Third Time is a Charm: Observatory in Southern California
I can remember the first telescope I got as a birthday gift when I was in 3rd grade. It was a 3 inch Gilbert reflector. That telescope and my first years of using it began a lifelong interest in astronomy. Except for a period of 8 years while pursuing my education, I have pursued my hobby with a passion and have gone through a variety instruments until finally settling on a Celestron 14. My interest in photography began early as I attempted to photograph the moon (mid-sixties) followed by piggyback photography (late sixties). I continued this photography interest for many years as I lugged around a C-11into the corn fields of Indiana and the cow pastures of South Carolina. It was soon realized that with the purchase of a home, an observatory would be welcome relief.
The observatory seen in the figure is the third such one I have built during the past eight years. The first was built in South Carolina with Jack Hall, a fellow amateur, who also built one of similar design. We examined designs which had been published before and decided to go with the classic roll off roof you see here with sides anchored to a 5 inch re-inforced concrete slab and the roof on four inch wheels and secured on the inside with adjustable gate latches. It only takes a few minutes to unhook the latches and roll the roof back for a night of enjoyment under the sky. Since I have always had a telescope with a fork type mount, the orientation of my original observatory was in the north-south direction with the roof rolling off toward the north. This resulted in the roof blocking part of the northern sky, a part of the sky not accessible with fork mounts. This worked so well during the three years that we lived in South Carolina that when we moved to central Indiana, the identical type structure was built again. However, disaster was on the horizon! Within a few months of first light, we were hit by a tornado. You can imagine my horror, when my family and I came out of our basement to discover the roof of the observatory scattered over several acres! Miraculously, the telescope was still standing, dripping wet. The winds had torn the roof up and over the telescope. The optical tube was sent back to Celestron for cleaning and new coatings while eyepieces, drive correctors and all else such amateur essentials were simply cleaned of "tornado debris" and allowed to dry. One might be tempted to say "if only we had stayed in South Carolina". Not so! A few months later, coastal South Carolina was hit by hurricane Hugo and we found out afterwards that my old observatory likewise had its roof torn off. Three years in Indiana and we were off again, this time for southern California. As with our previous home purchases, I drew a forty mile radius circle around the largest city in the area (San Diego) and told my wife and real estate agent to look outside this circle. Fortunately, my wife Ellen understands and enjoys country living and gardening which comes with it. However, she still cannot hear the stars calling out to me on a clear night. We ended up in the northern part of San Diego county only a stones throw from Mount Palomar. Once again the same observatory design was used with some variation. We live on the side of a rather steep hill which faces north. This forced me to tuck the observatory between rows of our orange grove in an east-west direction with the roof rolling to the west. By now I have gotten pretty good at putting these structures up and within a week of having the slab poured, I was set up and in business. The total cost of the observatory is around $1000 including the concrete and hiring someone with a back hoe to carve out a flat area from the hill. While I may have left tornadoes back in Indiana and hurricanes in South Carolina, California has earthquakes and we often feel minor shakes. Even though my C-14 is on a tripod within the observatory, it is firmly bolted to the concrete with bolts. The skies at my observatory here in Valley Center are the best I have had of the three. They are not necessarily the darkest although my limiting visual magnitude is 6.5 with the lights of Los Angeles very low in the northwest (80 miles distance) while San Diego is 50 miles away toward the southwest. They are, however, exceptionally steady. Being only 13 miles from Mount Palomar and the Hale telescope, my site benefits with the same steady air which Palomar enjoys. Except for the occasional Santa Ana winds that blow off the deserts from the east, the stars just don't twinkle here and I am able to enjoy much more time at the telescope because of the many clear nights. Further benefits of this site over previous ones is the lack of mosquitoes and very low humidity. I've been spoiled!
As I mentioned above, I always had a special interest in astrophotography. In the sixties, I used tri-X and plus-X films while in the later seventies I used the old spectroscopic films. In the early eighties when hyper-sensitizing of film was just beginning, I began experimenting on my own. My profession (pharmacologist) always allowed me to have easy access to good vacuum pumps and hydrogen gas at my various places of employment. I established my own system for hypering film with pure hydrogen gas which produced the desired level of sensitivity and after experimenting with a variety of films settled on tech pan 2415 (like everybody else). I found that I could hyper a 6-8 exposure roll of 2415 in the canister(no need to spool it out) in 8 days in pure hydrogen at room temperature. By using a large glass dessicator with a vacuum port, I could hyper 15-20 rolls at a time. I simple placed the film in the dessicator, pumped out the air for about 15 minutes and then using a balloon which I had filled with hydrogen, bled the gas back into the evacuated dessicator until ambient pressure was obtained. After 8 days, the film was removed, tested and stored away in a freezer until used. The film prepared this way was good even after 2 years storage. For guiding I have used a Lumicon giant easy guider. As the name implies, it is big and made guiding and finding a guide star easy. In addition, in conjunction with the large focal reducer, it provided an unvignetted field at f6.5 over the entire 35mm film frame. The appearance of autoguiders (ST-4) in early 1990 was a God send for those of use doing 60-120 minute hand guided exposures. While it made astrophotography much easier, it also points out the shortcomings in your drive system. The drive of my C-14 was incapable of keeping the guide star on the small CCD chip, so my initial attempts at autoguiding were fruitless. A Byers C-14 retrofit solved this problem and soon the ST-4 became the workhorse of my astrophotography endeavors for the next 5 years. Using this system on a steady night, I could typically guide within a circle of 4 arc seconds for an indefinite period of time. The use of a computer interfaced with the ST-4 greatly aided in finding a guide star and monitoring the guidance and sky conditions. Sky fog limits my exposures to no more than 120 minutes when working at f6.5.
I never actually took an image of an object using the ST-4. For me, it was simply an aid for the guiding of the emulsion. The small field of view and "grainy" appearance of the pictures obtained was no match for hypered 2415. However, I did follow developments as they were occurring in the CCD camera area thinking it only a matter of time and the resolution would increase. When Meade announced their new line of cameras based on the Kodak chips with 9 micron pixel resolution, I began to get very interested. Shortly thereafter, SBIG announced their equivalent version with a very important novel feature: an additional chip which allowed for simultaneous imaging and autoguiding, I new the time had come to give this new imaging technology a try. This web page shows some of the highlights.