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Posts Made By: Judson Mitchell

June 27, 2006 08:29 PM Forum: Eyepieces

StarSplitter 5.9mm First Light

Posted By Judson Mitchell

This is only a novice first light on a SP 5.9mm EP. Telescope was a 12" F/5 HOC Dob. There was some thin high clouds and significant light domes. At the edge of red/orange on the light pollution scale. Seeing was maximum Pickering 5 and commonly less, however a reasonably steady image of Jupiter was possible.

On axis focus of the SP was sharp and maintained until about 80% out where sharpness began to deteriorate. Not objectionably but obvious. I was able to refocus "down" to regain sharpness at about 90-95% out to the edge. This direction of refocussing may say someting to those more knowledgeable about EPs. I would be interested in their comments. I did not observe any chromatic aberrations or distortions at the edge of the FOV. It was difficult to make any comparisons to other EPs. I used a barlowed 11mm Tele Vue Plossl (220X); the StarSplitter was about 255X; and an 8mm Hyperion barlowed to about 320X. As power increased a corresponding decrease in sharpness and contrast was observed which should be expected. No real other comparisons or conclusions therefore could be made by me. On a 3-4th mag star slight bloating began at about 90% out and gradually increased to the edge.

June 30, 2006 12:35 PM Forum: Beginning Astronomy?

Re: Not so sure aperture is the way to go...

Posted By Judson Mitchell

"Aperture will get you through times of no money better than money will get you through times of no aperture."

July 7, 2006 10:14 AM Forum: Sports

Tour de France

Posted By Judson Mitchell

Wouldn't want you guys to slight the Tour de France. Not your zoom-zoom high impact, parts flying kind of racing, but one with drama for those who take the time to understand it. Plus, it is one of the most wide-open Tours in years with several legitimate contenders. Tomorrow will be a defining day with the 52K individual time trial.

July 12, 2006 10:15 AM Forum: Eyepieces

Leitz 30 mm 88° WwPlanokular WOW!

Posted By Judson Mitchell

OK, at $1500 and 1.8#, has anyone ever even been near one of these? And if they are that valuable, what is it that makes them so good. Touted as 30mm and 88 degrees. Is it the name? Can anyone attest to the performance of this EP? Reminds me of the Smuckers commercials. " With a name like------------

July 12, 2006 10:30 AM Forum: Equipment Talk

Odd Star Test When Cooling Mirror

Posted By Judson Mitchell

When my mirror is still cooling and I focus out on a star test there is a triangular pattern in the test like a tri-spoke bicycle wheel overlain on the pattern. This pattern is not present when the focus is in. My intiution suggests it has something to to with the mirror clips, but the absence on the in-focus test is puzzling. When the mirror is stabilized the pattern is gone. Also, I have ordered Suiter's book but haven't received it yet so I cannot consult that tome. Any suggestions: Don't worry/loosen your clips/wait until it is cool to do a star test?

July 13, 2006 12:38 PM Forum: Reflectors

Do Shine a Bright Light on your Mirror!

Posted By Judson Mitchell

OK! I have read all the dos and don'ts so I knew I could take it. After all I use a white light at times to collimate with my Jim Fly. Well, yesterday I decided to risk checking out all the pinholes in my mirror coating; as I said, I can take it. Wait a minute! Where did all those scratches come from??? My gosh there are hundreds of them. How come I didn't notice them before, particularly when I cleaned my mirror a few months ago. You gotta be kidding me? Panic Panic! Then I saw the small spider in a thin web near the trunion bolts. Serves me right for not keeping the shower cap on the end of the scope, after all it interfers with my battery pack and wiring to the fan.

So maybe it is not such bad advice to shine a light on your mirror once in a while, if you can take it. Took my wife's duster, estimated the distance to the mirror and then swept the cobwebs away. Scratches gone.


July 17, 2006 09:20 AM Forum: Reflectors

Re: and another

Posted By Judson Mitchell

Is it possible that the person you got it from had it set up for bino viewing and that the poles were shorter. Sounds like the pole lengths are wrong for normal viewing.

July 17, 2006 12:50 PM Forum: Reflectors

Re: please help with new starbuckets dob

Posted By Judson Mitchell

Nils
When I loosen the knobs on my scope, the mirror moves forward not back. Does your mirror move in the same manner. Is it possible your were allowing the mirror to move forward with your adjustment? However, it still doesn't seem like enough adjustment to cause the problem you are describing.

July 27, 2006 05:19 AM Forum: Sports

Landis on Leno

Posted By Judson Mitchell

I believe Jay said that Landis would be on the Tonight Show Friday night. Landis is not a very outspoken person, so it will likely be fairly level, but he may have an update on his Hip.

July 27, 2006 09:23 AM Forum: Beginning Astronomy?

Re: Barlow on a fast scope

Posted By Judson Mitchell

On my F/5 12" HOC dob I had to move the mirror forward to reach focus when using my 1.5 barlow, then my 40mm TV Plossl needed an extender to obtain focus. Can't win them all. Perhaps there is enough movement available in the mirror to bring the barlow into focus, but there is also the risk that it may compromise the focus for un-barlowed EPs.

Also, I had to strengthen the springs on the mirror mount when I did this or the mirror shifted. I used #52 springs from Ace Hardware. Cut them in half to avoid the springs binding in compression. All in fun of course.