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Posts Made By: Alex McConahay

May 19, 2002 06:55 AM Forum: Film Astrophotography - Imaging and Processing

Lumicon Easy Guider

Posted By Alex McConahay

Hi all,

I'm thinking of buying a used "Lumicon Easy Guider" for use on my Celestron 9.25. The device has a four inch long 1.25 i.d. tube off the pick-off mirror, and a two inch main tube with some optics in it. On the camera end of the main tube, there are three set screws, but no other adapter. ON the telescope end of the main tube, there are three set screws. That end of the tube seems to be just a bit larger than two inches for the first quarter inch. (all measurements by eyeball)

Just what do I have here? Where can one go for better information. I cannot find anything at Lumicon website, and a Google search turned up stuff for the Giant Easy Guider, but not this one.

It seems I am missing some end pieces (Telescope to guider/ Guider to T-adapter). I am familiar with Off axis guiding, having done it with a 1.25 version.

All advice welcome.

Alex

June 8, 2002 02:42 PM Forum: Film Astrophotography - Imaging and Processing

TV 85 Vignetting

Posted By Alex McConahay

Hi all,

I'm thinking of getting a TV 85 to replace my Ranger. The only real drawback to the Ranger is extreme vignetting in astrophotos.

Does the TV85 vignette with a 35 mm camera? (Actually, I suppose all optical systems vignette to some extent--but is it a real consideration in a TV 88?)

Alex

July 8, 2002 08:28 PM Forum: Equipment Talk

Re: Losmandy G-11/Celestron ?? Urgent!!

Posted By Alex McConahay

Mike,

I have a Celestron G-11, manufactured by Losmandy. It says Celestron by Losmandy on it. THey are the same product. When Celestron took over, things changed, and the mount became more angular and not quite as beefy. Still a very good mount, though.

Incidentally, I have the Losmandy digital setting circles on it. The only problem I had was that the counterweight bar had to be trimmed down a bit in a lathe before everything would happily fit together again.

Alex

July 15, 2002 07:42 PM Forum: Equipment Talk

Re: G.925 to a CI700 What's needed to mount?

Posted By Alex McConahay

Assuming the C1700 is in fact the same system as the G-11 as far as this goes, you will need a dovetail plate, and two radius blocks.

I called a place called Anacortes. They are pretty good people, and set me up for about $100.

Give them a try. I don't have their link handy, but you should be able to find them someplace.

Alex

July 21, 2002 09:16 PM Forum: Equipment Talk

Re: C-11 and G-11 Problems$$$ Just Bought

Posted By Alex McConahay

Mike,
Start with the clutch knob--on a G-11 it never snugs all the way up. YOu will be able to move the tube smoothly even when it is as tight as it can be--and it does not need to be too tight.

As for the wiggle back and forth. It sounds excessive, but otherwise it is just a worm gerar out of adjustment--there's a good website mentioned by another poster.

Relax--it is a great mount, and it will work for you.
Alex

August 21, 2002 06:39 PM Forum: Equipment Talk

ParaCorr

Posted By Alex McConahay

Hi All,

I'm just about finished with my 12.5 F 4.82 truss-tube Newtonian. I am contemplating needing a ParaCorr. I have a 9 Nagler, 15 Pan, 22 Pan, and may be getting a longer focal length wide-field eyepiece.

1. How much does a ParaCorr weigh?
2. What effect does it have on focus? How much does the focus move in or out? (will I need more in-focus, more out focus travel, or does it focus at about the same place as the eyepiece alone)
3. Can I use a ParaCorr for astrophotography as well as visual?
4. Any other thoughts?

Alex

September 21, 2002 01:42 PM Forum: Telescope Making

Slipping Crayford

Posted By Alex McConahay

Hi All,

I have a 2 inch crayford focuser. Says Apogee UHDC on the side. It slips severely, and cannot hold focus. It seems as if everything is in place. A metal shaft rubs directly against a flattened area on the focuser tube--

The focuser has four adjustment screws to tighten up the motion. However, they cannot be tightened down sufficiently to make good friction because the adjustment screws cut into the barrel.

SO--
Is there supposed to be something on the metal shaft to help create friction?

Should I just shorten the adjusting screws so they can be tightened without cutting into the barrel?

What's the best way to take up the slack?

Alex

November 11, 2002 12:34 PM Forum: Film Astrophotography - Imaging and Processing

OM-1 Replacement Battery

Posted By Alex McConahay

Hi all,

I'm going on a faraway trip soon. I plan to use my Canon Elan during the day, and my OM-1 for piggybacking and prime focus at night. I figured, why not get a battery for the OM-1 so I can use the meter during the day if it becomes necessary or I just want another camera.

Just what battery goes in there? I understand you cannot buy the original battery. And I do not know what it was, anyway.

I have tried a 625 and a 357. Both give me the same readings. And they give me the same readings on both my OM-1 bodies. But the readings do not match the Canon--whose meter I know is correct.

If I cannot find a replacement batery, can I just adjust the film speed dial on the OM-1 to make the needle match the Canon reading, and thereby fool the meter, even if it does not have the correct battery?

Alex

November 17, 2002 07:33 AM Forum: Film Astrophotography - Imaging and Processing

Eclipse video

Posted By Alex McConahay

Who has experience using a video camera to record an eclipse?

How is it done--Manual focus? Adjusting the exposure? What all does one need to do to capture the event?

Alex

January 20, 2003 09:15 AM Forum: Telescope Making

Turned Down Edge--Grind it Off?

Posted By Alex McConahay

I have an old beveled pyrex blank, 8 inches, F 4.35. Good polish, nice sphere. The last couple of mm are turned down. I had a good edge until I started figuring. 1After losing the edge, I have spent about two hours tool on top, pressure on outside edge of six inch tool, small W stroke on the edge of mirror. I cannot get more than the dimmest of diffraction rings on far side, and the Ronchi's take the slightest turn at the very end.

Should I go figure, and then when done turn the mirror over on a piece of glass and fine grind the edge, or fine grind the edge now, and then figure, or put in more time trying to get the edge back with the stroke I have been using? Is there a better stroke to try?

Alex