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Old Nov 30, 2008, 1:56 PM   #14
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It has arrived!

Although an obvious close relative of the one I already have this new arrival is quite different. It has a mount on the back, the tapered type like a T adapter would mount to but it is quite big compared to the bits I have already, the mount is about 2 1/4" or 58mm in diameter. There is a reducer/adapter/teleconverter on there which takes it down to 42mm (same thread as camera) so with an adapter ring the camera mounts OK but I cant get focus.:sad:

The teleconverter thing might not be intended for this lens as it is marked 1:8 f=1000mm but this lens is only 500mm, hmmm, might or might not be original do you think?

Someone has had the lenses out of the TC which might be the cause of no focus but really I dont need this, I would rather get the Pentax AF adapter to mate up to the 58mm diameter taper. Is now the time to lodge an application with the domestic finances management for authority to buy a little lathe?:roll:

Otherwise the lens looks in great shape though rather dusty some of which might be inside, mirrors primary and secondary look nice and clean.



But hey, how cool is this? It has its own neat leather** strap on jacket which incorporates the carry handle?:G

**(leather from a vinyl cow)






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Old Dec 1, 2008, 2:20 AM   #15
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I got the new piece home and put it alongside the other one. Hmmm, the bits I thought were bigger are actually the same size on each lens!

When I was messing around with it I found the rear turret tube (or whatever one might like to call it) is loose in the body and can slide out. I am not sure if this is a fault or some macro facility! Nothing to indicate the later.

I contacted the previous owner who said it came from his uncle who was a telescope technician at an observatory so I guess I should not be suprised to come across the odd 'modification'!

The teleconverter thing is apparently 8x ! No wonder I could not focus it, it is effectively 4000mm f32! I will be putting that aside until I get an adapter made for my equatorial telescope mount then we might see some space images! Meanwhile I think I will need to have an adapter made to mount my camera, it should be a simple metal turning job and a K mount adapter screwed on the end. Unfortunately I dont have the skills or tools for that job but at least I have pieces on the other lens to measure.

Considering the marking on the TC I guess it was originally intended to be fitted to something like a 120mm F2(?).



I am alsoconsidering treating this new one to a professional clean and align, I know a man who does a good job at a reasonable price.

So what can I do with two of these? A stereo camera? Monster binoculars? Could I join the light paths and make a 500mm f2?:G











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Old Dec 1, 2008, 9:15 AM   #16
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John Hill wrote:
Quote:
I got the new piece home and put it alongside the other one. Hmmm, the bits I thought were bigger are actually the same size on each lens!

When I was messing around with it I found the rear turret tube (or whatever one might like to call it) is loose in the body and can slide out. I am not sure if this is a fault or some macro facility! Nothing to indicate the later.

I contacted the previous owner who said it came from his uncle who was a telescope technician at an observatory so I guess I should not be suprised to come across the odd 'modification'!

The teleconverter thing is apparently 8x ! No wonder I could not focus it, it is effectively 4000mm f32! I will be putting that aside until I get an adapter made for my equatorial telescope mount then we might see some space images! Meanwhile I think I will need to have an adapter made to mount my camera, it should be a simple metal turning job and a K mount adapter screwed on the end. Unfortunately I dont have the skills or tools for that job but at least I have pieces on the other lens to measure.

Considering the marking on the TC I guess it was originally intended to be fitted to something like a 120mm F2(?).



I am alsoconsidering treating this new one to a professional clean and align, I know a man who does a good job at a reasonable price.

So what can I do with two of these? A stereo camera? Monster binoculars? Could I join the light paths and make a 500mm f2?:G










8X!!!!!!!!!!!!!! Geez!!!

Dawg
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Old Dec 1, 2008, 11:55 AM   #17
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Thats about what I thought too when I realised what it was, I cant think of any practical use for 8Xexcept in astrophotography, which was the field this guy was into.




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