Image of the day

Captured by
RICHARD COFER

VdB 141 Ghost Nebula

About Astromart

My Account

New to Astromart?

Register an account...

Need Help?

Posts Made By: Walter Hamler

May 5, 2002 01:37 AM Forum: Equipment Talk

comments on the orion 120ST refractor

Posted By Walter Hamler
What eyepieces are you using? Are you using the diagonal? I had a chance to view with the SkyWatcher version of that scope at Chiefland last year, and under great skies with a 35mm Panoptic, the Veil nebula, NA and Pelican Nebula were great, without filters. It's not a planetary or lunar scope, so don't even expect it to look decent at higher mags, except for faint fuzzies. We did look at M-81/82 also and remember it to be a very nice contrasty view.

Walt

May 12, 2002 09:02 PM Forum: Telescope Making

Mirror coatings

Posted By Walter Hamler
In earlier posts I have recommende Astrocoat in San Carlos, CA http://home.covad.net/~alcoat/

Prices are very reasonable, but the best think I like is quality and service. He is FAST!! and very honest. Has done 3 or 4 mirrors for me and presently has a 10" for coating.
I have also used Spectrum, and while I have no complaints with his quality, the cost was double and the service was lacking. The only complaint I have with Clausing is he is always busy so the wait will be longer.

May 18, 2002 11:28 AM Forum: Telescope Making

8" f/5 Ideas

Posted By Walter Hamler
If you get a copy of Berry and Kreige's book, The Dobsonian Telescope, the appendix has plans for a very nice 8" f/6 dob. I have made several from this plan and it is an excellent design and easy to make. I think you will find that with an 8" f/5 you can rotate the tube in the tube cradle to such an angle that the eyepiece is comfortable from a setting position from about 30* to the zenith. I would mention that if you use sonotube (the thicker construction grade) just several good coats of a quality latex is really all you need to make it sturdy, especially for such a short tube, so the Kydex wrap is overkill.
Walt

May 29, 2002 11:04 PM Forum: Deep Sky Observing

Colorful stars in globulars?

Posted By Walter Hamler
Until recently it was thought that the stars that make up globulars are all Pop II stars, ie, very old, and all of similiar color/temp. This is still "mostly" true, but recent Hubbel stuff has shown new star formation fields in globulars. It is felt that this is due to some type of interaction of the globular with an outside influence, such as supernovae or merging with other galaxy or globular. All this is to show that there "normally" won't be much variation in color within a globular, and therefore your eye will tell your brain it is any color it wants it to be. There are always exceptions however.

Walt

June 9, 2002 07:22 PM Forum: Equipment Talk

EQ Platforms

Posted By Walter Hamler
If you are the least bit handy with tools/woodworking, you can build one yourself for less than 100.00. I have built two in the past couple years and have had up to 15" dobs on them with no problem. Go to http://www.stellafane.com Look under "Scope Gallery", and the pic of the tracking platform. Basic info is there.

Walt

June 12, 2002 11:37 AM Forum: Film Astrophotography - Imaging and Processing

Polar Alignment

Posted By Walter Hamler
Go to http://www.astroleague.org/al/astrnote/astnot01.html

There methods worked very well for me. I use a GEM but the principle is the same with the fork mount or whatever.

Walt

June 20, 2002 11:44 AM Forum: Telescope Making

baffle materials

Posted By Walter Hamler
Although I have heard of baffles in newts, I have never actually seen them used. Most folks paint a very dead flat black , mix crushed nuts, or other "sawdust" materials with paint, or use the "flocking" type contact paper to line the inside of the tube. I just had my first experience with the flocking material in my 10" f/6. It is really amazing just how dead it makes the inside, just like a "black hole!" Also, I have found a very inexpensive source for the material. It is available from http://www.mcmaster.com/
listed under Velvet in the Fabrics section. The choice without the adhesive backing is especially nice as it allows one to install using spray adhesive which is easier than the adhesive backed material.

Walt

June 22, 2002 11:38 PM Forum: Telescope Making

Tube material

Posted By Walter Hamler
I once made a 4.25" f/13 newt to use as a guide scope. I used a .8" secondary on a homemade spider. PVC tubing makes a good secondary holder, and a curved spider would also be a good choice. A recent S&T article has some good pointers on the curved spider. Naturally the mirror can be left spherical and it should give pretty crisp images. I believe Apogee used to sell 5.5" OD rolled steel tubes, but don't know if they made them in 45" lengths. You might find a mailing tube that would work after several coats of polyurethane. Good luck!

Walt

June 23, 2002 03:17 PM Forum: Telescope Making

Applying Felt /Flocking paper to Tubes..........

Posted By Walter Hamler
Great idea. I will be putting some of the non adhesive backed material in our club scope in a few days. I'll give it a try and let you know how it works.

Walt

June 24, 2002 11:17 AM Forum: Equipment Talk

Cleaning EP's and ever popular lens cleaning pen

Posted By Walter Hamler
The lens pen is a very good way to clean eyepieces and camera lenses. I have used them for years with no negative results. You must replace them after a period as the cleaning surface can become contaminated with embedded material that could cause problems. Always examine the cleaning surface before use. Once I started to use one and the cleaning surface had come off the backing which is a rubber type material.

Walt

Funding Member

Sponsors


View all sponsors

Search