CTSP 2004 - Hosted by the Austin Astronomical Society

Filters: Nebula, Polarizing, Broadband, Narrowband, Solar

The Canyon of the Eagles was the site of the Central Texas Star Party 2004. This year was the one of the most attended parties held to-date. For information about other Austin Astronomical Society events, check the website at www.austinastro.org.

Remember, I'm the guy who always shows up with telescope and mount combinations that do not exceed $2500, but this does not prevent me from thoroughly enjoying the absolutely beautiful HUGE telescopes that show up. In my opinion the winner of the coolest outfit at the star party was Todd Brower who, on Friday night, set up his home-made 12" Newtonian reflector mounted on the humongous Losmandy Titan mount.

I'm talking about over $5,000 worth of the most beautiful, "portable" equatorial mount I've ever seen in my star-gazing life. If you ever get a chance to see one up close, take it. The polar-alignment scope is a truly amazing piece of equipment that should be retrofitted to use on any equatorial mount made. I'm already contemplating purchasing one of those polar alignment scopes in the hope of MAKING it work on a SkyView Pro mount. I'd LOVE to obtain polar alignment without having to perform a drift alignment! I know it's not likely, but a guy can dream huh?

What made it remarkable were the alignment marks in the glass. You had a marked area to frame Polaris of course, but there were a couple of other marked areas where you place two other dim stars. Once you have all three stars in their place you are good to go. Todd didn't have to do one bit of drift alignment after that. Impressive.

Miguel Betancourt of Spacewalk Telescopes fame was set up quite close to me on Saturday night. I had the opportunity to take a close look at his truss design. These are without a doubt the best fit and finished truss-Dobs I've seen. There is not a square corner on them! He had a 20" model and it's baby brother the 10" nearby. Both were beautiful examples of Miguel's standards of excellence. I was able come by later and view a number of objects through both the 10" and the 20". The views were incredible! Miguel uses several sources for his mirrors. One of his sources is a guy by the name of John Hall who produces mirrors under the name Pegasus Optics. John happened to be set up not 10 feet from us. There were several large Dobsonians out on the field that night with John's mirrors in them.

I know I'll probably go straight to affordable scope hell for even mentioning all these expensive scopes, but they were so dern purty!!

The scope you see on the left is what I call a Lottery Scope. In other words, I'll never own one unless I win the lottery, and even then I'd have to think it over for a couple of years. The AstroPhysics equitorial mount on a Particle Wave tripod with a Takahashi 12" Mewlon topping it all off, was decidedly the most expensive rig on the field.

All I can say is.....it looked really nice.

"Really, really nice.

yup.

Nice."

 

The Nebula Filter Test

A few weeks back, Richard, from the Austin Astronomy and Science Shop, and I performed a side-by-side comparison was between the BandmateTM NebuStarTM and the Orion UltraBlock TM filter. The Orion UltraBlock was picked hands down.

Thanks to Jim Henson, owner of ScopeStuff.com I was able to do yet another nebula filter test at the CTSP. This time it was between the Orion UltraBlock and the Andover 3-channel Nebula filter. This was a tough test.

Two TeleVue Panoptic 24's were my test eyepieces. I placed each filter in a Pan 24 and walked around the field asking people to participate in the shoot-off. I presented them only as "exhibit A" and "exhibit B", and asked each person to try both, switch as many times as is necessary, then choose the one they preferred.

Nine observers took part in the comparison using the same eyepieces but on about five different scopes ranging from 10 inches of aperture to 20 inches. Some were veterans with decades of viewing under their belt and some were beginners. The results were interesting. Those who were familiar with nebulae filters tended to choose the Andover filter and those who had less experience with filters in general tended to choose the Orion.

Although both filters revealed a view with good contrast and nebulous cloud detail, they were so close that unless I pressed for a decision from the participant, they would have settled for "It's a toss-up". Those familiar with nebulae filters thought that the Andover filter actually showed more stars, and subsequently brighter stars, than the Orion UltraBlock.

Henson explains it this way: "The Three Channel Nebula Filter works very well for both emission and planetary nebulae. Unlike other nebula filters, this filter blocks sky glow and passes emissions from the nebula, but also passes a selected band of blue light which enhances the star clusters found in the nebula. The filter also passes the Hydrogen Alpha line which is important for photographing emission nebulae. These three pass bands are unique to the Andover Three Channel Nebula Filter."

Four chose the Andover. Four chose the Orion. One declared a toss-up. A tie. hmmmmmmmm. The deciding factor then must come down to price and preferrence.

The Andover filter costs $125.

The Orion UltraBlock costs $80.