REVIEW : Skywatcher 6" F=1200mm Refractor
6" SKYWATCHER Refractor on EQ6 mount. Focal length= 1200mm
Shown with 70mm, F= 900mm secondary/ guide scope, 9x50 finderscope, and Telrad.
This telescope is not really meant for deep sky observing, although brighter objects such as galaxies M81 and M82, and globular star cluster M13 don't look too bad considering the 6" objective lense. The images are dimmer, but sharper than those I get through my 10" Newtonian reflector with the same focal length.
The metal focusser will accept either 1.25" or 2" eyepieces, and the travel will also lock if desired. This telescope also comes with a good 9x50 finderscope. Aiming it is quite easy and is done by adjusting 2 thumbscrews on the mounting bracket 120° apart, while the 3rd point rests on a spring loaded support. The finderscope and mounting bracket slide into a channel bracket and tighten with one large thumbscrew, enabling quick removal and installation. I have found that the finderscope keeps it's alignment well as long as the bracket is inserted all the way into the channel and held steady while the thumbscrew is tightened.
The lunar and planetary views are quite nice, even at higher powers. The 8:1 focal ratio doesn't create much false colour, but what little there is can easily be filtered out. For this purpose, I use a Baader Fringe Killer to eliminate the unfocussed colour in the violet range, along with a Baader Neodymium (Moon and Skyglow) filter to offset the greenish tint caused by the Fringe Killer. Since the objective lense is large to begin with, the filtered image is still pretty bright, and it is very sharp. The colour is not true as a part of the violet range has been filtered out, but the sharper image is worth the compromise.
The first time I tried this scope out was in January a few years ago. While looking at Jupiter I was impressed with the clarity of the cloud bands and the orbitting moons. I saw what I thought was a spec of dirt embedded in the coating on my brand new 6mm Radian eyepiece. I noticed that the spec remained stationary as I rotated the eyepiece in the focusser. That spec turned out to be a shadow from one of Jupiters moons on the planet's surface. The planet Saturn was equally impressive. The image was very sharp, and Cassini's ring division looked clearer than I had ever seen it. The moon looks fantastic through this telescope on nights of good seeing. Every detail shows up, and it takes a lot of magnification before the image even starts to look grainy.
This telescope is heavy (30 lbs,) and requires a heavy duty mount. I have used it on a CG5 mount before, but it just feels a little sturdier on the EQ6, not to mention the fact that it looks more impressive. If I had a permanent observatory, I would like to have something like a 6" F12 or possibly even an F15 refractor in it just to see how it would compare to this. It would probably still be a lot cheaper than a good 4" Apo (NOTE-I have since purchased a 5.2" apo triplet instead).
-----------------------