D&G 6" f/12 Refractor

D & G Optical 6" F/12 Refractor
By Tom Wade

I'll admit that when it comes to telescopes, I'm not very objective (sorry I couldn't resist). I love refractors. It all began in the early 70's when I was making my first serious telescope purchase. It boiled down between a 4" F/15 Unitron refractor and a strange stubby-looking telescope. I chose the Unitron because I figured this telescope company would be around forever and the other company, I think their name was Celestron, probably wouldn't last long, after all they were painting their telescopes ORANGE.

So thirty years later with my love still intact I decided to get something bigger. So about a year ago I purchased a 6" F/12 refractor (O.T.A.) from D&G Optical. (To me this scope is simply known as "My Baby" which is also the term of endearment I use for my wife, but when I'm referring to her I use my Barry White voice. Or is it the other way around?)

By the way, I have been an observer for nearly 40 years. I have owned nearly 20 telescopes and unfortunately I have had no connection with any telescope manufacturers or suppliers.

After a five month wait, the telescope arrived. My first impression was "Boy, is this big!" Its length without the dew cap installed is 68 inches; with it, 76 inches. Its weight without finder, rings and mounting plate is 26 lbs. Knowing that the mount needed would have to be substantial, I purchased beforehand a Losmandy G11 with an extended pier with rings and mounting plate by Parallax. This combination works extremely well.

The second thing that caught my eye was the rack and pinion focuser. The focusers on the D & G telescopes are made by Astro Physics. It is their 2.7 inch model which has a full 7 inches of travel. It is also baffled. Their focusers are "works of art," by far the best focusers I have ever seen used.

The lens was shipped separately. It came mounted in a machined push-pull adjustable cell. The lens is an air-spaced achromat doublet, fully-coated, pitch-polished and individually hand-figured. The cell has 3 collimating adjustment screws. All I needed to do was to attach the lens cell to its corresponding mounting plate on the tube in the orientation marked by the factory.



Having had the opportunity to use this scope numerous times, this is my experience:

Several things became apparent very quickly. First, the background sky was very dark. The background looks dark in any telescope, but there seemed to be an extra "blackness" to the sky that was very noticeable. The images of the stars were pinpoint right to the edge. When focusing the image, objects snapped into focus. There was no need to search and find the true focus. There was no softness to the image. Since I bought this scope to use mainly as a planetary and lunar scope, I tuned it first to Jupiter.

It is here the scope excels. The Galilean moons appeared as resolved spheres and not just points of light. On the planet itself, the north and south equatorial bands were not bands at all for they were both resolved into a series of festoons, garlands, ovals and the like. The telescope seemed to excel in revealing even very slight differences in contrast making it possible to observe disturbances in the various belts and zones from the equator to the polar regions. The first time I observed Jupiter through this scope, I was mesmerized by what I was seeing. I just sat there for the longest time looking at it. I couldn't take my eyes off it.

Saturn was equally impressive. Numerous faint belts could be observed from the equatorial region to the North and South poles which were noticeably darker. The Cassini division looked as if it were drawn by a draftsman's black pen. The rings showed slight variations of shading.

False color was not noticeable on Jupiter nor Saturn and only very slightly on Venus. It almost seems unfair to the scope to mention this because it was very slight. (By the way, upon observing Venus, I was able to detect an irregularity on the terminator which I had never observed before. I know that reports of these go back the 1600's. Has anyone reading this observed them?)

The optics of this scope I would have to rate as exceptional; by far the best I have ever owned and I own a lot (the exact number is a closely guarded secret lest my wife should read this).

Things I Like:

• First-class optics
• Precise rack and pinion focuser
• Plenty of attention received at star parties

Things I Don't Like:

Its size does present a challenge, but I can hardly criticize it for this as it is its sized that enables it to do what it does so well.

Concluding Remarks:

I had an opportunity to take "My Baby" to a star party at a dark observing site called Hickory Hill once used by the St. Petersburg Astronomy Club in Florida. I had set up the telescope and started observing when a group of about 6 people who lived in the area and had seen the telescope and decided to come by and ask if they could look through it. I said, "Sure," and I pointed the scope at Saturn. The first woman (perhaps in her forties) leaned down and looked. She looked at Saturn for what seemed like a very long time and in complete silence. Finally she straightened up, looked at me, her eyes glistening as if tear laden and said "It's so beautiful." It was a moment, I'm convinced, she will remember as long as she lives. And when I think about this and the impact the universe can have on one when seen through a telescope of this quality, the trouble and effort it takes to set up "My Baby" seems in retrospect, so trivial.

- Tom

P.S. Two years after I bought the Unitron, I did by one of those funny orange telescopes. I'm so glad that at least they and I are still around.