Swarovski ATX 115 in the field: a comprehensive test of the most powerful ground-based telescope, up to 120X.

PREMISE

Those who have been following me since 2006 on Binomania.it, and even before that since the mid-nineties on astronomy magazines, will remember that I have often had the pleasure of observing with large-diameter telescopes. As for the so-called telescopes for naturalistic observation – the spotting scope – the largest diameters I had tested in the field were between 95 and 100 mm.

I had not yet had the pleasure of using it in the field Swarovski ATX 115, which currently represents the largest compact and modular instrument for nature observation available on the market.

Those who follow the YouTube channel will have noticed that, a few days ago, I went to the Domodossola shop Marco Lucchini to collect two ATX modules for viewing: the 65 mm and the 115 mm.

I am pleased to begin by presenting my opinions on the naturalistic use of the technique in photographic sessions. digiscoping, and also in astronomical observation.

Enjoy watching and reading!

 

 

AVAILABLE FORMATS

The system ATX It is a modular system and is equipped, first of all, with three ocular modules: ATX, STX e BTX.
The model ATX it is the angular system, the model STX it's the straight one, while the BTX it's the form binocular.

In addition to this, there are well available four lens modules with diameters of 65 mm, 85 mm, 95 mm e 115 mm.

Prices start from 1,010 euros for the smallest diameter, up to the 3,140 euros for the gigantic 115 mm.
Doing two calculations: adding to the 3,140 euros of the 115mm lens module the cost of the eyepiece module from 2,530 euros, it is understood that it is possible to purchase the complete system with the larger module for a price equal to 5,670 euros.

 

ACCESSORIES SUPPLIED

I invite you to visit the report just mentioned to check the accessories available in the package.

The system is supplied complete, with:

• Eyepiece module (ATX/STX/BTX, depending on the version chosen)

• 115mm lens module

• Front and rear lens covers (glare caps, front shields)

• Tripod collar with bayonet– allows the assembly of eyepiece and objective, ensuring waterproofness and ease of transport

 

OPTIONAL ACCESSORIES

The There are countless optional accessories that can be purchased. Starting from CA-S, a clamp adapter that attaches to the VPA 2, the smartphone adapter. You can also use a external field casing.

As for the digiscoping, as I will explain in a specific paragraph, you can benefit from the system TLS APO. Furthermore, you can choose between the CCT series carbon tripods, the head CTH, The adapter rings, The ME multiplier 1.7x, and the professional tripod head PTH.

TLS APO System for Digiscoping

Compared to other companies in the sector, which leave the customer the choice of using their own photographic lenses for the digiscoping technique, Swarovski Optik has provided a dedicated system: the TLS APO, equipped with apochromatic lenses, developed to allow you to fully exploit the telescope's field of view and also optimize the geometric and chromatic aberrations.

It is available in three formats:

• 23 mm for cameras Micro Four Thirds (Micro 4/3)

• 30 mm for cameras APS-C / DX

• 43 mm for cameras Full Frame

As you will have understood, in this case too you benefit from an excellent modularity of the system.

The first component I received for viewing from Marco was the 23mm TLS APO, as I also use a system OM-1 digital (formerly Olympus), which I find very suitable for nature shots. It is an extremely mirrorless waterproofed, equipped with excellent stabilization on the sensor (5 axes and 8 EV stops) and, being also quite compact, reduces vibrations of your digiscoping kit.

To this we must add the purchase of the’T2 adapter ring for Micro Four Thirds. The total price of the TLS APO starts at around 700 euros.

The system features a excellent quick release/attachment mechanism: as you can see in the video review, you just need to unscrew the eyepiece, fit the component, screw it in. lowered lens hood, supplied with the TLS APO system, then allows – once the T2 ring and the TLS APO have been connected to your reflex or mirrorless camera – to quickly switch from pure observation to video or photographic shooting without vignetting.

 

ME 1.7x – Teleconverter

Marco Lucchini also lent me the ME 1.7x teleconverter, which you can use both with the four objective modules, both with the ATX, STX and BTX eyepiece modules.

Different magnifications will be obtained in proportion to the focal length of the lens.
With the form BTX 115, for example, the minimum magnification is equal to 60x, while the maximum reaches well 120x.

You will therefore understand that, with such a system, in addition to observing terrestrial details at very long distances, you will also be able to perceive the weaker and fainter details of raptors and avifauna generally, at distances impossible to reach with smaller diameter telescopes not equipped with a focal multiplication system.

Furthermore, such enlargements already allow us to observe very interesting details of the planets and of the morphological reliefs of the Moon.

I will explain my impressions further in the section dedicated to’practical observation.The cost of the ME 1.7x is of 508 euros.

MECHANICS AND FOCUSING SYSTEM

 From a construction point of view, the first thing that catches the eye is the ATX system modularity.
This telescope, while obviously quite large and heavy when mounted, can be divided into two main components to be carried comfortably inside a backpack.
This is a factor that is not secondary and not common to all other competing naturalistic telescopes.

That said, the telescope is made up of a magnesium hull, obviously robust and well waterproofed, capable of withstanding operating temperatures ranging from -25°C and +55°C, and able to bear an immersion in water up to four meters deep.

Swarovski declares a weight of 2,100 grams for the 115mm optical module, to which must be added 810 grams of the eyepiece module.

Personally, I preferred to weigh it with all accessories mounted which I used in my practical field test: so with plate for the Cartoni FOCUS 10 video head e main component of the TLS APO attached to the optical hull, including the specific lens hood supplied with the TLS APO.
My electronic scale estimated a total weight of 3,196 grams.
We can therefore say that we need to consider approximately 3 kg of weight for the classic equipment in observation and digiscoping configuration.

The Swarovski ATX 115 is protected by a excellent coating similar to that used in the high-end binoculars of the Austrian brand: it is characterised by a Swarovski green coloring, combined with details blacks, and from a porous surface texture which makes it much easier grip, even with sweaty hands or with winter or shooting gloves.

On the front of the eyepiece module is the historic silver plaque with the Swarovski logo, which represents a distinctive feature of the Austrian company.

The lens hood is removable, while on the right side of the eyepiece module there is a quick release button, which allows the removal of the eyepiece module from the optical module via a excellent bayonet system, which maintains waterproofing even after the separation.

On the optical module, immediately after the helical focus, is present a swivel collar which allows a full 360° rotation, useful for adapting the instrument to any observation or shooting configuration.

A peculiarities of the ATX system is that the eyepiece module integrates the magnification variation system, which in this case is between 30x and 70x.
The adjustment ring is knurled, has a large section (approximately 30 mm by 76 mm) and it turns out easily maneuverable even with winter gloves, a very appreciable feature in observations in the mountains or during the winter.

As for the focusing system, Swarovski has adopted a helical mechanism similar to that of photographic telephoto lenses. The ring measures approximately 69 mm x 52 mm and it is also equipped with a knurled rubber cover, which facilitates grip even in difficult weather conditions.

At the minimum magnification range, i.e. 30x, I estimated a minimum focusing distance of approximately 4 meters.
To reach infinity it was necessary to rotate the knob clockwise about two and a half turns. This is undoubtedly a superior performance compared to what can be achieved with the classic small focus knobs present on some competing products. The system has proven to be fluid, mechanically flawless, free of games or stumbling blocks.
Also noteworthy is the snap test: the focus point is clear and unambiguous, without any uncertainty, allowing precise and immediate adjustment even on the smallest or most distant subjects.

Another notable performance concerns the use of the ME multiplier 1.7x: in this case, I was able to focus on a subject just 5.8 meters away, to then reach infinity always with approximately two and a half laps of the knob.
Such an excursion, so fluid and wide, is impossible to obtain with a classic astronomical telescope, which is not usually designed for such close and progressive focusing.

OPTICS

Objective

As far as the objective is concerned, we are faced with a true record in the field of Earth observation telescopes: a diameter that I would define as "astronomical"“, not only in size, but also in terms of optical performance which offers, especially in terms of brightness e perception of details, proportional to the magnification usable with this system.

This is a tool that can be compared in performance to a very good apochromatic refractor of at least four inches. I am not given to know the exact optical formulation used by Swarovski, but I can confirm with certainty that it is a apochromatic project, well corrected from a chromatic point of view - The colours are faithful and bright, the tone of the whites is neutral, the sharpness is very high, as well as the contrast, And no decay is observed of these characteristics not even to extreme enlargements.
Indeed, the only limitation encountered while using it with the multiplier 1.7x è  due exclusively to atmospheric turbulence, not to the instrument itself. Interestingly, the lens is equipped with front thread with step M118x0.75, which allows you to possibly apply a protective filter: a rare feature, but very useful in certain operational contexts.

Eye

The eyepiece benefits from a generously sized field lens, equal to almost 29 mm.
THE'’pupil extraction declared by Swarovski is of 20 mm: a value also confirmed by my practical experience. In fact, I have had no problems using it. even at the shooting range, wearing shooting glasses. 

The exit pupil diameter varies from 3.9 mm to 1.6 mm, depending on the selected magnification, while the linear field of view declared is between 35 and 19 meters at 1000 meters, equivalent to 1.98° – 1.09°.
Translated into apparent field, you get an amplitude that varies between 57th and 71st, definitely values broad and engaging, especially for a variable magnification system. The dioptric compensation expected is ±5 diopters, a very good value that allows perfect customization even for those with significant visual corrections.

ANTI-REFLECTION TREATMENTS

Swarovski has adopted high-quality anti-reflective treatments on all optical surfaces of the ATX spotting scope.

Currently, Austrian optical technology is based on four proprietary coatings, each with a well-defined purpose:

• SWAROTOP® – Multilayer coating that optimizes light transmission e minimizes internal reflections, improving the overall brightness and contrast of the image.

• SWAROBRIGHT® – Specific treatment for maintain a neutral color rendering e a high contrast, particularly useful for fine detail distinction in critical lighting conditions.

• SWARODUR® – External coating hard and resistant, applied on the exposed optical elements, which guarantees a effective protection against scratches and abrasions during field use.

• SWAROCLEAN® – Coating water-repellent and oil-repellent which facilitates the Cleaning the front lens and field lens of the eyepiece, reducing the adhesion of dust, water and fingerprints.

This combination of treatments gives the instrument exceptional optical quality and ease of use, maintaining high performance even after years of use in difficult conditions.

PRISMS

The eyepiece module employs a very high quality prism of the type Smith–Pechan, an optical configuration that allows to obtain sharp, bright, high-resolution images, while maintaining compact size.

This type of prism, thanks to its complex optical structure, is also able to minimize vignetting, ensuring a well-used field of view across the entire extension. During use in the field, I carefully analyzed the exit pupil: it turned out perfectly circular, free from irregularities or lateral glare, an unmistakable sign of excellent interior design and finishing.

This aspect is fundamental for prolonged use, especially in backlit situations or with low contrast subjects, and confirms the’optical excellence of the Swarovski ATX 115, worthy of the best naturalistic and astronomical observation instruments available today.

USAF CHART TEST AT 35 METERS

At 30x, with the USAF chart positioned at 35 meters, I was able to clearly distinguish the vertical and horizontal lines corresponding to the number 4. At 70x, I was able to perceive the same lines, but located on the opposite side of the chart. Chromatic aberration is decidedly well contained: it becomes visible only by moving from the center towards the 30-40% of the field, where a faint green-purple fringing begins to appear on the thicker lines. Finally, I performed an extreme test at 120x, managing to perceive the number 6 even at noon.

 

CHROMATIC ABERRATIONS

Chromatic aberration at the center of the field

THE'’chromatic aberration at the center of the field is well corrected. This telescope has successfully passed my now usual and selective “white gazebo test”, not only at the maximum magnification of 70x, but also to 120x using the 1.7x ME multiplier.

I stayed pleasantly surprised, considering that at such magnifications the image of the white sphere occupied almost the entire field of view. performance of this level I was able to appreciate it only with high-quality apochromatic astronomical refractors, which once again confirms the exceptional optical correction of the ATX 115 despite its very open focal ratio.

Lateral chromatism

There lateral chromatic it is present, but to a lesser extent non-invasive. It manifests itself by progressively moving from the center towards the edge of the visual field, becoming noticeable starting from around 50% of the field itself. This aberration manifests itself mainly on high-contrast subjects, in the form of light green or purple fringes at the edges of the shapes. In practical use - for example when observing from a shed or taking panoramic shots on the slopes of a mountain - it is hard to notice, and in general does not compromise the viewing experience.

GEOMETRIC ABERRATIONS

Field curvature

The telescope features a virtually flat field of vision: a feature very rare in a spotting scope and absolutely exceptional.

Observing at the various permitted magnifications, from 30x to 70x (or even more with the multiplier), is a real pleasure: the details remain sharp and defined across the entire field of vision, from the edges to the center. Even in the astronomical field, the stars remain almost perfectly point-like up to the very edge. The sharpness at the edge is almost identical to the center; only a minimal correction of the helical ring is needed, but our eyesight often compensates admirably. This is, in all likelihood, one of the best performances that I have encountered in terms of field curvature correction in a ground-based telescope.

Angular distortion

There is a slight pincushion distortion, intentional: an optical compromise adopted by designers to improve ease and naturalness of use in panning.

Other aberrations in astronomical use

During astronomical observations, I did not detect any noteworthy aberrations in addition to those already listed. I will not use my classic table with CM-CU and CI (maximum contrast range, still usable range and insufficient range) because the performance towards the extreme edge is almost identical to that in the center, so much so that I would call it CM 100%.

 

 

PHOTOGRAPHY AND DIGISCOPING

As for photography with this observation system, Marco Lucchini kindly let me test the module TLS 23mm apo, which allowed me to take advantage of the shooting in 4K of my OM-1. In addition to some photo sessions I also tried to use my iPhone XR with a specific adapter for the Swarovski eyepiece and I can confirm that, for my way of using this instrument, the technique with the smartphone has proven to be much more practical than the TLS apo, which I find more cumbersome.

However, I must be honest in acknowledging that filming with the mirrorless, Both Micro Four Thirds and full-frame cameras offer significantly superior performance. This is because, although they are heavier to carry, mirrorless cameras have sensors much larger than those in the iPhone XR, ensuring superior dynamic range, sharpness, and resolving power.

I haven't had the opportunity to test the TLS APO with a full-frame mirrorless camera, but I'm sure that, especially at twilight, performance would improve further. The OM-1 Digital is particularly suitable for this type of nature shooting, thanks to its excellent waterproofing, robustness, and above all the on-sensor stabilization which can reach up to 8 stops. For this reason, I really enjoyed photographing birds and other animals during the twilight hours. You'll find many examples in the video: from roe deer at dusk to egrets and extreme landscape details.

 Compared to other solutions on the market, I really appreciated that Swarovski designers developed a specific lens for this activity.. In fact, the results often vary greatly depending on the photographic lens used, while in this case you can be sure that the system was created specifically to maximize performance with mirrorless cameras.

If anyone is skeptical about the large aperture of the Model 115 for ground-based observations

at medium magnification — as I had already underlined in a dedicated video, where atmospheric turbulence tends to level out performance—in the case of twilight shots, the ATX 115 proved truly impressive. I captured videos of deer between 9:30 and 9:50 PM that I would never have been able to capture with a classic “85mm.”.

I admit that I didn't ask Marco Lucchini for the TLS apo system for my full-frame Canon, which would probably have further improved performance.

As for naturalistic birding, a large diameter like the 115 mm is obviously limited by atmospheric turbulence: July is not the best month to fully exploit the potential of this terrestrial telescope. However, I did my best to capture subjects between 20 and 100 meters, getting up early in the morning to visit the well-known hotspot of Germignaga. In the video review, I show you some shots of egrets and herons between 50 and 120 meters, obtained in excellent light, according to Ma, but with a lot of wind.

They were taken between 6:30 and 7:30 in the morning. In ideal weather conditions for transparency, less so for wind, I believe the TLS apo system combined with the large diameter of the 115mm f/2.8 can offer exceptional performance at high magnifications and over long distances, provided you can somehow shelter yourself from gusts of wind. I was thinking, for example, of shooting inside photo hides or with the tripod completely lowered, a mode I personally couldn't set up in those conditions. In any case, the videos, based on my experience, are truly promising.

I also remind you that the focal length depends on both the sensor and the TLS apo module: for the 115mm module, Swarovski declares a variable focal length between 900 mm and 2100 mm, which can be further amplified with the 1.7x multiplier, bringing it to 3570 mm. If you then also use the Olympus digital teleconverter, you can reach focal lengths equivalent to over 7000 mm — a result that until a few years ago seemed like science fiction.

 

FIELD TEST

Birdwatching

More than a birdwatcher, I consider myself a bird of prey enthusiast.. I love observing these majestic birds so much that often, even during my shooting sessions in the mountains, I stop to grab my binoculars and spotting scope and dedicate myself to observing the short-toed eagles and golden eagles that populate the area under the astonished gaze of the other shooters.

For this reason, I focused my attention on observing buzzards, short-toed eagles, and, fortunately, even a few golden eagles. I must confirm that the daytime performance of the Swarovski ATX 115 is phenomenal: compared to the 95 mm model, much clearer details are visible, especially in shadowed areas. For example, when observing a young specimen, the underwing showed very clear colors and details, with a truly enviable ease and comfort of use of the exit pupil.

As I've repeatedly emphasized, daytime turbulence can dampen performance, especially during the hottest hours of the day, when birds of prey exploit thermals. In these situations, I preferred to observe at lower magnifications, around 30-40x, because the large diameter of the 115 mm amplifies turbulence. For this very reason, I used a wooden diaphragm (approx. 75 mm) crafted by a craftsman at Marco Lucchini's request, to great effect. The difference was also evident at the shooting range and during the daytime test with the USAF CHART: the perception of turbulence was significantly reduced.

I would recommend that the Austrian company provide a pair of apertures to be used at least with the 95 and 115 mm models, because they can significantly improve the perception of micro details during the hottest hours.

This is not just my opinion, but a well-known fact: the larger the diameter, the greater the amplification of turbulence. This feature is perhaps better known to amateur astronomers than to birdwatchers, but having used such a large diameter for nature observation I have understood how useful it is to adopt a diaphragm, especially in the month of July between 10 and 15.

The Swarovski ATX 115's capabilities were incredible at first light: at 6 a.m., I captured an extraordinary image of some herons on the shores of Lake Maggiore, near the mouth of the Tresa River. At 120x magnification, I could observe dozens of details, from their beaks to their plumage. I was so amazed by the sharpness and contrast that I often had to check the magnification on the dial, because it seemed like I was observing at much lower settings.

 

Landscape observation

For those who are demanding and looking for a modular system that is easily transportable, but capable of offering very high magnifications, the Swarovski ATX 115 undoubtedly represents the definitive instrument.. The field of view is perfectly flat all the way to the edge, ensuring a sharp, distortion-free wide-angle image from the center to the edges. Color rendition is neutral and faithful: the 115 mm allows you to perceive true colors even at dusk and dawn, especially at low magnifications, while instruments with smaller diameters tend to display more grayish tones.

I was amazed to observe incredible detail. At 120x magnification, inside a cabin located 32 kilometers away, I was able to make out the silhouettes of several people moving their heads behind the cabin's illuminated windows—details usually reserved for astronomical observations or in contexts of maximum visibility.

When I'm waiting for nightfall on Mount Sette Termini, I often enjoy sweeping the landscape for miles around, observing the shores and outlines of the Piedmont mountains. For those who prefer a lighter system, suitable for trekking, I highly recommend the 65 mm module, which we'll discuss in more detail in a future article.

Twilight observation

I've often been a bit skeptical about the twilight performance of many binoculars and spotting scopes, considering them to be "lukewarmly" decent, especially because these observations require very bright optics or specific instruments for very low light conditions. In this context, the Swarovski ATX 115 at 30x magnification proved to be very high-performing.

I was able to observe with great pleasure Roe Deer, Foxes and Hares in twilight conditions, when instruments with smaller diameters struggled to show significant details, especially against dark undergrowth. The ATX 115 with its 3.8 mm exit pupil at 30x has proven to be, in my opinion, the best terrestrial telescope currently available on the market for twilight observation.

Astronomical observation

With a budget of around 6,000 euros (including the 1.7x multiplier), it is understandable that you can purchase an astronomical telescope with a very large diameter specifically for astronomical observation and photography. However, the lucky owner of the Swarovski ATX 115 will also benefit from excellent performance for deep-sky observation, thanks to a diameter of almost 5 inches, and excellent observations of the lunar surface, especially using the 1.7x multiplier, which allows for up to 120x magnification.

I remind enthusiasts that a telescope displays all the detail its resolving power allows at a magnification of about two-thirds of its diameter expressed in millimeters. Therefore, a 115 mm telescope used at 120x certainly displays all the possible details, with a few dozen more magnifications useful for less experienced observers to perceive the faintest details.

In my late-night observations, I was able to observe the planet Saturn with a level of detail similar to that of an excellent 4-inch refractor. On the Moon, dozens of micro details can be discerned: from lunar rims to humps, to minimal craters, and more.

Compared to daytime, atmospheric turbulence at night is present but less invasive, almost always allowing the 1.7x multiplier to be used to its full potential for high-resolution observations. The large diameter of the ATX 115 is especially appreciated at low and medium magnifications, such as when observing star clusters, where the edge-of-field performance is perfect: stars remain pinpoint-sharp all the way to the edge, making it a pleasure to frame objects like the galaxy M81 and the nearby M82 in the constellation Ursa Major. At around 70x magnification, the characteristic shapes of galaxies can be observed in great detail. The same experience is repeated with star clusters, such as M13, which I have observed several times with great satisfaction, so much so that I doubted whether I was looking at a terrestrial instrument and not a specialized astronomical refractor.

If I have to mention only one limitation — besides the price and the specific use of this instrument — it is the inconvenience of observing at the zenith, given that the 45° viewing angle is less comfortable than a traditional astronomical telescope with a 90° diagonal, but we all know that this instrument was designed to excel in astronomical observation.

Strengths and weaknesses

Merits

• Modular system of high optical quality

• Excellent containment of chromatic aberration

• Flat field

• Possibility to purchase eyepiece and optical modules separately, according to your needs

• Wide and usable magnification range

• Fully usable 1.7x multiplier, weather-compatibly

• Excellent digiscoping system

• Ease of transport thanks to the separation of the components

Defects

• Heavier than a classic 82mm spotting scope

• In the presence of strong temperature variations and daytime turbulence it is preferable to stop down the ATX 115 to limit the effects of turbulence. In such conditions it would be preferable to observe at lower magnifications, around 20-23x.

• The 30x does not allow for high fields of view like terrestrial telescopes which can have wide fields of view at 20x-25x.  

In summary

I believe that Swarovski has achieved several firsts with the ATX series, and in particular with the 115 optical module. It is, in fact, the largest terrestrial telescope in the world, given that the competition currently limits itself to diameters between 95 and 99 mm. It also offers a modular system that allows for the purchase of more compact optical modules over time, thus providing completely different instruments. A digiscoping system with a dedicated TLS apo lens has also been developed, which performs extremely well with the latest-generation mirrorless and DSLR cameras.

If you are passionate about long-distance nature observation, you love studying landscape details, birds of prey and other animals, and you have to do it even in difficult weather conditions, I think there is nothing better on the market than the ATX 115. This instrument offers a truly usable magnification range of 30 to 120x, making it extremely versatile, considering the use of a diaphragm for daytime observations in the central hours of the day during summer.

Price and guarantee

The Swarovski ATX 115 currently has an official list price of €5,670. The 1.7x multiplier costs €508, while the TLS apo starts at around €670.
I recommend visiting Marco Lucchini's shop in Domodossola, which offers a wide selection of optical modules, eyepieces, and accessories for the Swarovski ATX system and will surely satisfy every need.

Acknowledgements

As always, I thank Marco Lucchini for providing the specimens and accessories for this test, allowing me to express my personal and practical impressions in the field.