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Review: Taurus T400 16" f/4.5 Ultra Light (without optics)
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Review: Taurus T400 16" f/4.5 Ultra Light (without optics)
The following is a summary of my experience from when I participated in an astronomy camp called astROmania, in Romania (Alba County).
It was there that I made my first astronomical observations with my new Taurus T400 telescope, the black version.
I’m writing my first impressions of this telescope, hoping to help those looking to invest in a Taurus truss Newtonian from Poland. The optics aren’t from Taurus, but they are excellent and were purchased separately, brought by a friend from America, to whom I’m very grateful.
I started being fascinated by deep-sky objects 13 years ago, after learning the constellations, and even then, I wanted to observe the sky with this type of telescope. The last four years of observations with the 200/1200 Dobsonian brought me closer to the Universe, but I was deeply impressed by the observations made through my colleagues' larger telescopes, where I managed to see some celestial objects in such detail. So, I eventually made this decision, even though it wasn’t easy.
When I received the telescope, I encountered some installation difficulties, mainly due to the mount base, which was undersized and more complicated than necessary. My colleagues at the camp helped me resolve this by moving the Teflon bearings and removing some parts, thus ensuring much smoother movements on azimuth. We expected a very good base and not so many issues, but we did everything we could to achieve the best movements possible.
Before mounting the primary mirror in the mirror box, we had to fix the support points and the mirror belt. When we tried to place the mirror into the mirror box, a problem arose: it didn’t fit into the main front opening of the box (we needed an extra 0.5 cm of space), so we had to dismantle everything and insert the mirror from the back of the box. It was unexpected, but we successfully resolved the situation, thanks, of course, to my experienced colleagues.
This telescope is very beautiful, with a fine, soft finish; the wood is painted in a very delicate matte black, so it requires more attention when handling it. However, even though this finish has a stunning aesthetic, in practice, it’s not so advantageous because it can scratch or chip quite easily in some places if you’re not careful when disassembling. Understandably, this is quite frustrating.
It has a huge advantage because it’s extremely light: without the mirrors, the whole system weighs only 16 kg, with the UTA, base, and truss bars being ridiculously light. Unfortunately, the same cannot be said for the box holding the primary mirror, the heart of the telescope, which is the heaviest component in the system.
I have many words of praise for the assembly/disassembly of the telescope, which was extremely easy for me; the UTA, truss bars, and altitude bearings have three large screws each, which always stay in place and never fall off, and they can be manually adjusted without tools.
First, you place the base on the ground, with the feet on three flat stones, then you screw the altitude bearings into the primary mirror box, after which you place the altitude bearings on their support on the base.
There are only 6 truss bars, and they cannot be separated, so they can only be opened together. After the screws are threaded into the primary box, the light shroud can be placed on the truss bars, and then the final step is connecting the three screws of the UTA to the truss bars.
It came with a light shroud that is very fine and light, with two small elastics that can be attached to two other screws in the primary mirror box for extra stability.
After this 10-minute installation process, collimation takes about 5 minutes and is done entirely by hand, without tools. To align the secondary mirror, I had to use a collimation laser and rotate two long screws on the back of the secondary mirror by hand. I managed to complete this step very quickly, in just 2-3 minutes, when the laser beam fell within the center circle of the primary mirror.
On the top of the primary mirror box, where the 3 holes for the truss screws are located, there are three more knobs, and two of them can be rotated to align the primary mirror, a step that is done just as quickly as for the secondary mirror. As you can see, the collimation system is very easy to access and adjust, with collimation being quick and simple.
I was pleasantly surprised to perform the star test and see that this telescope holds collimation throughout the night, as the defocused diffraction rings from bright stars had perfect concentric circles both at the beginning of the evening and at the end, in the morning. I saw this every night.
This whole process makes me optimistic about this truss telescope and incredibly happy with its simplicity, as it holds any target in the field without issues, as long as it’s not too close to the horizon, though it wouldn’t have hurt to have somewhat stiffer movements.
I forgot to mention the three transport bags: the altitude bearings and truss bars each have their own bag, while the UTA, primary mirror box, and base share the same large, bulky bag. It comes with a protective cover for the secondary mirror and a cap for the primary mirror box. The secondary heater has a sensor that automatically turns it on when needed.
Since installing the mirrors, I avoid keeping the primary mirror box, base, and UTA in their shared bag during transport. Although all three fit together in that bag, vibrations in the car could occur, so I don’t take the risk. I’m trying to find a more efficient protection solution, as the space in the bag is too limited to fit bubble wrap between the three components.
Now, the most important question is whether or not it’s worth investing in this telescope. Overlooking some disadvantages and focusing on the positive aspects, we can say that it’s worth it, considering that it’s an ergonomic truss telescope with several advantages, the most important being portability. Let’s not forget that access to the focuser is normal, without a ladder, which is perfect for my height and anyone who is 1.78 m tall.
Any object above 15 degrees from the horizon stays in the field of view without issue, and tracking objects is smooth, precise, and stable, so it’s effortless. However, I mentioned “disadvantages” earlier, mainly because of the base. It needs some improvements for the altitude bearings to have stiffer movements, so objects near the horizon can remain in the field of view.
I had to reposition objects near the horizon twice in the field before they stayed fixed in the center, but surprisingly, I didn’t encounter this issue consistently. However, upon closer analysis, the disadvantages of this truss mostly arise because many of its components are undersized, but this design works excellently for other smaller aperture Taurus truss models. So, the 16" aperture is the maximum structural limit for this design.
The undersizing of its components isn’t quite suitable for this 16" truss model because the image shakes quite a lot immediately after the target is placed in the eyepiece’s field of view. Only after 2-3 seconds does the image stabilize and stop shaking, but I didn’t encounter this with a homemade 14" truss, which had very rigid movements, so once the targets were in the field of view, the image didn’t shake at all.
It seems we’re dealing with a truss telescope that could have been made much better, considering its price. However, its advantages allow me to enjoy it immensely, as they meet exactly what I wanted from a telescope of this type: to be very practical, meaning portable and easy to manage, with good mechanics that facilitate maintaining collimation. I will use it every chance I get, grabbing it by the horns to enjoy the best views of the Universe.
I’m still thinking of a name, and “Taurus” seems quite fitting for now, as it’s black, has horns, and is very beautiful but also challenging, considering all the above.
- denis0007dl, robertasumendi, eyeoftexas and 3 others like this
17 Comments
Thank you for your review. I own a Taurus 300, the 12 inch model and did a review of it on Cloudynights last year.
My Taurus came with their optics, but not the upgraded optics option . I have been pleased with the optics and the Push - To which Taurus installed.
I do not do very much low altitude (ca. 15 deg) observing as we have a lot of trees. But I found that the use of the the two position mounting bracket would allow for better balancing, depending on the weight of eyepieces, etc.
Other reviewers have praised the optics , especially the upgraded optics.
I bought my T300 for travel, and it will just fit into a Pelican case and a duffle for the truss tubes. But a 10 inch model (not offered but Adam said he could design one), would be easier.
I like the light weight, and collimation which does not vary much even after transport of the two pieces inside our house from outside , or vice versa.
Again , thanks for the review. and I do think that the design of the mount is a little small for 16 inch scope, but perhaps with no shroud, wind would be not be a problem with shaking.
Yours,
John
Maybe installing the counterweight kit https://www.tauruste.../counterweight/
will help with heavy eyepieces/accessories and when viewing close to the horizon?
I have a 350, and it balances very well with PII and Ethoi.
I suspect your mirror might be lighter than the one supplied by Taurus. People who bought 400 with optics seldom complained.
Tracking is decent, true that it is not buttery smooth sometimes, but it is pleasant and you know where you are. Adjusting AZ friction is a matter of taste. Buttery tracking would require a completely different scope, one my back could not handle even now, let alone in the future.
I had in the past a very nice Taurus T300 with Orion UK mirror (very good). I was very pleased with that dobson, the only point which was a bit boring, was the size of the secondary cage. I now have a Dobson 16" (not Taurus) with a very lightweight secondary cage that I really prefer. The 3 vans on the spider are also a very good point in my opinion, it gives better contrast than 4 spider vans.
That looks cool. did you collimate it?
Good review, and nice telescope. Enjoy!
I started with weights but the quartz mirror is sooo much lighter than borosilicate glass that I needed 15lb or so. Instead I went with latex like so with some small trim weights https://www.cloudyni...223083-taurus2/
In all honesty, the robust secondary cage is a much more pleasant experience for me (stray light and also tracking). My Alkaid has a single UTA which is necessary compromise because it is an ultracompact, but Taurus secondary cage makes both focuser and the secondary less exposed.
I saw your post before I've placed the order and decided against going light. In theory, it could have worked, but tinkering with f ratio or mirror weight means that you one is getting away from the equilibrium reached by Adam. I was thinking about going to f/4.5 and in the end simply wanted to remove one more thing to worry about or have to somehow fix post production.
But, if I recall correctly - yours is a Zambuto mirror? If so, I reckon it is certainly worth tinkering with.
I don't see primary fans there - Taurus' solution adds some weight, ca 4lbs so not enough for your purposes.
Zambuto it is. I've always been partial to his work. I still use a trim weight but about 12 of the 15lbs equivalent that I needed is taken up with the latex. I foolishly hadn't really allowed for how imbalanced the quartz would be so had to improvise
I do not believe it is about weight of the material, but rather the thickness of the mirror. Mine is 34mm, I believe that is the thinnest it goes for the quartz mirrors of 20 inch size. If Taurus is made balanced for a much thicker mirror, that would bode ill for its cooling, as it is not about the diameter, but about thickness (and material).
My Alkaid has a 34 mm quartz mirror and cools really fast. I have not experienced any problems with Taurus pro mirror during sessions (I always leave the fans at a minimum during observation)
How old is your scope? I ask because the plate on the upper cage looks different, all the recent ones had data on diameter, focal length and a serial number (of sorts), with the first two digits referring to aperture...
Sorry if I don’t reply immediately!
This telescope doesn’t have any balance issues caused by the primary mirror — it’s very thick and heavy, definitely heavier than average. I always use it with a Paracorr Type 1 and an Ethos 13mm eyepiece.
The real issue was the base, which was poorly designed and undersized for this model. Because of that, I often had image shake after centering objects in the eyepiece.
The screw heads were placed over the large metal ring at the base where the Teflon pads sit, and the pads were hitting the screw tips while moving in azimuth, making the motion jerky. I had to relocate the Teflon pads in front of the metal ring, directly onto the wood, to get smoother azimuth movement.
That required removing several screws from the mount, but otherwise the motion would’ve been terrible.
Unfortunately, the altitude bearings are also undersized, and combined with the weak base, I had some annoying stability issues. I now place it on perfectly flat ground, and it behaves better, but if I move it quickly on both axes, the altitude bearings can jump out of the base slots — so I have to be careful not to move it too fast.
The telescope holds collimation all night long, which is great, but it’s a shame about the base. The design just isn’t suitable for a 16" — it feels more appropriate for a 12". I plan to build a new base in the future, and possibly new altitude bearings as well. I bought it last August, without optics from Taurus.
To be honest, right now I'm mostly focused on just getting it outside and observing as often as I can. The base works well enough now, as long as the ground is very flat and even.
Here’s my latest observing report, and from now on, I plan to always make reports like this.
https://www.cloudyni.../#entry14130396
Hm, I am not sure I understand.
The screw heads you talk about in azimuth are adjustable friction knobs. CW and less tension, CCW and more tension (counterintuitive, I admit). That way, you adjust friction in AZ to your liking.
Altitude bearings are certainly not undersized at 350. Can't vouch for 400. Alt is stickier than Az (once Az is dialed via those teflon adjustments).
My Az movement is really smooth. In fact, I overshot and made it too easy the first time around.
Well, I don’t know how it is for you, but I’m glad if the base works fine on your end. In my case, the screw heads used to fix the large metal ring to the wooden ring of the base were completely inappropriate. When I say "ring," I’m referring to the circular part parallel to the ground — not the altitude bearings or the Teflon tracks where they move.
On that metal ring, only the white Teflon pads were supposed to slide freely, without any obstacles. Unfortunately, they kept hitting the screw heads, which made the azimuth motion jerky and abrupt — completely unacceptable. We tried every possible fix, but nothing worked, so I had to remove some parts and reposition the Teflon pads in front of the metal ring, directly onto the wood. Now the base moves much better, but this issue shocked everyone in our observing camp.
Taurus could have built a sturdier and simpler base. At this price point, I didn’t expect such a problem. I'm disappointed, especially since I’ll probably have to rebuild the entire base — maybe even the altitude bearings as well. Other than that, the telescope works fine, except for the finish, which scratches very easily.
I found this picture
https://stargazerslo...Comment-4207409
bottom of the post - are you talking about screws securing azimuth bearing ring? They look completely not in the way of the Teflon pads.
I will have to check - but I cannot as my scope is in my trunk of the car, waiting for the New Moon.
Hi,
I don't quite understand :
"I’m trying to find a more efficient protection solution, as the space in the bag is too limited to fit bubble wrap between the three components."
Why would you want to place bubble wrap between the components? Did you notice that the primary mirror box screws onto the primary mirror box?
What's more, I own a Taurus and haven't encountered any of the problems you mention. On the contrary, this telescope is very well designed and gives me complete satisfaction from every point of view, both mechanical and optical ("pro" mirrors).
For example, it is possible to modify the centre of gravity by fixing the altitude bearings at different heights on the base.
The collimation is very stable and lasts all night, etc etc....