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Takahashi's Sky 90II

Posted by Trent Feist   07/22/2008 07:00AM

Let me start out by saying that this review is not going to be technical analysis of the Takahashi’s Sky 90II but solely my impressions of this Fluorite APO. I have owned many telescopes over the years and have never really been bothered by aperture fever. I have always preferred portability and ease of use over aperture and that is why I initially chose the Sky 90.

I sold my much loved Questar that I had owned for 10 years or so and decided that I wanted to move into a similarly sized refractor. The advantages of the Questar that I wanted to continue to have in my new scope was ease of portability, optical quality, overall quality of build, and a wide range of accessories. I was not interested in keeping the long focal length of the Questar as I already had a 5” SCT and felt that a faster refractor would be a nice complement. I read through many reviews of telescopes in the 90mm range and decided that I would go with the Takahashi Sky 90II.

The Sky 90II or FCL-90 as it is sometime referred to is an F/5.6 fluorite doublet with a focal length of 504mm. The overall length of the optical tube with the dew shield retracted is a short 16 inches and 18.5 inches when extended both measurements include the diagonal attached. Mated to the OTA is a 2.5 inch rack and pinion focuser that comes with both a 2 inch and 1.25 inch diagonal adapter. The overall weight comes in at 7.5 lbs. The size makes it easily fit into a carry on bag and easily fits under the seat or in the overhead compartment of a commercial aircraft.

As I am not an optical engineer I will not go into the makeup of the optical system or get to technical in my review, I will be sticking more to laymen’s terms. Upon arrival of the OTA I was instantly impressed with the build quality that goes into Takahashi instruments. The focuser was the first thing that I noticed. The locking feature that is built right in is a very nice addition and becomes very helpful during any sort of astrophotography or at public star parties where many hands are touching the scope. The focuser is incredibly smooth and solid and I noticed no backlash or image-shift at all. The Sky 90 came with a 6x30 finder and bracket as well as the standard clamshell to mount to my EM-10 Temma Jr mount. I put it all together and headed outside for first light. I turned first to the moon to see if any false color would be present. The only time I noticed any false color was if my focus was not spot on. Using the standard Takahashi focuser it was somewhat difficult to get the focus perfect. (I have since added the Feather Touch two speed focuser that has corrected the difficulty.) When the focus was spot on the false color vanished revealing excellent contrast across the surface of the moon and an inky black sky around the moon. I then turned to Saturn and easily spotted the Cassini division using my 11mm Nagler eyepiece. I could make out cloud banding on the sphere with some coloring. The image was incredibly sharp and contrast was excellent. I then turned to Jupiter and had a similar view with the scope revealing four moons, cloud banding and bits of color visible on the sphere. I didn’t notice false color on either planted unless my focus was off.

Having viewed the solar system objects it was off to the deep sky. I first turned to M42 and was rewarded with a stunning view. The trapezium was incredible and easily visible. Color was easily detectible throughout the nebula and the cloud bands were easily visible. I did not expect this from such a small aperture scope. M42 is one of my favorite objects and I was pleased to see so much detail coming from this little scope. I called my wife over to view and she was surprised as well as the Questar never gave the kind of detail we were seeing. (Then again the focal length of the two scopes is vastly different and the Takahashi has no center obstruction.) Having spent three or four hours at the eyepiece the first night I was very pleased with my new little scope.

I decided after the first night of viewing to order some accessories. I ordered the extender-q, the feather touch two speed focuser, camera angle adjuster and the field flattener. The stock focuser would be great for most people but given that I had purchased the scope with the plan of doing some photography I wanted the extra control provided by the feather touch. You may ask why I went with the Feather Touch over the Takahashi 10:1 focuser and that was simply my experience with Feather Touch products and their excellent reputation. The extender-q has been my second favorite accessory for this scope next to the focuser. The difference that it makes in lunar and planetary viewing is amazing. The false color issues I had experienced inside and outside of focus were gone with the extender-q attached and the longer focal length gave the planets even more detail and contrast. I highly recommend adding this accessory with the purchase of this scope.
Now, after almost two years of owning this scope I would strongly recommend it to anyone. I have had it out many times to our local clubs open house events and compared it to Televue scopes of similar size and it stands up well. I recently put the 8mm ethos to work in my Sky 90 and turned to M13 and was amazed to see pinpoint stars in M13 without using averted vision. This scope continues to provide stunning views. I don’t know if I would call my set-up a grab and go as the EM-10 mount weighs a lot but I do like the ability to simply carry out the OTA mounted on the mount and align with Polaris and get started.
What are the drawbacks? I have had a hard time finding any to speak of. One could say that the aperture limits viewing but you don’t spend $2000 on a 90mm OTA without realizing you are not going to see the details provided by a 10” Newt. The false color may be a drawback but one that is easily corrected with the addition of the Feather Touch and the extender-q. The only other disadvantage I can think of is the cost of Takahashi accessories but then again, if you are willing to part with the money upfront then the accessories shouldn’t be a problem

What are the advantages? The stunning view that is better than expected from a 3.5” scope. The size makes it easy to transport just about anywhere you want to take it. There are plenty of accessories to be had that make this already versatile scope one of the best all around scopes I have owned. Photography is easily done using the Takahashi accessories and the wide, flat fields provided using the field flattener is incredible.

Overall you can't go wrong with this scope. I don’t know why I don’t see more of them out there. There seem to be a number of 85mm Televues out there yet this little gem is often forgotten in the mix. If you are in the market for a top end refractor and haven’t been able to find a stowaway lying around then the Takahashi Sky 90II is the best thing out there. You will not be disappointed. The question you must ask yourself is about cost. $2000 will buy you much more aperture and possibly more accessories but it won’t buy you the stunning views and experience you will have with this little gem. I have found that having larger aperture usual means heavier and more difficult to setup and in the end less use. I have found myself spending more time under the skies with this scope than any other that I have owned. A final note; this past week I was able to setup next to a good friend that owns the local telescope shop. They have carried Televue and stocked Televue for as long as I can remember. After looking through my Sky 90II he said that he wanted to begin stocking it as he could see how people would opt for it over the 85mm Televue. In a world where gas prices have limited the ability to drive out to dark skies this little wonder performs perfectly right at home in my back yard.