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Celestron 6" Refractor and Skyview Pro Mount


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Review of a Celestron 6” Refractor and Skyview Pro Mount

Background and qualifications:

Astronomy has been my main hobby for around 48 years. As a kid my parents gave me the usual 60mm Sears refractor, 50 mm Tasco spotting scope and the 3” reflector with the square diagonal. They were often used and abused! Having 4 kids and a poor paying job I built an 8” Dob with a second mirror from Coulter Optical in 1983. The “Bargain Bucket” cost me $75. It is still being used today, though it has been rebuilt 3 times and needs the mirror re-coated soon. Along with the “Bargain Bucket” I used a Celestron C4.5 to look at the planets. A Meade DS-90 and an ETX 90 RA and numerous “garage sale specials” round out the stable of telescopes along with the Celestron 6” Refractor that is being reviewed here.

The AAVSO is one organization that I have belonged to off and on over the years. The only local club I belonged to was the Astronomical Society of Kansas City, though I did give a talk on “Dusty Asteroids” at the Astronomical League Convention in Salt Lake City. I have presented 4 papers at the Mid-America Regional Astrophysics Conference in Kansas City and a paper at the AAVSO Spring meeting in Tucson, AZ. I taught Astronomy at Mohave Community College, in Kingman, AZ as an adjunct for 4 years. Our field trips to Flagstaff were legendary! Including the Van that caught on fire, but was driven back to campus 2 days later.

We have lived all over the country! From Arizona to Montana, Florida, Missouri, New England, Colorado, a summer in Washington, graduate school in California and now we live in southern New Mexico, though my kids live in the Midwest. So I believe I am somewhat of an expert on regional “seeing” conditions!

Overall, my many years of experience with locations, different kinds of telescopes and astronomers, qualifies me to be a good judge of equipment.

After buying a used Celestron 6" Refractor and Skyview Pro mount in November 2008, my two boys in OK braved the weather and brought it with them when they came home for Christmas. The Optical Tube Assembly is one year old and the Skyview Pro is also less than 2 years old. Here is a short review.

Optics:

The optics are excellent! Though the telescope was slightly out of colmination tightening up the tension screw on the focuser took care of the problem. Stars in and out of focus are almost textbook. For most of my observing I use a Minus-V filter from Celestron. This controls most of the Chromatic Aberration. Even Venus shows detail on the disk with only a small fringing of purple. There is no CA when you look at fainter objects. Star images are round all the way to the edge of the view. One of the things that I found interesting is that the colors of stars seem to be much easier to see.

Mechanical:

The focuser needs work. I took it apart and used some “Oops!” solvent to get rid of the grease. Since it is winter I just decided to go without a lube and see what happens. After a couple of weeks of use I’ve decided it could use some lubricant and that will make the focuser much more user friendly. Though it is a bit of a chore I have used the stock focuser to CCD image. Without a fine focus you just have to spend a little more time getting it right. Over all it is good for visual work and acceptable for imaging.

Mounting:

I have heard horror stories of jiggling views and telescopes to big for their mounts. In many posts it mentions that the EQ-5 or Skyview Pro mounts are just not stable enough for a telescope of this weight. So far that has not been the case with my set up. Though it does take a short time (3-5 seconds) to settle down I do not find this objectionable. In fact with the True Track drives that I use you have to tighten down the axes knobs to make it track and I have not had any problem of losing the object or shimmy. Over all this is a strong combination for the price. I kind of wondered how objective many of the posts are when they say an 8” Newtonian will work on this mounting but a 6” refractor will not. Since the Newtonian is as big and just as heavy it does not make much sense.

Ease of Use: If you break it into 3 pieces it is easy to move, OTA, tripod/head and weights. You can move it in two parts but I find that to carry all that weight is a little hard on my bad back. Since the objective lens is the heaviest part of the tube you need some extra weight near the focuser to get the telescope to balance towards the front. If you don’t add some weight you have trouble reaching the mounting controls. I added a 10X50 finder and a heavy metal magnet from Wal-Mart. When you add these two items along with an eyepiece and diagonal it begins to balance closer to the center. When the flip mirror and CCD are added it then balances very well.

Stars:

Good colors, crisp focus, mount settles down after 3-5 seconds for very good views. I really like the lack of Coma! My Dob is fun but this really has better optics (of course my dob cost me 70 dollars to build in the 1980's! So it does not have the same quality optics.) Star clusters are amazing! The view is outstanding all the way across the field of view. Rigel could easily be split with a 7.5 plossel eyepiece.

Deep Sky Objects:

I was very impressed with M42, M81, and M82. M1 was visible but there was not much detail to be seen. All of the others were excellent. Views were slightly dimmer but much clearer than my 8” Dob. Could see amazing detail in M42. The trapezium was very clear and separated. At higher powers the two extra stars in the trapezium were clearly seen. The nebulosity in M42 looked like milk spilt on black velvet.

Planets:

Venus and Mercury are the only planets that I have viewed so far. However, these are a good test of a scopes optics because of the brightness. Venus was very clear and crisp. The terminator was straight and the outline of the planet was very distinct. The body of Venus was white with just a touch of purple fringing around the outline. Seeing was poor but had good view at around 75-125 power. Mercury showed the phase quite well but seeing was really wretched. Mercury was observed at around 75 power as well. The seeing would not support more than this. This happens a lot since I have to look out over roofs to see Venus and Mercury from my backyard. If a low F ratio refractor can do this well on these two planets in poor conditions, then all of the other planets should be outstanding.

Additions:

The Skyview Pro did not have a pole finder or drives. True Track Dual Axis drives from Orion were added along with an Orion pole star finder. My past experience with a computerized scope has been pretty frustrating. With a busy schedule and limited observing time, every minute spent in setup is a minute lost to observing. I found that I was spending most of my observing time getting aligned or trying to keep alignment. There is something to be said for easy.

The True Track only took me a half hour to install. The polar finder took even less time. However, the polar finder was hard to adjust until I took it apart and saw how it worked. Three screws suspend the reticule. It is not like a normal finder so if you want the reticule to move downward you loosen the bottom screws and tighten the top. On most finders you have to do the opposite. There are several websites with good articles on how you install and adjust the polar finders.

Setup takes about 5-7 minutes (It takes me almost as long to plug in the extension cord, set up my laptop and hook up the true track power supply as it does to polar align and mount the scope!). After bringing the tripod out, a quick look through the polar finder aligns the scope quite quickly. Just a note. It is much easier to set up the polar alignment before you mount the scope! In fact, it is really quick if you take off the weights and then adjust the mounting while looking through the polar finder. Since the polar finder is not illuminated you have to shine a red flashlight at an angle in the front of the polar scope in order to see the reticule markings. I use a penlight covered by my fingers. This keeps it “red” but I still have a white light to use when I break down my scope.

With the true track drive you can start observing just as soon as you get your scope attached to the mounting. This is a plus when you have limited time. You center the object, tighten down the axis knobs and then start observing. Most of the time, with a 16mm eyepiece or larger, it will keep an object centered for over 20 minutes. At higher powers it will track for 20 minutes but moves across the field of view some. If you need to re-center or look around a field of view, you just use the paddle to move. To move it to a new target you loosen the knobs move it, tighten the knobs and you are ready to go again. Some would find this constant tightening and un-tightening to be objectionable but I find it much simpler and it lets me be in control of the scope and not a computer.

An AstroTech 1 ¼ inch dielectric diagonal was also a good addition. There is no comparison between the stock Celestron diagonal and the AstroTech. The stock item has less than 90% reflectivity and the AstroTech around 99%. This is like adding additional light gathering power to your telescope. It is well made and it is definitely a precision part. With the length of the tube and the height of the mounting a diagonal is important to observer comfort.

The last item added so far is a 10X50 finder scope. I purchased a finder on ebay from “The Telescope Warehouse.” Though it is not illuminated it is an excellent finder. A finder bracket was also purchased from another company (I missed the ad for a finder bracket at The Telescope Warehouse!). This setup was not stock so I just super glued the bracket to the finder mount. Works great and should outlast the telescope!

Overall, especially for the money I paid, I am very pleased with this scope. There have been many posts on the boards indicating how enjoyable this scope can be. The coma free views really enhance the experience, especially on stars and planets. With care this can be all the telescope you will ever need for a life time of viewing pleasure.




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