RTMC Wrapup!

The Riverside Telescope Makers Conference (RTMC) is an annual gathering of amateur telescope makers, as well as astronomy vendors and astronomy nuts of all sort. Always held over Memorial Day Weekend, it started in 1969, so this was the 41st meeting. I've been a regular since '87, and except when my mom died in '88, have never missed a gathering since.

It used to be THE west coast gathering for those interested in telescope making, or do-it-yourself astronomy. In recent years, however, the telescope making has fallen off with the ready availability of inexpensive imported optics. While 10 years ago there might have been up to 40 entries in the competition, this year there were 13, with 5 merit awards given out.

There is no lack of vendors, however! For them, having up to 2,000 enthusiasts (1,100 registered this year) attending over the weekend is a great way to showcase their new products. While I didn't recognise any new vendors other than Lunt Optical Systems (solar telescopes), the standard big vendors like Celestron, Meade, Tele-Vue and many others were doing brisk business.


I got my wish by the appearance of Olivier Thizy, a promoter of spectroscopy, who brought a set of instruments to show the solar spectrum to passers-by. He had a new fiber-fed echelle spectrograph that he allowed me to mount my new IR-modified camera to find it's wavelength limits. Shown here are Melinda checking out the solar spectrum in a smaller spectrograph, and the resultant echelle spectrum with the IR camera. Normally, the visible spectrum would run across the bottom of the image, but in this one, the red part of the spectrum noted the end of the visible range, and the longer IR wavelengths increase upwards. Note the blue appearance of the IR limit on top - it shows the blue pixels in the camera have an "IR leak" that tint deeper IR colors blue. Most visible in the spectral bands are dark lines that I think are due to telluric bands from the earth's atmosphere.


Likely the highlight of the conference is the swap meet. Over the years, I've seen most anything astronomical for sale or swap. Since we were staying in town and were up relatively late doing some observing Friday night, we were couple hours late and missed the big crowds and stunning deals, but were still impressed. As an optician, the highlight for me was a nice mirror blank for sale, shown here with owner Jerry. It is purported to be a spare from one of the Landsat programs, and is a fused quartz eggcrate fusing - two sheets with a thin web structure, making it lightweight and stiff, slumped to about F/2. Being fused quartz, it is low-expansion and is little affected by temperature changes. I couldn't resist, and after chatting with Jerry, agreed on a good deal. I see an 18" Cassegrain telescope in my future! Another spectacular table, was of the stony-iron meteor section hoisted here with abundant olivine crystals, looking like stained glass. It was easy to resist this piece with it's $15,000 price tag!


The real highlight of the conference for me, though, is always the one time a year to catch up with similar-minded friends I only see once a year at this event. You can hardly take a few steps before seeing someone else to chat with. It is amazing the contacts you can make over the years, from well-known observers at Palomar like Jean Mueller, to optical and aerospace engineers like Dave Radosevich, and Jack Eastman, shown here with friend Valerie Goff. Of course, Jack not only looks like a character, but is indeed one! He was involved with optical manufacture early on - from Celestron in the early days, to Lockheed -Martin, where he recently retired.


And while revisiting these friends every year is the highlight for me, organizers are slowly changing the event. With interest in telescope making waning, they are working to change it to an observing event. While normally always held on the holiday weekend no matter the moon phase, next year it is moving up to be held on the dark-of-the-moon weekend for dark sky observers. It remains to be seen if this will hold on to attendees, or if registration will continue to slide. For me personally, observing conditions are much better here in Arizona, and I wouldn't make the trip just to observe. If my acquaintances stop coming, I'll likely do the same...

There were an abundance of great talks this year. Highlights for me were mostly historical in nature. On Saturday Tom Johnson, the originator of Celestron talked about the early days of the company. He is shown at left, and also appeared in the ad copy on the right from 40+ years ago. On Sunday morning, there was an amazing talk by Scott Kardell on the construction of the Hale 200" telescope. What was amazing to me, the jaded, reasonably well-read astronomer, is that I hadn't seen any of the dozens of archival images he showed in his talk. Scott also runs a Palomar-themed blog. And of course, another highlight was the Bob Goff lecture, started by his widow Valerie and me after Bob's passing 7+ years ago. This 7th lecture was given by Robert Sigler on the topic of "Glass-Liquid Apochromats", using liquids with unusual optical properties to improve telescope performance with normal or inexpensive glass. With high performance apos costing upwards of tens of thousands of dollars, designs using liquids can provide high performance with reasonable cost...

RTMC has always been a part of my Memorial Day Weekend, but it remains to be seen if that relationship will continue into the future!