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Skywatcher 102AR-AZ4 Review

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#1 chgomonitor

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Posted 09 April 2009 - 06:54 AM

Skywatcher 102AR-AZ4 Review
By: Ted Moran

I suppose any review is largely dependent upon the author’s experience and expectations and mine is certainly no different. Aside from a few occasions of using friend’s telescopes and a handful of joyful observatory visits nearly all of my sky viewing has been done with department store grade 60mm alt-azimuth refractors with 0.965 inch focusers and eyepieces. And almost always from very urban or more recently, suburban skies.

From the beginning I’ve always preferred refractors and almost immediately contracted aperture fever, though I never pursued obtaining a larger instrument. The combination of locally horrible sky conditions and a lack of large scale income always made the investment very hard to justify. But I’ve been persistently haunted by various astronomy guide book author’s description of what can be seen with a “fine four inch refractor”.

A couple of years ago I found a renewed vigor in my amateur astronomy interests which I initially addressed by obtaining some decent binoculars, including a pair of 20x80’s. I was still using a 1990’s vintage Celestron C60 refractor and increasingly feeling that I had simply outgrown it. Combine the market emergence of fairly inexpensive (mostly Chinese) larger refractors with 2008’s tax refund check and my wife and I made the decision to finally upgrade.

I did a lot of very careful market research, including endless hours spent pouring over the reviews and forums at Cloudynights. I’m long accustomed to the hideous Chromatic Aberration delivered by cheap, department store grade Achromatic refractors. I do almost no astrophotography, all my observing is visual with some limited (horrible) sketching attempts and I enjoy the star hopping challenge in my suburban skies. My main interests are lunar and planetary but I’ve also been enjoying attempting some limited deep-sky object observations as far as the local light pollution will allow. My locations and facilities are fairly limited to the back yard and driveway so grab and go or at least a quick setup and limited storage are also factors for us. Finally, my vision is, well, really quite poor.

I know that fast, short apochromatic refractors are all the rage these days and some of this equipment is extremely impressive, to say the least. But I really had to look at my observing habits and priorities. I knew I wanted a refractor with enough aperture to deliver fairly high magnifications with not too small eyepieces. I wanted to spend my limited money on glass and not on fancy mounts. Being willing to live with Chromatic Aberration and my local skies limiting hard core deep sky observing helped me make my final decision. I decided on the Skywatcher 102AR-AZ4 (four inch Achro) refractor.

http://www.skywatche...-telescope.html

I ordered directly from the Skywatcher USA web site. I also ordered their short model 1.25 inch Barlow;

http://www.skywatche...-2x-s31401.html

I was not without concerns. I could find no reviews of this particular model telescope anywhere, though some U.K. web sites were giving the alt-azimuth mount itself very good early reviews. How bad would the Chromatic Aberration really be? What about overall build quality? Was this model even really yet available? Having zero experience with Plossl eyepieces, let alone 1.25 inch eyepieces or (gasp!) a two-inch focuser, a red-dot finder, Teflon bearings, dovetail plates and an awful lot of this other great sounding stuff left me more than a little concerned. When I didn’t quickly get a shipping announcement e-mail from Skywatcher (I did get an order confirmation instantly) I assumed it would be a long wait on that proverbial slow boat from China.

Surprise! Only 5 days later I awoke to find a very large cardboard box on my front porch. Hooray! The Barlow arrived in a separate, much smaller box. The intact telescope box was marked “Celestron” (gasp! wrong model?) and was tightly double-boxed. Inside, more boxes containing all the various sub-assemblies; OTA, mount, head, optics, etc. I excitedly but carefully unpacked and assembled everything. Hooray! It IS the Skywatcher 102AR-AZ4 inside!

I was instantly struck with two first impressions, both of which have totally stuck. One, this thing is quite a bit bigger and heftier than I had thought and Two, the build quality, workmanship, craftsmanship and overall engineering of this thing are very, very impressive. The fit and finish leave little to be desired and everything works and goes together very smoothly. Sadly, it wasn’t until a week later while cutting up the boxes for recycling that I discovered the owner’s manual folded up between two box layers. The manual isn’t the world’s greatest, it suffers a little in the translation and it is of the generic style, covering 6 different Skywatcher alt-azimuth models. I could have used one more illustration covering mount assembly, but I figured it out without the manual fairly quickly. I’d also suggest Skywatcher consider including some sort of beginners guide on amateur astronomy.

The gold fleck on dark blue paint scheme on the tube looked a little on the cheesy side on the web page. Not so in person, it’s really quite striking and attractive and very well applied.

Of course I immediately tried peering through my front door window at telephone poles and trees in my neighborhood. I discovered I couldn’t get a good focus on anything much under 100 yards away but that night I was greeted with a couple of hours of decent suburban night skies.

First light was Venus at about 60 percent crescent phase. Wow! Nice and big! What a difference between a four inch refractor and a two point four 60mm! Like night and day. Yes, no shortage of Chromatic Aberration, but much less than what I was anticipating. The tips of the limbs showed some obvious yellow and purple fringing glows. But actually a good deal less than the Celestron and other 60mm refractors I’ve used and what I’d describe as more controlled CA. I can definitely live with this, what a relief!

Next up, the Orion Nebula. I popped in the 25mm Plossl and swung the scope around. Wow! It’s the real and true Trapezium! There it is! I thought I’d spotted it many times in the past but instantly I realized that I’d never seen it even once before. The four primary stars perfectly resolved and separated floating awash in the nebula’s well defined gassy glow. Amazing! I can even see the dark lane above it. (No, I still haven’t caught five or six, but I’m a very happy suburban camper). I was particularly impressed with how much better this telescope reveals the nebula itself compared to my 20x80 binoculars. That extra 22mm’s of glass does a lot, despite the much slower focal ratio. A nice half moon was up so that was next.

Again, wow. The 25mm Skywatcher supplied Plossl yields a razor sharp, high contrast, gorgeous, field filling lunar image. Far exceeds my expectations. Adding the Barlow really brought out the details while retaining focus and contrast. I never realized just how poor the plastic lens 0.965 Barlows I’d been using all those decades really were. Breathtaking difference.

I switched to the Skywatcher 10mm Plossl eyepiece. Slightly less impressive performance than the 25mm. Not a bad view by any means, but just a hair less sharp than the 25mm and a good deal less contrast. It’s what I call just a little bit “mushy”. Still, a world of difference using 1.25 eyepieces as compared with 0.965 diameter ones. I tried Barlowing the 10mm just for kicks, but local seeing conditions didn’t support that high a magnification (x200) and I was greeted with mostly mush.

Both of the Skywatcher eyepieces have acceptable eye relief for me, which I’m pretty sensitive to, and both are sharp to the edges of the field with no distortion that I can detect. The 25mm has an excellent, very wide viewing opening. The 10mm is a great deal more challenging but still vastly better than my old 6mm 0.965 orthos and kellners.

I can’t say enough good things about this AZ4 Skywatcher mount. I’m an old wooden tripod guy so this was a big change for me. I was particularly concerned with what I’d read about vibration and steel tripod mounts. If you like alt-azimuth mounts, you’ll love this thing. Mechanical build and alignment are excellent. Both axis employ very smooth Teflon bearings and use large, plastic hand wheels to lock and adjust tension. They work very, very well. It does take a bit of experimentation to find just the right tension settings but once you get there you are rewarded with buttery smooth eyepiece end hand slewing in both directions. Good tube dovetail mount balancing practices (easy) make things even better.

A hefty, pronged steel accessory holder tightens on a central threaded shaft hanging through the tripod head. This also attaches the mount to the tripod. Y-Fingers on the three prongs of the accessory holder mate up against the insides of the tripod legs. Careful but easy tightening of the thumbwheels on the shaft creates tensions which make the mount even more solid. It’s a rock solid mount and does not pick up any external vibrations from passing vehicles, trucks, etc. Excellent isolation. Eyepiece end induced vibrations dampen out totally in one to two seconds, depending on orientation and tube balance. The sturdy slewing arm can be attached to the mount in one of two places, both above and below the tube. When attached in the low position the arm will collide with tripod legs when the telescope nears zenith point angles.

The accessory tray has five 1.25 inch holes and two 2 inch holes for eyepieces, filters, caps, etc. One of the 1.25 holes is partially obstructed by the lower mounting shaft thumb wheel underneath, but it still works for end caps. It is a solid steel casting, very sturdy. The mount head has setting circle like markings for degrees of azimuth and elevation.

Each tripod leg has one telescoping section which extends about 16 inches. Height from the ground to the pivot bolt center of the head assembly is 54 inches fully extended. This allows for a limited degree of height adjustment, but in practice I keep my legs fully extended all the time. The legs are well secured by thumbscrew bolts, but be careful not to under or over tighten them. The 102AR is the longest tubed telescope Skywatcher markets with this mount and in truth; it is a little too short for a telescope of this dimension. You’ll find yourself sitting on the ground at times. I don’t mind at all and I keep a hefty piece of corrugated cardboard handy for these occasions. I feel it’s an acceptable trade off between height and the extreme stability this mount offers in this price class. Each leg is tipped with a well designed plastic foot spike which by some miracle come out of my yard mud easily and still mostly clean. They work nicely on concrete as well.

The legs appear to be some sort of stainless steel tubing, quite thick and sturdy. I am a little concerned about how well they’ll stand up to dewing moisture over time.

The telescope optical tube is mounted to the tripod head using the familiar mounting rings and Vixen style dovetail plate. It’s secured to the head using a single, large thumbscrew. While this enables easy tube balancing adjustments it is also none too secure. I’d encourage extreme caution when mounting, demounting and adjusting the tube to avoid the potential catastrophe of the tube falling to the ground. Be careful! The dovetail plate / mounting ring assembly is very sturdy and well made. The rings feature male and female mounting points for limited accessory attachment use.

The mount has no slow motion controls of any kind. Reaching the tension adjustment knobs can be challenging depending on how long your arms are and how far out the focuser is adjusted. Overall though, I rate the design, performance and slewing actions as all excellent, far exceeding my expectations.

The red dot finder is a new thing for me. Initially, I didn’t care for it. After a few tries I’ve finally got it aligned highly accurately now and I’m getting a lot more comfortable with it. The hearing aid style battery is rated for 480 hours. I’ve already left it on for 24 hours once by mistake with the scope stored outside at 30 degrees Fahrenheit and it’s still working fine. It’s easy to use while remaining seated behind the eyepiece, which is nice compared to a conventional finder scope. Its dimmest red dot setting is still a bit too bright. I’m considering substituting an 8x50 illuminated reticule finder as an upgrade.

The dew shield is coated metal and is of the press to fit variety, but fits quite well and snug. The dew shield end cab cover also has a sub-cap to enable limited aperture use when desired.

I know the standard 2 inch Synta focusers have something less than a perfectly stellar reputation among higher end scope users here at Cloudynights, but I have to say that I’m very happy with it. It is an enormous step up from the bumpy, draw tube junk I’ve used in the past. It will accommodate both 2 inch and 1.25 inch eyepieces and has a little over 5 inches of travel. In that last inch you will encounter just a tiny bit of side to side wiggle slack, though. The 1.25 eyepiece mount has a single securing thumbscrew; the 2 inch position has two. Using very high power eyepieces does require some very fine tuning, slow focusing efforts but it works for me. I’ve had the scope out for hours at 10 degrees Fahrenheit and none of the lubricants in either the focuser or the mount show any sign of stiffening up in the cold, wonderful. The top of the focuser mount has a bar shaped extension with a couple of screw holes and one thumbscrew for an unspecified “accessory”, but there is only one real dovetail opening for a finder scope, etc.

My biggest single criticism of this scope is that Skywatcher includes a 1.25 inch, 45 degree erecting image roof prism instead of a real 90 degree diagonal. I suppose they are trying to keep costs low while still appealing to the terrestrial viewing crowd. In fairness, the erecting prism does seem to work fairly well without introducing too much optical “mush”, but I’m shopping for a high quality, 2 inch mirror diagonal.

The objective lens assembly appears to be precisely engineered and well designed. It’s held in its somewhat complex looking mounting ring with what appears to be an old fashioned C-style steel bayonet ring fastener. I haven’t worked up the probably ill-advised “courage” to attempt to dig deeper to see about collimation adjustment possibilities, but it does look like there’s something along those lines down in there. The scope arrived in what appeared to be near perfect collimation so I haven’t been so inspired. Perfectionists may differ… The lens coatings look beautiful, a nice shade of mellow blue. I can see at least a couple of tube internal baffles and everything inside is a wonderful shade of jet flat black.

I’ve had the scope out in the yard a half dozen times over the past few weeks. It far, far exceeds all my expectations in terms of both optical and mechanical performance. Although I bought it almost exclusively for lunar and planetary work its actually also a great performer on deep sky objects, at least to my tired and light polluted eyes. I’m sure it’s no Apochromatic on DSO’s but I’ve already found a half dozen open clusters that I’d searched for over the decades with 60mm scopes and they are all breath taking. Quite surprisingly good for an F/10 system, in my opinion. Stellar color presentation is excellent. I’m seeing well into 10th magnitude in suburban skies where the visual limiting magnitude hovers around 4 on good nights. I know, I should be doing all sorts of field of view measurements and checking resolution against test doubles, etc. I’ll eventually get around to that stuff but I’m having too much fun for right now. I can tell you I got down to under 4 mile features on the half moon tonight under really lousy conditions. I’ve got about 40 years of lunar observing under my eyelids and I can tell you, this is a great lunar telescope. No distortions, great flatness, very sharp and high contrast.

I was planning on getting a high power planetary and a low power, wide field eyepiece as upgrades. For the high power I was figuring on the old 50x to the inch of aperture formula and thinking 4 or 5 mm. After trying the Barlow out on the Skywatcher 10mm Plossl I re-thought my plans, my local seeing conditions are simply never that good. I went with 40x to the inch and got a 6mm TMB planetary from Astronomics, instead. It works very well with this telescope optically, but requires racking out the focuser to the point where I’m getting some focuser wiggle – so I’m using the erecting prism with it for now to take up some focuser travel. I might try some focuser rack screw adjusting to see if I can tighten things up just a tad.I’m considering the Williams Optics 40mm 2 inch SWAN eyepiece for DSO work.

If you, like me, are an old time 2.4 inch alt-azimuth refractor guy and you’ve always lusted after a bit more telescope I cannot recommend the Skywatcher 102AR-AZ highly enough. Trust me, you don’t know what you’ve been missing all those years – it’s really an amazing step up. This is one heck of a lot of telescope for 400 bucks. The only real negative I can find is that it is a good deal heavier and bigger than I had pictured, not really in the quickie grab and go realm. Still though, it breaks down very easily and stores nicely. I keep the head attached to the tripod and just take the tube off at the dovetail rail. Two trips in and out in under ten minutes and I’m up and running. With my small house and narrow doorways I’m actually glad I didn’t opt for anything much bigger, a 5 or 6 inch refractor would have been a lot more challenging. Set up it is heavy but I can still pick it and maneuver it around the yard and driveway with one not very strong arm, it’s pretty well balanced when setup, overall.

Well, like I started out with, I guess reviews and satisfaction largely hinge on individual expectations and experience. From where I’m coming from, this is a great telescope. Your results will likely vary, but I’m happy as a clam.

Happy Sky Scanning! - Ted

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#2 chgomonitor

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Posted 09 April 2009 - 07:18 AM

I've since added;

-2 Inch dielectric 90 degree star diagonal, excellent.

-38mm 70 degree 2 inch wide field eyepiece from University Optics. Wouldn't quite reach focus with the stock focuser arrangement - just 3 or 4 mm's short. But it plays very nicely with the diagonal in-line. Love this eyepiece, it's not sharp right to the edge of the field but it performs good enough for me. Framed the Beehive with it last night gorgeously.

(Note: The diagonal and 38mm UO combination make for some major added weight. Tripod head dovetail adjustment alone won't balance this combo. I'm going to move the OTA forward in the rings a few inches).

-A very inexpensive supposedly >4.99 Mw green laser I bought off of an Amazon seller and a plastic green pointer mount from Hotech. I like the mount but I can't see this laser's beam in my suburban skies - at least not with the moon out. I'm reserving the verdict until Spring pollen fills the air and I get to try it out under slightly darker skies.

I'm still looking at finder scope upgrade options. Skywatcher makes an inexpensive 9x50 add-on, but I suspect I'd prefer a right-angle, illuminated cross hair model.

I flashlighted down the OTA and there's a bunch of baffles down deep in the tube, think I spotted at least 5, maybe 6 or more.

Using heavier eyepieces and sliding the OTA forward in the tripod head's dovetail to balance it really improves the ergonomics, making the somewhat short tripod much more user friendly. I'm spending a lot less time sitting on cardboard.

I still catch myself reaching for non-existent slow motion controls, but in practice the slewing actions of the mount can be so finely tuned that I'm (slowly) getting used to not having them.

My wife said to tell you guys she loves the view of her favorite (Saturn) in the 6mm TMB. I do, too.

Bring this scope inside from a damp, freezing cold Chicago Winter night and you run into some serious post-observing dewing issues, but I'm dealing with. Lots of patient drying out follows.

Happy Sky Scanning! - Ted

#3 Patricko

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Posted 09 April 2009 - 09:05 AM

Hi Ted, great post! I realy enjoyed reading it.:goodjob: BTW, the focuser wiggle can be adjusted out by tightening the small allen screws on the top of the focuser (there should be two on the top side of the focuser).

#4 mathteacher

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Posted 09 April 2009 - 09:33 AM

Ted, thanks for the very detailed report. I've been wondering about the AZ4 mount. It seems SW has gotten it right. Lots to be said for a simple, functional alt-az mount. I'm happy to hear you are pleased with your upgrade. :elephdance: It sounds like a nice all-around performer.

#5 nirvanix

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Posted 09 April 2009 - 10:17 AM

Very nice review, thanks Ted. We are lucky these days to be able to get an 'entry level' scope of this quality for such a reasonable price. I recently bought an Orion 4 inch achro and I'm similarly impressed - the optics are great. I hope it gives you a lifetime of joy!

#6 chgomonitor

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Posted 10 April 2009 - 08:49 PM

All my thoughts exactly, as well. I've come to the conclusion I really made the right choice and that it's the perfect scope for me - at least while living near the big city. I adore doing the starhop thing with it and the alt-az mount really makes that easy. Thanks for the focuser tip, I'll try that. I can tell you I got a fat telescope catalog in the snail mail the other day and for the first time in my life I wasn't drooling over everything. Well, maybe a little...

Happy Sky Scanning! - Ted

#7 stevew

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Posted 11 April 2009 - 12:55 AM

Ted, Nice report, Congratulations on your fine telescope.

Steve

#8 m9x18

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Posted 11 April 2009 - 02:11 PM

Very impressive and in-depth report there Ted! I'm happy you're enjoying yourself with that nice scope of yours.

#9 Scott Beith

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Posted 11 April 2009 - 02:52 PM

Well done Sir. :)
Thanks for reviewing your scope for us.
I am looking forward to reading about more of your observations.

#10 Sky Captain

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Posted 11 April 2009 - 11:05 PM

Great in depth report Ted, very well done!
Congrats on the new equipment.






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