Headquartered within the sun-drenched Mediterranean coastal metropolis of Marseille in southern France, Unistellar manufactures technologically superior telescopes that eschew typical optical designs in favour of a hybrid opto-electronic strategy: one ‘sees’ what the eVscope is taking a look at, both by a high-quality miniature OLED (natural LED) display screen masquerading as an eyepiece on the aspect of the instrument, or on the display screen of a Wi-Fi related smartphone or pill that doubles because the eVscope’s hand controller.
Moreover, every ‘Enhanced Imaginative and prescient’ eVscope is totally selfcontained and eminently moveable (a custom-made backpack is an optionally available further), possessing a built-in image-processing pc and a self-aligning monitoring mount plus tripod, all powered by an inner rechargeable battery that may function the instrument for a complete night time of observations. Regardless of a symphony of technological wizardry required to make all of it work, Unistellar’s intelligent software program ensures that an eVscope is each highly effective and extremely simple to make use of – which is a neat trick to drag off.
Every eVscope person can be invited to change into a part of a thriving on-line neighborhood of ‘citizen scientists’ inspired to take part in wide-ranging observations of asteroid occultations, exoplanet transits, near-Earth asteroids, cometary exercise and extra. One might say that the eVscope exists to make science enjoyable, designed from the bottom as much as attraction to those that one minute want to seize pictures of deep-sky objects after which share them over social media, and the following minute to be gathering information in observing programmes that profit skilled astronomers.
The unique eVscope’s public debut occurred on the Las Vegas Client Electronics Present in 2017. Though the introductory mannequin has since been discontinued, Unistellar at present has two different fashions in manufacturing: the ‘finances’ eQuinox and the eVscope 2. Since all eVscopes function in a really comparable style and use the very same management software program, this appraisal focuses on the eVscope 2’s new {hardware} and options. For an in depth have a look at the operation and efficiency of former Unistellar fashions, see my opinions within the August 2020 and September 2021 problems with Astronomy Now (you can even discover them on-line at astronomynow.com).
New options
Unistellar’s newest product seems equivalent to the eVscope 1 at first look, even right down to the silver tube and charcoal gray livery of its predecessor. It doesn’t even have an ‘eVscope 2’ label on the aspect! The eVscope 2 additionally options the identical 11-centimetre diameter, 45-centimetre focal size (f/4) parabolic mirror of former fashions, so don’t anticipate an instrument of bigger aperture or alternate focal size.
There are, nevertheless, two important variations to the eVscope 2. First is a brand new, bigger digital sensor that lies on the instrument’s focus: a Sony IMX347LQR CMOS chip with an efficient array of two,712 × 1,538 pixels, every 2.9 microns (0.0029mm) in measurement. Evaluate this with the Sony IMX224 sensor utilized by each the eVscope 1 and eQuinox, and which possesses a matrix of 1,304 × 976 pixels, every 3.75 microns (0.00375mm) in measurement.
Therefore the eVscope 2’s sensor measures a fraction greater than 9mm throughout the diagonal in comparison with to the 6.1mm diagonal of the opposite Unistellar fashions. Given the equivalent focal-length optics of all of the devices throughout the vary, because of this the eVscope 2’s most area of view exceeds that of its predecessors by 47 per cent – no less than in principle. Moreover, the smaller pixels of the IMX347 sensor implies that the eVscope 2 has a finer decision of roughly 1.3 arcseconds in comparison with the 1.7 arcseconds of former and present fashions. I’ll return to precise measurements of the instrument’s area of view and determination later.
The second important distinction between the eVscope 2 and its predecessor is the brand new and improved eyepiece on the aspect of the instrument developed in partnership with Nikon. As with the eVscope 1, the digital eyepiece is actually a loupe with a premium high quality miniature OLED display screen at its focus. Nevertheless, the optics of the eVscope 2’s eyepiece are multi-coated and an improved design to that provided with the debut mannequin.
First impressions
Like its predecessors, the eVscope 2 and its computerised alt-azimuth mount is an integral unit with a separate three-section tripod; the latter is exclusive and customary to all Unistellar fashions – you possibly can’t use an alternate tripod. You additionally obtain a field of equipment containing a charger with interchangeable journey plugs, a toolkit, plus each fast begin and technical guides. In the event you purchased the optionally available backpack, the instrument is delivered inside it.
The eVscope 2 features a detachable cylindrical foam wedge inserted between the bottom of the optical tube and the mount throughout transportation. With none carrying handles, one’s inclined to know the entrance of the instrument when eradicating it from the backpack or the close-fitting foam of its field – aleverage that locations nice pressure on the clutch-less altitude-axis gearing, until there’s something to assist it. Maybe Unistellar obtained too many returns of former fashions with overstrained altitude drives.
Meeting and set-up is simplicity itself: open, prolong and clamp the legs of the photo-style tripod to the required peak, degree the tripod head utilizing its built-in bubble, then slide the mount into place and safe it by two thumbwheels. You obtain two spare thumbwheels do you have to lose any whereas away from residence, which is a pleasant contact, however maybe they need to be captive. The eVscope 2 has a mass of 9 kilograms totally assembled, so you possibly can simply choose it up and transfer it round to entry a greater view of the sky.
You want a latest Android or Apple smartphone or pill operating the free downloadable Unstellar app to function the instrument. In widespread with former eVscope fashions, the one bodily management on the mount is a lozenge-shaped energy button within the fork arm. On the underside of the fork is the place you discover a USB-C port for charging the interior battery. There’s additionally a USB-A port that you need to use to recharge your smartphone or pill.
The Unistellar app
Each eVscope generates a singular, password-less Wi-Fi hotspot for wi-fi communication between your smartphone/pill and the Unistellar app. Whilst you can function the eVscope 2 from a distance of some metres, for reliability and responsiveness you’ll get a greater expertise standing shut by. On the time of writing, the present model of the Unistellar app is v1.6 for iOS and Android. The app additionally routinely updates the telescope’s on board pc firmware, if required. I used the app on an iPhone 6S+ (iOS 15.5) and an Android 7 smartphone – each thought-about reasonably previous tech – with none points.
The Unistellar app’s residence display screen opens with the Reside-View stream from the related eVscope, initially setting computerized limits on acquire (suppose ISO setting on a digital digital camera) and publicity time (from one millisecond to 4 seconds). Nevertheless, the app has a guide mode the place you possibly can manipulate acquire and publicity sliders whereas observing the Moon, a vibrant planet, or a double star, to boost the view considerably if it’s under- or over-exposed.
As you’d anticipate, the Unistellar v1.6 app incorporates the easy-to-use Autonomous Discipline Detection (AFD) alignment and monitoring system of former eVscope fashions, in addition to the showcase Enhanced Imaginative and prescient (EV) gentle accumulation function for miraculously enhancing the views of deep-sky objects in mere minutes. Each processes are actuated by single button presses on the app’s residence display screen.
The eVscope 2’s view of the sky is mirrored to the digital eyepiece in addition to within the Unistellar apps of as much as ten units wirelessly related to the instrument. Nevertheless, whereas one can pan and zoom across the picture within the Unistellar app utilizing typical pinch, unfold and swiping gestures, the eyepiece nonetheless solely zooms from the centre of the sector of view.
I disassembled the assessment instrument to find that it’s powered by a 1.4GHz 64-bit quad-core Raspberry Pi 3 Mannequin B+ with 1GB SDRAM operating Linux (the eVscope 1 used a Raspberry Pi 3 Mannequin A+ with 512MB of working reminiscence). Aside, then, from a slightly improved RPi 3 single-board pc, a bigger imaging sensor and the Nikon-designed eyepiece, the interior {hardware} of the eVscope 2 in any other case seems equivalent to its predecessors.
Digital eyepiece
The Nikon eyepiece can be focusable by way of a small wheel on the aspect, so you can also make exact dioptre changes to fit your imaginative and prescient. There’s additionally improved eye reduction for spectacle wearers and fewer optical aberrations. In comparison with the eyepiece of the introductory mannequin, the sky background of the eVscope 2 is a velvet black with out the occasional scorching pixel speckles of its predecessor’s OLED display screen. Moreover, the brand new Nikon eyepiece’s display screen shows richer and extra devoted colors. As an example, I seen that the yellow–orange color of purple giants in globular clusters appeared richer within the eVscope 2 eyepiece in comparison with that of the eVscope 1 and their on-screen look within the Unistellar app. Delicate element and hues within the annulus of the Ring Nebula, M57, and different distinguished planetary nebulae had been additionally simpler to detect within the eVscope 2 eyepiece.
The IMX347 sensor
Once I first learn that Unistellar had opted for a Sony IMX347 sensor for the eVscope 2, I did surprise why they selected a CMOS detector not utilized by any of the massive title astronomical digital camera producers resembling ZWO and QHY. I suppose that I hoped for one thing just like the IMX385 – the extremely regarded bigger sibling of the IMX224 utilized in former eVscopes – or an IMX178, however maybe there have been provide or budgetary elements at play. Possibly Unistellar’s optical engineers felt that their design’s 11-centimetre, f/4 parabolic mirror borders on requiring coma-correcting optics to enhance edge-of-field efficiency anyway.
So the Ring Nebula, M57, got here below nearer scrutiny after I tried to check Enhanced Imaginative and prescient pictures of three minutes length acquired below comparable sky circumstances with each the eQuinox and eVscope 2. Whereas printed information means that the Sony IMX347 sensor has a decrease signal-to-noise ratio than the Sony IMX224 of former eVscopes, the ensuing efficiency when it comes to limiting stellar magnitude seems very comparable throughout the fashions. My empirical strategies agree intently with Unistellar’s printed figures of a limiting stellar magnitude of +18 below exceptionally darkish skies, or a few magnitudes brighter in common circumstances, throughout the product vary.
Tremendous-resolution pictures
Because the launch of Unistellar app v1.3, all eVscope fashions have taken benefit of built-in software program with super-resolution image-enhancement algorithms comparable to those who terrestrial photographers utilizing Olympus, Panasonic or Sony DSLRs (amongst others) could already be accustomed to, specifically as ‘pixel shift’. Unistellar’s implementation works by upscaling (also called resampling) every picture earlier than stacking a number of minutely displaced examples of the identical star area, enabling higher-resolution recording as a result of the overlapping diffraction results of tremendous element could be registered at sub-pixel precision.
The eVscope 2’s Sony IMX347 sensor delivers a 2,048 × 1,536 decision in Reside View mode, which is stacked and internally upscaled to three,200 × 2,400 decision in full-frame Enhanced Imaginative and prescient mode. If one choses to avoid wasting Enhanced Imaginative and prescient pictures with an data overlay, they’re output at 2,800 × 2,800 decision.
Plate-solving plenty of full-frame eVscope 2 pictures revealed a real area of view of 45.3 × 34.0 arcminutes (0.76 × 0.57 levels), or a diagonal measurement of 56.6 arcminutes (0.94 levels). Given the resampled picture measurement, this suggests an upsampled decision of 0.85 arcseconds per pixel, or an precise decision of 1.33 arcseconds per pixel. The latter agrees completely with Unistellar’s printed specification.
Earlier than you get too excited a couple of sub-arcsecond upsampled decision for lunar or planetary imaging, notice that Reside-View captures of Photo voltaic System objects can be on the native 1.33-arcsecond decision of the IMX347 sensor on the focus of the eVscope 2’s 450mm focal-length mirror. As with all of the instrument’s within the eVscope vary, the superresolution algorithms solely work for deep-sky pictures captured in Enhanced Imaginative and prescient mode.
Concluding ideas
The eVscope 2 has a nearly equivalent inner specification to former eVscope fashions apart from the addition of a comparatively cheap, bigger and higher-resolution sensor that lets you totally embody the complete Moon that you simply couldn’t do earlier than.There’s additionally the Nikon-designed digital eyepiece that may be a marked enchancment on the eyepiece provided with the ‘traditional’ eVscope 1.
The eVscope 2’s IMX347 sensor could also be greater, however the tried-and-tested IMX224 chip of former eVscope fashions should have the sting on picture high quality. Even the eVscope 2’s decision benefit is marginal below common seeing circumstances. Therefore I really feel that the eVscope 2 is an incremental improve at greatest – actually not a product that deserves a v2.0 designation or the eye-watering £3,999 price ticket (£4,199 with the backpack included).
Each eVscope is a formidable deep-sky imaging and collaborative citizen science software, however I hoped that Unistellar had been going to enhance the eVscope 2’s lunar and planetary imaging prowess – maybe by the superimposition of some type of inner Barlow lens into the imaging prepare when required. A second-hand eVscope 1 (if you happen to can supply one) operating the newest Unistellar v1.6 app and firmware delivers comparable deep-sky efficiency.
At a look
Aperture: 110mm (measured)
Focal size: 450mm
Discipline of view: 45.3’ × 34.0’
Optical magnification: 50×
Digital magnification: as much as 400×
Resolving energy: 1.33 arcseconds
Limiting magnitude: +17.7
Imaging sensor: Sony IMX347
Knowledge storage: 64GB
Weight: 9kg (together with tripod)
Value: £3,999 (£4,199 with backpack)
Out there from: unistellaroptics.com
