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Posts Made By: Pat Plunkett

June 9, 2002 05:54 PM Forum: Equipment Talk

Green-Light Laser

Posted By Pat Plunkett

Hi All:

Does anyone know where I can get one of these for a reasonable price (i.e. < $100)? I don't trust e-bay for things like this...

Pat

P.S. If you've got one to sell, I'm interested...

November 4, 2002 06:44 PM Forum: Equipment Talk

Re: off-axis parabolic reflectors

Posted By Pat Plunkett

I looked through a 10" f/10 (yes, f/10) Herschel (sp?) at the Laurel Highlands Star Cruise both this summer and the summer before. WAY cool! Superb views and fairly convenient to use (it was mounted more-or-less as a Dob). Only weird thing is that you have to be very careful where you position your head as it may block the light path. Note that the Herschel has no secondary mirror.

Pat

March 11, 2003 08:43 PM Forum: CCD Imaging and Processing/Solar System

First Post - Straight wall

Posted By Pat Plunkett

Here's my first post here... The subject is obvious. Took it with a hand-held Sony DSC-S50 CyberShot through a 32mm TV Plossl, using on-camera zoom. Oh yeah, the scope is a Discovery PDHQ 10". This was from my suburban back yard with average seeing...

Pat

October 11, 2003 05:57 PM Forum: Equipment Talk

Refractor Astigmatism

Posted By Pat Plunkett

I just bought a 90mm refractor from an astromarter and have found that it has rather bad astigmatism (it's an Orion f/11). I know it's "caveat emptor" here on the 'Mart and am not complaining - i got a decent mount as part of the deal. My question is this... Is there any way to correct it (I doubt it)? I have verified that the problem lies in the objective and have taken it out and replaced it to see if anything is "pinched" or misaligned (it wasn't). I did see a "K" on the side of the second lens (of the doublet) and two sideways "D"s on the "front" lens, 180 degrees apart. The previous owner had obviously removed the lens set at least once.

Thanks for any help - I suspect that I'm just stuck with an astigmatic 'scope...

Pat

January 31, 2004 06:00 PM Forum: Equipment Talk

Source for refractor lenses?

Posted By Pat Plunkett

Hi:

I want to build something like the "Sunspotter" solar observer and am trying to find a LONG focal length lens (probably about f/20) in a size around 60mm. Any ideas? I tried Edmund, but got lost on their site (and the biggest lenses I could find were 50mm).

Pat

February 9, 2004 07:20 PM Forum: CCD Imaging and Processing/Solar System

Digital Rebel question

Posted By Pat Plunkett

I finally had a chance to try out the DR with my 12.5" dob last night and was disappointed to find that I do not have enough in-focus in prime OR with projection. Are there any cures for this or do I just give up? I can get focus on my ETX-90 (using eyepiece projection), but the edges of my photos are blurry (not vignetted, blurry). Are all these problems due to the distance to the film plane?

Pat

May 4, 2004 07:47 AM Forum: Equipment Talk

LONG focus lens???

Posted By Pat Plunkett

Does anyone know a source for refractor lenses with LONG focal lengths? My club uses a ~5" lens and a diagonal mirror to project a solar image which is in focus about 50 feet away. I guess this would be about an f/120...

Pat

June 8, 2004 06:44 PM Forum: CCD Imaging and Processing/Solar System

Venus from Wellsburg, WV

Posted By Pat Plunkett

Enjoy - equipment: Digital Rebel, ETX-90, Baader solar film - processed with PhotoShop...

Pat

August 6, 2004 08:16 AM Forum: Equipment Talk

CG-5 Tracking Issue

Posted By Pat Plunkett

Hoping for a little advice... Last night I tried some unguided photography with my new (to me) CG-5 mount and my TV Genesis. I think I have an RA motor or mount problem as I end up with little U-shaped stars after a 2-minute exposure. I think I had a good alignment as the star streaks aren't linear. My question is this: is there something I can tighten or adjust to fix the problem? I did note that the RA slow-mo axle (not the main axis, just the little one) seems to be a little bent - that is going to be my first point of attempted repair. Anyone have a similar problem?

Pat

December 3, 2004 07:52 AM Forum: Refractors

Re: Jaegers Optics

Posted By Pat Plunkett

Lots of poor spelling on the home page? I don't trust sites like this, but that's only one person's opinion...

Pat