Takahashi FS-128 OTA & NJP Mount Review
By: Vlad Fedosov
Over the years I have had a secret crush on Takahashi(Tak) scopes. I have bought a few of the smaller models but my desire was always to own a 5” FS128! I’m not sure where this all originated from but the FS-128 was always one of the holy grail type of scopes for me. I have come close to picking one up on several occasions, but could never bring myself to pull the trigger on the beast because of the price tag… Well seeing how life is short and all, I got a chance to pick up an FS-128 on an NJP mount locally. After inspecting the scope and seeing that it was in absolutely mint shape, I jumped on the opportunity to finally own the scope that I had a crush on for such a long time! The FS-128 uses a 5” f/8.1 doublet objective with a Fluorite element. The tube weights about 16lb. Let's take a look at what this mid-size & arguably the sweet spot of refractors at 5” is all about.
I do evaluations of a lot of my reviews from my light polluted back yard. Seeing as how the Tak was a special scope to me, I did the initial evaluation of the scope from a special location. I was out for the weekend to the Jan Juan Islands that are at the very north-west portion of the United States. The sky the islands are in between a few US and Canadian cities so the sky is not completely dark but I could see down to magnitude 5-5.5 quite easily which is quite a bit better than from home! Having setup the scope on the NJP mount I just kind of took in how cool the scope looks in real life… In principle, a 5” refractor is a fairly large scope but now that I’m used to handling my Meade 178ED the Tak almost felt small. It's definitely a very manageable scope.
As the sun set, I was eager to get first light with the scope. I had a 31mm Nagler in the 2” MaxBright diagonal and pointed the scope at the first bright star I could see. Looking through the eyepiece I saw a magnificent little orb of light surrounded by a sea of dimmer stars. I honestly do not even know what star I was looking at but the view was spectacular none the less. It was very apparent that the contrast with the FS128 is excellent! As the evening went on and it got totally dark I swung the scope over to the double cluster in Perseus. This was a spectacular sight with the Tak as the contrast in the scope really made the clusters stand out. The color in the stars was very vivid and just a pleasure to see. For comparison, my Meade 178ED does show the colors in the stars a with a bit more vividness but from what I can remember the contrast is not as good. Overall the combination of the e31mm Nagler and FS-128 really felt like it was designed specifically to showcase this awesome pair of clusters!
The next pair of objects that I checked out with the FS-128 was M81 and M82. This famous pair of galaxies is a treat in any scope. This was certainly not an exception with the FS-128. The galaxies where easily framed with the 31mm Nagler. The view was not what I get out of my 18” dob as far as teasing out the finer spiral structure details but the overall shape of the galaxies was easily seen. Again the contrast was very good with an ink-black background. It was at this point that I decided to test the stability of the mount a bit. I would lightly hit the tripod with my palm and hardly see any vibration at the eyepiece. I later realized that at low power I can actually hold onto one of the legs of the tripod to steady myself with no evidence of vibrations. Simply amazing stability. I suppose this should not be too surprising as the mount is rated to carry 70lb. While on the subject of the mount I did find that the movements are very precise with the hand controller and there is very little backlash. I did find it weird that the motors kind of gradually ramp up to speed. This is definitely different compared to the constant speed that you can change on other mounts. I found myself overshooting the object a lot when trying to center it. This would of course not be an issue if using the mount with GOTO. I was just manually commanding the scope that night and I'm sure that I would get better at it with more use.
Swinging over to m45, again the cluster was very nicely framed with the 31mm Nagler. Contrast was great and I could just start to make out the nebulosity around the stars. This is where the Tak falls quite a bit behind my Meade 178ED. The 7” APO definitely displays much more nebulosity around the Seven Sisters. In fact, the 178ED has by far been the best view that I have seen of m45 ever in any scope. The extent of nebulosity in that scope starts to resemble what you are used to seeing from pictures of the cluster. The FS-128 shows some more nebulosity compared to my 4” Stellarvue SV4 APO but is quite a bit farther behind the 7” Meade APO.
It was a brutally cold that night on Orcas island so I called it an early night. A few days later we had a night of clear weather and I could not wait to try the Tak out at higher power! The planets were not around so I decided to do a little double star work. First I wanted to evaluate the color correction of the Tak. I pointed the scope as Capella with the 31mm Nagler and was greeted with the textbook perfect rendition of the star. Very nice! I then increased the magnification to around 86x with a 12mm Nagler T4. The star remained nice and tight but I could already see a bit of secondary color. Looks like the color correction of the bigger FS128 is about on par with its little brother the FS60 that I had earlier. As was noted in the FS60 review; while the color correction is not horrible with these scopes and they are a doublet design, I do feel that at the premium price point you should get a more color free image in 2019. In fact, my Meade 178ED has better color correction(by comparison my previous Meade 127ED had a little worst color correction). This particular Meade 178ED might be a bit better than the average sample though. Now I will make the normal disclaimer that my eyes are very sensitive to blue light. I know that a lot of people claim that Taks are visually color free. And for you, that may be true…
Next, I wanted to see what the big Tak can do on a few double stars. First up was Castor in Gemini. Castor is made up of a mag 1.58 and 2.97 component that is currently split at 5.2”(in reality this star is a system of 6 known stars!). With a relatively wide separation of 5.2” the Tak ate this double as an appetizer and wanted more! The stars were easily split and reminded me of a pair of car headlights. Next up was Delta Gemini. This is a double star in Gemini with a mag 3.54 / 8.18 components with a separation of 5.4”. Even though the separation is about the same as Castor the much greater difference in brightness makes this a much tougher double especially when the seeing is not great. Well, the Tak was also able to get a clean split on this interesting pair. The doubles were split with the 12mm Nagler T4. At this point, I did want to mention the focuser of the FS-128. It is a nice solid unit and is quite smooth. Critical focusing for double star work with it is certainly a pleasure but there is definitely some resistance focusing 'in' compared to focusing 'out' due to gravity with a heavy eyepiece. These days it is also quite substandard being a single speed unit. I do really enjoy the fact that you can rotate the focuser end though and wish that more scopes had this feature. Since the seeing was not that great this particular night I decided to call it a night for double star observing and decided to try out some electronically assisted astronomy(EAA).
I threaded on the dedicated f/6 Tak corrector that is made for this scope and mated it with my ASI 294MC Pro. I’m currently working through the Herschel 400 list from my mag 4 light polluted backyard with EAA. This night I decided to tackle the objects that are in Gemini since I was already in the area of the sky. Attached is a capture of NGC 2158, a dim open cluster that is right by m35. This is a raw “save as viewed” image from Sharpcap that has not had ANY post processing done at all besides resaving it in Photoshop as a jpeg so that it's not 15mb. This image also does not have darks or flat processing. Very pleases with the performance of the large Tak for EAA. As you can see with the larger sensor of the 294MC Pro some of the stars at the edges of the frame are a bit elongated but this might be due to the fact that I did not have the correct camera spacing. I’m honestly a real noob at this astrophotography type of realm, and for EAA these are more than acceptable results for me! I also did not see any secondary color in the images that the scope produced, witch is very nice.
A few weeks later I got a chance to take the big Tak to a small star party at Stub Stewart State Park. We had a group of about 6-7 people there on a cold late winter night. I setup the big Tak while the sun was going down. It was definitely an eye candy type of setup for a lot of us there. As it got a bit darker I took a look at the quarter moon. While centering it with the Tak 50mm finder I did note quite a bit of scattered light in the finder. Kind of not what I expect from a very premium finder. The optics on it are very sharp though. I first checked out the moon with my 40mm Explore Scientific(ES) 40° eyepiece. Very nice image! Since there was a thin layer of clouds at this point and it was far from total darkness I decided to try out the Denkmeier Binotron with the FS-128. Outfitting the binoviewer with a pair of d21 eyepieces, I put it into low power mode. Having a look, I nearly had my socks blown off! The view of the Moon was absolutely spectacular! The detail in the lunar features never seemed to end. The contrast, oh the contrast with this scope really is amazing and this was definitely the case on the moon as well. Even though it was not really great seeing and I was looking at it through some thin clouds(I think they where acting as a great moon filter) I can confidently way that this was the best view of the moon that I have ever seen!
As the night got dark we still had some patchy clouds around, but there where also some nice breaks in them. When I was Orion framed in a nice window of clouds I could not resist the temptation to take a look at m42 with the Binotron. As I was slewing the NJP mount around people could not help to comment on the peculiar sound of the motors. It kind of sounds high tech! It did not take long for my NJP to be known as R2-D2! Once I had m42 centered I was greeted with the familiar but very well defined Orion nebula. The nebulosity was well defined and the sky background was ink black. I loved the view. After a few folks took a look and all agreed that m42 was a very nice sight I proceeded to swap out the Binotron for an ES 5.5mm 100* eyepiece as we all got to wondering if the Tak can pull out all six members of the trapezium. Well even with the seeing being not so great most of us where able to glimpse all six members although they where definitely coming and going. The night wound down for me after checking out some more of my favorite DSO’s in the now totally clear sky.
I think that most of us would agree that the FS-128 and NJP is a premium telescope setup with world class performance. In the overall use of the scope, I can definitely confirm that it sure feels like it. This spans every aspect of the instrument from its sheer presence on the observing field to the smallest fit and finish detail on the scope. This setup does have a few minor drawbacks such as the single speed focuser, color correction that is not quite on par with a premium triplet. These are again minor things that are only worth pointing out because of the of the premium price of the scope. For me, from a visual perspective if I had to be restricted to only one instrument for the rest of my life this is one of only a handful of instruments that I would not hesitate even for a moment. This Takahashi setup really is impressive and a joy to use!