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Old Dec 14, 2007, 11:15 PM   #21
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Roy, yes I do look at the skies some nights though really only a rank beginner in the field.

It think it will go well for astrophotography, time will tell!
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Old Dec 17, 2007, 10:14 PM   #22
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I have got it back from being cleaned and a few loose bits fixed plus the sticky focus has been cleaned an relubed.

The bad news is that the focus is now very slack, I turn it past focus in one direction then need to turn it way back to get to where I was. This makes it very difficult to focus.:sad:

Maybe I should look for a Pentax 1.4autofocus adapter, trouble is it would cost way more than this lens.:roll:




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Old Dec 17, 2007, 10:59 PM   #23
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John..I'm sure you know this but the Heavy grease is used as a dampner for the focus mechanism. If they cleaned it all out and didn't replace it with a heavy enough grease then it would focus in the way you are talking about...It may have to be returned and a heavy weight grease used in it! It may be that the way this lens focuses it has more mechanical leverage than a normal lens and would require a different viscosity grease than the lens repair shop is used to using these days.



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Old Dec 18, 2007, 12:10 AM   #24
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You could be right Dawg though the serviceman I use is rather "old-school" and I would expect him to use the appropriate grease.
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Old Dec 18, 2007, 1:18 AM   #25
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John Hill wrote:
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You could be right Dawg though the serviceman I use is rather "old-school" and I would expect him to use the appropriate grease.
But the apropriate grease for a small lens may not be viscous enough for that monster you have there. Just a thought!! Must be nice to have a lens repair shop handy...Have to send mine 350 miles to get it worked on.

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Old Dec 18, 2007, 2:43 PM   #26
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I fear that what has happened over the years is that the grease has got thicker requiring more force on the focus ring which has strained the grooves in the helix which is only made of very soft alloy.

My repairman is within (30 minutes) walking distance from the office so I am indeed fortunate in that respect.


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Old Dec 18, 2007, 4:56 PM   #27
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That is one big ugly mother f----r :-)



Hope you get that grease sorted
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Old Feb 4, 2008, 1:50 AM   #28
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Just finished making a HUGE improvement to this lens, here is a picture of the focus control as orginal:





Here it is again but this time with a full diameter focus control my friend turned from 10mm aluminium for me, all nicely anodized and profiled to match the shape of the lens unit. Note the knurled edge that is the full diameter of the lens and promises to be extremely easy and accurate to use compared to the original scheme of being barely able to reach the focus ring with the finger tips.


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Old Feb 4, 2008, 5:40 AM   #29
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Hi John,

Really nice! I would probably have just cut threads onto the end of an aluminum rod and replaced the thumbscrew -- but that wouldn't work as nicely as your setup will. The added diameter will probably make fine focusing a lot easier even without the previous clearance issues.

Is that thumbscrew a focus lock, or maybe a tension adjustment?

I'm looking forward to some pics from the revitalized beast. . . but you probably have to train a while to get in shape before tackling that --:-)

Scott
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Old Feb 4, 2008, 3:32 PM   #30
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Hi Scott

The thumbscrews are part of the T mount adapter and you slacken these off to rotate the mount for portrait/landscape modes.

Yes, I am looking forward to taking this out in the field but still some work to do plus I will be away from home for 5 weeks or so and this little fellow will be staying behind!:sad:
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