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A review of the Unistellar EVscope
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A review of the Unistellar EVscope
Well here is another product that has received a lot of hype and press, but without divulging much useful information about the telescope itself. Well needless to say, the hype worked on me….and I took delivery of my (used) Unistellar EVscope today.
Why did I buy, and why should you?
I’ve been in the hobby since I was 13 years old. Over the years I’ve had everything from homebuilt 6F8 newts, to 11” SCTs to Questars and Televues, and you know what? - M13 and all the rest look exactly the same today as they did 40 years ago - so something had to change. I thought about getting into astrophotography as a way of perhaps looking at this differently, but there is a considerable investment in equipment, a steep learning curve, and generally you need to be attendant at your telescope when imaging.
So the EVscope checked several boxes for me.
· GOTO – check
· Self-aligning – check
· Portable – check
· Astrophotography for idiots – check (albeit on a limited basis)
· Ability for scope to operate remotely (ie: me indoors) - check
So what follows is a brief description, first impressions and first-light performance.
What is it?
The EVscope is essentially a Newtonian based camera in
as much as the parabolic 4.5” F4 primary mirror focuses its image directly onto
a Sony IMX224 sensor located in the position that would normally be occupied by
the diagonal in a Newtonian or secondary in a Cassegrain.
The Sony IMX224 is a color sensor with a resolution of 1.2 Million pixels (1305 x 977).
The OTA is carried on a single fork arm ALT-AZ Goto mount with an integral lithium ion battery supposedly good for up to 10 hours. Also packed in there is a lot of computing power as evidenced by the scope’s ability to;
1. Recognize any star field you point it at and derive its internal map from that. (Plate solving)
2. Offer full GOTO and tracking capability.
3. View in both live view (no enhancement) or enhanced vision (EV) which takes frames every 4 seconds and stacks them internally in real time to provide an enhanced vision rendering of the target.
4. Cancel out field rotation that you get with any non-equatorial mounted telescope.
5. Sets up its own wireless network so it can access your phone or tablet to:
a. Get current GPS coordinates and time
b. Send real time pictures to your device (and 8 others)
c. Your phone or tablet runs the Unistellar app which is a free download from Google Play or the Apple store.
The eyepiece is not really an eyepiece in the sense that we’re all familiar with, but a ‘window’ looking at a Hi-res OLED display. You see on this display (and on your phone or tablet) whatever the main Sony chip sees. The sensor image is roughly the equivalent of 50X optical magnification. There is no facility to be able to change magnifications, although can zoom digitally on your device.
However, it is the EV mode that makes this scope different. While it is true that astrophotography has been around for decades, and no one thing that the EVscope does is groundbreaking – the EVscope accomplishes this without all the gear, wires, setup and steep learning curve necessary to get results with a more traditional setup.
It is this ability to capture and stack 15 images per minute with the commensurate increase in brightness and detail of the target that allows the EVscope to make some of its extravagant claims. I have an 8” SCT (which mathematically has 3X the light gathering power) and I can tell you that, with the possible exception of M42, the lowly 4.5” mirror on the EVscope reveals a lot more detail, brightness and color of the Messier and NGC objects when in EV mode – the magic of light stacking vs. raw aperture.
Open box
The EVscope arrived packed in the usual double cardboard box. Well protected. Once you get the outer wrapper off, you will be met with the following promise.
Opening the inner box reveals the following
a) EVscope in parked position
b) Tripod
c) Accessory box for the AC adapter
d) Quick start manual and user manual
First impressions.
The scope and tripod together weigh approx. 20lbs. I wondered what the EVscope would be made of. The answer is aluminum for the OTA tube and plastic cladding for the lower end cell and mount cladding. The fork arm/base /rear cell have aluminum skeletons but in truth is, I was a bit disappointed.
With this scope commanding almost $3000USD, you’d like to think you could get away from the ETX black plastic syndrome, but the scope does have some heft to it, hinting perhaps at a substantial aluminum frame beneath the cladding.
The tripod is basically a heavy-duty camera tripod and the feet are tipped with squishy rubber pads which seem to allow a lot of ‘wiggle’.
Several times I would get the message that the ‘EV mode was dropped due to vibration’. It was a breezy night. I wonder if the squishy feet were allowing too much movement?
The tripod design allows the angle of the legs to be altered from a narrow footprint to almost horizontal in 3 steps. There are 3 ledges that the leg stop can butt against. Just pull out the detent to allow the stop to clear the lower ledge and butt against the next. It is not spring loaded so be sure to re-seat it.
The interface between the mount base and tripod head could also be more rigid. There are only 2 hold-down screws around the periphery, and this allows some movement between the scope and the tripod head. 3 screws would eliminate this issue, and indeed, there is a raised boss in the casting identical to the other two locations that has not been drilled/tapped. This would be an easily fixed oversight.
There is also some unwanted lateral play in the AZ axis. This could be contributing to the vibration warnings I sometimes get. I am currently working with Unistellar to address this issue and will advise the outcome.
Looking down the tube you will see the primary mirror
at the bottom, and the ‘secondary cage’ forming the cross at the top of the
tube where the Sony sensor is mounted.
Interestingly, the tube is double walled.. Whether this is to help with thermal stability, or to hide the wiring going up to the sensor – who knows? The inside of the OTA is painted a satin black which does a poor job of reducing stray light. A flat black paint, or even better, a textured flat black would help the cause.
The overall length of the OTA is a bit longer than a 4.5”F4 system would normally dictate. This is because the secondary light reflections that occur in a Newtonian or Cassegrain design that eat up some focal length are missing in the EVscope. It’s straight from the mirror to the sensor with nothing in between, so the OTA is as long as the mirror focal length plus whatever is needed at either end to house the optics and sensor.
Underneath the mount arm, there are two ports. The
small one (USB-C) is the charging port. The large one (USB-A) can be used for
powering a phone or other USB device from the scope’s internal battery.
Setting up.
The Unistellar documentation is not, well….stellar. It’s bare bones and basically covers taking the scope out of the box and setting it up and how to start the app. Then you’re pretty well on your own.
Spread the tripod and level with the integral bubble level. Plunk the mount/scope into the socket and secure with the two thumbscrews, take off the dust caps and the physical stuff is done. Maybe a minute - tops.
Press the power button about 2 seconds and it will initially turn Purple, and then to Red as it finishes its boot sequence and establishes its Wi-Fi network. At this point you can acquire the EVscope network on your phone or tablet, and then start the Unistellar app on that same device.
Use the app joystick to depress the scope to point at
any open area of sky with visible stars.
A note on the joystick. The center yellow circle is the ‘tip’ of the joystick. Drag it onto any of the four direction arrows to move the scope. The further from the center you drag it, the faster the EVscope moves. Fine adjustments can be made by tapping just the arrows. I found it a little cumbersome to use in practice.
Tap the Autonomous Field Detection icon to start the
alignment procedure.
Once the scope identifies the viewed star field with its internal database (called plate solving) it knows where it is and you’re good to go.
It seems to be very accurate, which it needs to be to land the image dead center on a small CMOS sensor. The only caveat is that it needs to see a star field, not just a single bright star, so you have to wait a little longer for the sky to darken before you can do an alignment.
Tap the ‘Explore’ icon on the lower menu bar to call up the GOTO database. Here you will find most of the popular Messier, NGC and IC targets grouped into several categories. If the selected object’s ‘GOTO’ icon is greyed out, this means it is not viewable at your time/location.
First impressions.
The EVscope is not a fast slewer, and during a GOTO, it seems to pause a couple of times along the way to review its plate solving algorithms in some wayward part of the sky, but whatever it is doing, it’s doing it well as the GOTO’s were spot-on middle-of-field when done, and they stayed there for as long as you want.
During slewing the ‘Live view’ will shows the stars as
streaks until the scope settles down to tracking rates. Once on target, it
stays in Live view mode unless you tap the EV mode icon. The Live view mode can
be pretty grainy on dim objects. You can fiddle with manual controls for the
live view mode to provide a less ‘boosted’ image. I don’t know if dimming the
live view mode also dims the view for the EVscope’s Sony sensor.
So you’ll want to tap the EV icon and this is where the magic happens.
The EVscope then starts taking frames 4 sec apart,
stacking and processing them to present a gradually improving image of dimmer astro
targets. Brighter targets may only seconds to image, dimmer ones may run to
several minutes depending on how dark your skies are.
In my fooling around the first time out, it only needed 20 sec to provide a nice pic of M42 and M82 – the Cigar Galaxy.
And I saw the Crab nebula for the first time ever….
And obviously, from this article, once you have the images on your phone or tablet, it’s easy to manipulate them.
The nice thing about all of this is that other than the preliminary setup, I was sitting comfortably in my den about 25 ft away while the scope was outside in freezing temperatures. I was able to move to the other end of the house which would have been about 40ft away at that point and still had a signal.
The scope seemed to be well focused and collimated when it arrived judging by the star images. Both the focus and collimation are manually adjusted with the app software providing the necessary feedback. There is an included Bahtinov focusing mask located under the front dust cap. Between the mask and the app-based cues for collimation, it is not difficult to do (easier than a standard Newtonian).
A couple of things seem to disorient the EVscope.
1. If there are clouds or obstacles in the way of the FOV, then the scope cannot see a ‘plate’ to solve. It’s not like a regular GOTO where you tell the scope where it is on the face of the earth and what time it is and the controller then predicts the target location from there on. That GOTO system does not care about obstacles, it will cheerfully point at your target on the other side of a barn. By comparison, the EVscope navigates by comparing star fields to its internal maps. If any of the FOVs are blocked when it drops out of warp to have a recon, then the GOTO is aborted, and it returns to tracking mode.
2. If excess vibration detected, the scope will drop out of EV mode. As mentioned, the rubber tripod feet or ‘squishy’ and there is excess play in the AZ axis that may be contributing to this issue…
Conclusions
So far, it is early days, but I am encouraged. The EVscope allows me to view the same old objects in a completely new light (no pun intended) and to save those views to my phone/tablet for use any way I want.
I am able to see things I could never see in my strictly visual scopes, or if visible, as my wife would say….meh...
So instead of doing a Messier marathon and saying ‘yeah, I think I saw it’, you can now have an image of each one for your Messier log. And like our hobby in general, the next night, the seeing or the next image could be better than the last.
The moon and planets can be viewed with the EVscope and indeed, they are GOTO objects in the Apps target list, but it is important to realize that this is not the EVscope’s intended purpose. The EVscope excels at aggregating light and detail from dim objects. The moon and brighter planets will require that you fiddle with the manual adjustments in live view mode. EV mode is not required. Just bear in mind that you are only dealing with 450mm of focal length so the planet views are going to be very small. However, for the moon and bright planets, any decent scope will do.
When it comes to looking for and viewing dim astro objects, there are basically two solutions:
a) Big aperture, with all the attendant problems with portability. And at the end of the day, most faint fuzzies stay exactly like that – faint.. even in bigger scopes.
b) Light stacking ie: Astrophotography. The EVscope is well along the way to astrophotography, albeit with limited resolution and light grasp compared to more professional setups. The meager 4.5” EVscope can show more of deep space objects than you could ever hope to see with direct vision. I’m sure there are some 24” newt owners that would dispute that statement, but please refer to my comment in point a).
So if you want to see more of deep sky objects than is possible with visual observing, and you’d like to be able to take pictures of these views, then this is perhaps a good fit for you.
I know that there are Astrophotographers out there that will sneer at this little scope, and there is no argument that for the money, you could get a much more capable telescope optically, and/or a better resolution AP setup - but you still have to carry it all out, hook it all up, learn how to use it, and accompany it with your computer while you’re taking the pics. And then you need to process the images through various software to tease out the details. I’ve done some basic webcam stuff and then processed it through a couple of stacking programs. I found it time consuming, tedious and not straightforward.
So the EVscope can get you into basic AP without the various components, wires, cables, computers, frostbite and steep learning curve.
I can take the scope outside, set it up and capture a decent image of M42 before the Pro AP guys have even finished carrying all their AP gear outside. And for now, I’m good with that.
EVscope Pro’s
· Good introduction to basic astrophotography. It adds another dimension.
· Accurate GOTOs and tracking
· Fully integrated package so no wires, hookups or compatibility issues.
· Works with any Android or Apple mobile phone or tablet with WiFi.
· Capable of revealing very faint astro objects and saving the image files.
· Good basic App interface. (would be better with a proper manual)
· Very portable (OTA and tripod less than 20lbs)
· No other accessories required.
· Small learning curve.
EVscope cons
· Expensive
· Fully integrated package. If anything fails, you have a paperweight.
· Limited capabilities compared to more sophisticated setups. Reports are that Unistellar is working on upgrades to make their scope more AP friendly for those that want to have more control. After all, it uses the same Sony IMX224 sensor as a couple of popular aftermarket AP cameras.
· Sparse documentation for scope, and, in particular the Unistellar App. (to be fair though, they responded quickly to two questions I asked them)
· Not really intended for the brighter solar system targets (although they can be imaged…)
· Not good for terrestrial use.
- kc6zut, Bob Campbell, chazcheese and 43 others like this
443 Comments
These are some really great images. I hope a device like this brings more people interested in space and science.
The used market will make it available to people who otherwise would not have the opportunity to try something like astrophotography.
I'd like to point out that VR headsets are stereoscopic which creates a 3 dimensional view of the environment you're in.
A used one is what, $2000?
EAA:
Meade Polaris 130 on Nexstar GT* used: $200
ZWO 224 and AISAIR Pro: $530
VV:
Used Orion XT8 Dobs intelliscope w laser collimator, with Orion Expanse 6/9/15/20/40 and 2x barlow: $300
ES 82 11: $200
GSO 2" Superview 20: $50
Rigel Quickfinder: $50
$1330
More versatile, much more fun and flexible for given Bortle.
(*will be upgrading my mount with the additional $670!)
Well balanced perspective. I feel many that compare a list of components offering superior performance completely miss the point. It’s a bit like comparing a gaming PC you can build yourself and tinker with - to an all-in-one iMac that just works out of the box. Different products for different people. I suspect this type of smart scope will hook a whole new generation into the hobby, and will also appeal to veterans who no longer have the time (due to work or family commitments) or ability (due to age or location limitations) to engage in the hobby using traditional equipment. Also a fantastic platform for public outreach by clubs as it’s so portable and quick to set up, and share with up to 10 screens.
+1
There is definitely a place for grab-and-go, easy, no fuss, EAA.
To the OP, we’ll done on the write-up!
Great article! I attended a SETI-sponsored demo of the EVscope last fall. I totally agree with the OP's pros and cons. Loved the idea and execution. (Although I too wish they offered a larger aperture instrument and/or sensor. Maybe soon?)
It's ideal for out-reach events, especially if there's a really large screen available to show a really large audience. At the demo they had a special van with an 80"+ one installed behind a drop down panel. With the panel opened the entire group (a couple dozen folk) could see the screen at once, while several of us also connected our smartphones directly to the 'scope.
Watching M57 displayed as large as my head getting gradually brighter and more detailed over a couple of minutes was... eye-opening. :-)
Our club is discussing getting one for our public star parties and as a "try before you buy" loaner for members. If we do, I'll post notes about our experience(s) with it.
So many arm chair astronomers with scopes collecting dust. The EVscope, EAA, and Vanois Stellina telescope are quite impressive for what they do. I have the Vaonis Stellina and I'm under the night sky on a regular basis. GOTO scope were going to destroy our hobby 25+ years ago. Who wants to do star hopping and setting circles to maybe find any object?
No argument that it could be done cheaper - but it doesn't seem to be easily obtained knowledge about what to buy, how to hook it up, and the various caveats associated with it.
I think that 4s limitation may be imposed by field rotation issues as this is an AltAz mount. It can compensate between frames for field rotation, but not during the actual 4s image. This is only a programming issue - I'm sure that somebody is working on how to cram the necessary tech into a small scope.
After all, pretty well everything over 10" these days, and every large Observatory scope (except the Lick Refractor) are AZ mounts and they are not limited to 4s exposures. It's only a matter of time.
Remember how quickly telex machines were made obsolete by faxes. And how quickly they in turn were made obsolete by Email.
That's where EEA and AP are headed. Not so much that one will cancel the other, but eventually, the differences will become blurred and at that point it will come down to portability, ease of use and cost.
I think your review is very balanced. great work. This scope is not for me but it's good to see that it is bringing people some joy.
One factor that I suspect will drive this is the proliferation of light pollution. More and more area is becoming bright, and it's just going to get harder to drive to dark skies, and then set up all of the gear. I know that using even minimal EAA in my backyard (Bortle 7/8) makes a world of difference. I've seen the Horsehead from my backyard, just by stacking 30 sec frames, no post-processing.
Thanks for mentioning the Citizen Science aspect of the eVscope. The review was unbiased and balanced as others have said. Experienced folks have provided feedback which fairly describes equivalent, or better, systems that can be put together at similar or lower cost. I haven't gone through all the comments yet, so I'm not sure if a couple of things have been mentioned. First, there was a comment about the "limited" database and ability to manually enter coordinates of other objects not included in the current database. The Unistellar app does allow manual Right Ascension and Declination entry for other targets. Second, Unistellar is just about to start shipping a new model, called the eQuinox. It is the same price, same sensor, but does not include an eyepiece for viewing the image being recorded by the Sony sensor. Since the electric eyepiece on the original eVscope has been eliminated in the eQuinox model, you pick up a bit more battery life (1 - 2 hours). There's also more memory on the new model (64 GB versus 12 GB).
One last comment about this product. It is a great asset for doing outreach at public or school star parties. And since there's no eyepiece, the need for others to get close to the equipment is eliminated. Attendees can use their own smart devices to access the images being collected by the scope. There's even an option for requesting control, of the eVscope from a different smart device. My local astronomy club is in the process of putting together EAA setups for club members to use (swapping out the eyepiece for the sensor) at star parties. The images are available on a WiFi network to display the results to smart devices of the star party attendees. A combination of EAA setups, an eVscope or two, and the traditional telescopes with eyepiece views will provide a good range of equipment for conducting star parties.
Unistellar and Vaonis are the first companies to break ground on this type of astronomy (i.e., simplified astrophotography). There will be others that will expand upon this concept and develop improved systems at lower cost. In the meantime these companies are providing the opportunity for followers to build off the lessons learned from these early products.
Yes the evScope & soon to ship eQuinox use 4 second individual exposures. The Stellina uses 10 second exposures. One difference is that Stellina has a built-in camera de-rotator. I don't know but it is possible that the de-rotator allows the Stellina to go longer with the individual exposures. Vaonis also has a less expensive product coming out in about 6 months called the Vespera but that won't have a built-in camera de-rotator (to keep costs down). I don't think they have yet said what duration the Vespera will have for individual exposures.
To date Unistellar and Vaonis are the only companies shipping these all-in-one (EAA) imaging systems. There is a company from China that has a kickstarter project called the Hiuni but it is unknown at this time if they will be able to deliver a finished product. They have not been very good at keeping their backers informed with their progress. At least Unistellar and Vaonis are now known companies with products already delivered and each of them are coming out with secondary products (although the eQuinox is just a minor change from the evScope).
I believe the max 4-second exposure time is to address a minimizing of field rotation? In any case, you would take multiple 4-second exposures which are stacked. In theory, you could stack for hours (as long as the target remains visible). In actuality there's probably little improvement in detail to be gained after collecting stacked images for longer than 20 - 25 minutes (on nebulae). Open and globular star clusters yield good resolution in shorter collection times (less than 10 minutes). Maybe some fainter galaxies are an exception and warrant a slightly longer collection time.
For anyone interested this is an example of mosaic created using this scope. Other examples are here https://evscope.myportfolio.com/
This is the future. This is where goto was 25 years ago. Lou
I hope the existing astro companies (Celestron, Orion, ES, WO, etc.) can react to this and don’t just become niche players. The truth is the astronomy and particularly AP have steep or ridiculously steep learning curves. CPUs are free nowadays, and lots of this stuff SHOULD be automated, or at least combined.
I expect the next generation of mounts might be a computer half/full forks (depending on weight capacity), you attach scope and you just plug in your USB 3 camera into the mount - EVERYTHING else is done within the mount (polar alignment, plate solving, image stacking, image saving, etc.).
I'm not so sure that the eVscope's 4s subs are a detriment (or Stellina's 10s subs). From what I understand about these new sensors, their low read noise neutralizes what was the traditional advantage of long exposures. Rather, I'm seeing more reason to believe that many short subs can produce far better image quality than a few long subs, given the same total exposure time. A few examples of the image quality benefits of short subs...
These advantanges of short subs can produce significantly better image quality than acquiring long subs. For the majority of events that can corrupt a sub, it seems clear that the shorter the sub, the better the chance that the sub will be sharp in detail and clear of artifacts, both of which can further optimize image quality.
In fact, these days it's becoming more difficult to cite advantages of acquiring long subs anymore.
That’s a good analysis. The eVscope (and I assume other smart scopes) will also score the quality of each image and throw out any poor quality subs.
I can see myself getting one of these in the future, not immediate tho. Give it a few years to let the builders refine their product(s).
Very promising product category. I am all for making stuff easier to use and expanding the audience / hobby.
But the eVscope is an overpriced product with deceptive marketing. They have not invented any of the technologies they claim to have. They have just rebranded the innovations the community has come up with and are using this marketing to charge such a outlandish premium to the gullible layman user.
I am sorry if I have offended anyone here but it is what it is. It is clearly dishonest marketing.
But it you are willing to pay the premium and it brings you joy I would say go for it. But do it with your eye open.
I saw an EVScope in action for the first time this past weekend, when a friend set one up next to me. I admit I had low expectations, but we started setting up at the same time and was imaging M3 in twilight while I was still tweaking focus and balancing my Sharpcap settings on my EAA setup. Honestly, by the end of the evening, if it weren't for the 3-grand price point, I would have ordered one.
Searching for other options, I found a YouTube comparison of the EVScope with several DIY set ups. (Created by Dave Hudson - aka "Cosmic Point of View.")
https://www.youtube....D_nQXQw0&t=4s
This guy suggests cheaper alternatives that have more flexibility/adaptability. Of course, the cost of more flexibility is more complexity. Plug and play is not quite there.
I am new to the hobby and I am not encouraged by the lack of innovation by Celeston and the likes. Heck the hand controllers supplied with many of their units are loaded with technology from the 90"s;) Will the legacy manufactures be like Kodak and not be able to keep up with the times? Or perhaps will they partner with ZWO or someone of the likes and provide the optics for an all in one solution?
For me I have accepted the challenge of learning the ropes and using the ASI Pro to help me along the journey, its part of the fun. (In the olden days I used to build computers from the ground up) If that was not part on my journey I would definitely go with the EVScope.
Thank you for sharing your experience and happy stargazing!
A few replies:
Read Noise: I'd like to see some evidence that subs that short are not detrimental.
Transients: Not an issue with if you use sigma kappa clipping. I have also experimented with very weak rejection settings and gotten good results (e.g., one iteration of rejecting 2 sigma outliers).
Vibrations: Sure, these frames would need to be rejected, but spending some of that 2-3k budget on a sturdy mount would probably resolve most of these problems anyway. I don't think I have ever lost a frame due to wind or vibration (at similar focal lengths) on my EQ6-R.
Atmospheric Turbulence: At short focal lengths with multi-second subs, I doubt that this is going to be a big advantage, but I am happy to be proven wrong.
Real Time Progress: You'd need to be satisfied that the auto stretch they perform is showing you what you'll see during editing. Also, live stacking does not depend on sub length. DSS and sharpcap both have a live stacking features that support subs of any length.
----
Some other EVscope thoughts...
Thermal noise: The advantage of moving to a cooled sensor is hard to understate--even when it is not hot out. Going from room temperature to -15C makes a staggering difference to SNR on my camera.
Sensor size: I have tried to use this sensor for deep sky photography and oof. Big sensors cover a multitude of sins, open up huge parts of the sky, and are comparatively cheap.
Ease: You really can't tell someone else what to find sufficiently convenient, and that is the best argument for any time-saving/effort-reducing splurge. That said, I doubt that the primary market for the EVscope is people who (like the author of the review) have enough experience to know what they would find too inconvenient. I think the primary market is people who have little knowledge of astronomy gear and who falsely believe that they would struggle with a normal goto imaging setup + dslr. Again, I won't tell anyone what kind of convenience they should be willing to pay for, but I worry this company is exploiting the intimidating vibe of astronomy rather than tapping an well-informed and convenience-prioritizing customer base.