Telescope design promises to revolutionize amateur astronomy | Hacker News Reader

Telescope design promises to revolutionize amateur astronomy

phys.org

68 pointsSantosh8348 comments

As someone who has built his own telescope and been somewhat involved in amateur astronomy, this sounds like marketing bullshit to me. It reads like a press release. The first bullet point is especially damning; it's pure marketing speak devoid of any substance. Aperture diameter matters -- that's the total amount of light available. It's why when you want a better telescope, you go bigger. There's no way around that.

Bullet point #2 is nothing special; it's just using GPS for location and a clock to automatically point your telescope at a specific object. This has been around for a long time.

Bullet #3 appears to be talking about image-stacking, which, again, is a technique already commonly employed -- put your telescope on a computer-controlled equatorial mount, take many 30 second exposures (typically the max allowed by a DSLR) over the course of hours, and combine them in software. And I seriously doubt that you can get much utility out of stacking images taken by different telescopes in different viewing conditions.

Aperture isn't just the amount of light, but also resolving power. A small aperture with a long exposure might show you a DSO, but probably at >arcsec resolution.

But - this makes it accessible. I don't think you can say the same for pixinsight, dss, phd, etc. - there's a fair old learning curve to do it the proper way.

Yes, making the features easier to use is always a good thing of course, and many a company has become a successful player in its field not by inventing new things but by making existing things more accessible.

What I don't like about the press release is that it makes it sound like they've come up with all these new revolutions in astronomy, which near as I can tell they haven't done at all.

I guess it depends on how you define "revolution".

I can clearly foresee how this might lead to 100x more people getting into astronomy. The current amateur experience is to look at the Moon, look at Jupiter, look at Saturn's rings, and then put the telescope in the attic. Once this real-time image-stacking telescope that works just like an old fashioned "dumb" telescope is refined, the experience for amateurs will be so much better.

So I would call this "revolutionary", in that if you graphed the # of amateur astronomers, I could see this being a critical non-linear point where the line shoots up at a much faster rate.

So a "revolution" for experts? Probably not. (Although perhaps even experts will get a lot out of the speed and simplicity of it). But for astronomy as a field, possibly.

Here's hoping. I'm not quite that optimistic about it as you are, but I'd love to be wrong!

About #2 - I think the 'new' part they're touting here is no longer needing to ensure the telescope knows exactly where north and the horizon are. In other words, given a known location from GPS and some images of stars from the builtin camera, it'd be possible to calculate in which direction (az/el) the telescope was pointing. Is there a general term to describe this sort of thing?

Self-calibration? Automatic alignment? Real astronomical telescopes have been doing that for forever, even by hand since before computers existed. A compass is just never accurate enough (and magnetic north isn't a constant besides).

And yes, there are telescopes already available in the thousands-of-dollars range that calibrate themselves by combining data from GPS, the time, and sightings of a few specific stars. See e.g. http://www.celestron.com/university/astronomy/skyalign-(us-p...

> Aperture diameter matters -- that's the total amount of light available.

I think the point is the implied 'at that instant' which can be appended to your statement. Aperture matters in the context of a specific shutter speed.

You allude to that 'aperture is everything' loophole in your comment on bullet point #3, about image stacking.

It also matters for resolving power though. You can take photos using a 1 m telescope with a one second exposure that you could never take using a 10 cm telescope at any exposure length. Keep stacking the photos for years, you're still not going to get the same detail.

This is why the latest generation of land-based optical telescopes have truly mind-boggling apertures. Bigger is better in astrophotography, full stop. https://en.wikipedia.org/wiki/Extremely_Large_Telescope

Are you suggesting astrophotography has physical constraints that non-astro photography does not?

More specifically, to your example, if a 1m (diameter?) telescope takes a photo with a 1s exposure -- you're suggesting that it will resolve more detail than one taken on a 10cm lens for 100 seconds?

It's the same across all astronomical telescopes.

And yes, resolving power is dependent on the size of the aperture. You can't make it up for it by combining many photographs taken with a smaller telescope. More information here: https://web.njit.edu/~gary/202/Lecture6.html

The resolving power of a 1m scope isn't 100 times that of a 10cm scope. It's 10,000 times as much. Pi d squared.

But I think the issue is that with super long time exposures things like lens and mirror aberrations, cumulative drift and rotation over time get magnified as well. As the exposure gets longer, the incremental benefit you get from each unit extension of the exposure decreases.

Also, if you take 100x as long to do an observation, that's a hundredth as many observations you can do in any given amount of time.

>Are you suggesting astrophotography has physical constraints that non-astro photography does not?

No, he's saying the diameter of a lens affects its resolving power. This is due to the diffraction of light bouncing off the lens. Larger scopes have less diffraction due to the laws of physics.

Lenses aren't used in "real" telescopes -- they're made out of mirrors only. Does your explanation still work?

The mirrors in telescopes are still lenses. You're probably thinking of refracting lenses as being "real" lenses. But the parabolic mirrors used in telescopes accomplish the same task. And, yes, diffraction is still just as much of an issue.

Out of curiosity, have you ever made your own mirrors/lenses ?

I have ground my own primary mirror, yes. Even wrote a series of blog posts on it a long while ago: http://www.cydeweys.com/blog/tag/amateur-telescope-making/

Grand !

Apparently it does the equivalent of image stacking in "real time" as you look through the electronic viewfinder - no new tech involved, but a big win in cost/complexity nonetheless.

It literally is a press release:

http://www.seti.org/seti-institute/press-release/seti-instit...

Much or all of the content on phys.org is press releases pulled from science related institutions.

> Enhanced Vision produces extremely sharp, detailed images of even faint astronomical objects by accumulating their light and projecting it into the telescope's eyepiece.

So... it pretty much works the same way every other telescope works? I read the whole article, but couldn't find a single detail about how it can actually resolve better than other telescopes of its size.

The video shows an augmented reality overlay. If that's what it's all about, then I'm really not impressed (if I wanted to see images other people have taken, I wouldn't be using a telescope). Let's hope that's not what they're referring to when they say "Our compact 4.5-inch telescope allows observers to see objects fainter than Pluto."

I read it as image stacking and an electronic viewfinder. Presumably B&W only.

I didn't read it that way, but that makes perfect sense. I don't really see another way they can sell it for less than $1k as the article indicated.

Ah, that does make more sense, though you'd think they could mention it if that's what they're doing :)

It doesn't sound as magical if they say how.

Their eyepiece images show color: http://www.unistellaroptics.com/en/blog

I think that all they've done is integrate a CCD with automated stacking into a newtonian.

I wouldn't exactly call this revolutionary, as amateur astronomers have been coupling cameras (film then CCD) to telescopes for a century - but if it makes viewing DSOs more accessible to junior-amateurs at a good price point, then that's no bad thing.

I've just replaced my entire astronomy setup as the mount was getting old and cranky, and it has involved ordering about 40 distinct pieces of kit, with a lot of knowledge required, so I can certainly see the appeal in a push button solution for casual observers.

I've spent the last several months building a platform to solve problems #2 and #3 with a (mostly) software-based approach. The controller is built on a Raspberry Pi, and it can control any servo-controlled mount or camera that is supported by OSS tools like Open Sky Imager, PHD Guider, etc.

I think this is preferable to a pure hardware approach because people can use their existing equipment, and they don't have to make a major upfront investment in something proprietary. The initial cost (for the controller) should be under $100.

My goal is to make astronomy more accessible to folks without deep pockets or STEM backgrounds, and to increase the pace at which we make discoveries in outer space. If anybody's interested in contributing to this project, or participating in the beta, please drop me a line (@freerobby on Twitter, or robby@freerobby.com).

More about my thinking, motivations, and plan can be found here: http://astroswarm.com/2017/02/12/making-space-easy-to-study....

Alright so according to many comments high end telescopes costing thousands of dollars already have such features, or it possible to combine different products and systems to do the same thing. Fine.

The article isn't claiming anything unique, other than providing this as a single integrated product at an unprecedentedly affordable price. Is that wrong? I honestly don't know. The way I read all the negging I'd assume there are already products just like this at similar prices. Are there?

I honestly don't know. Just asking.

Quick search on Amazon seems to reveal some results.

I am the target market for this. I recently rented a cabin that had a standard telescope and although I knew exactly where Jupiter was it still took me 20-30 minutes to line it up just right. 5 minutes later a cloud moved over it. No one else got to enjoy it.

I need something pre-assembled, easy to use, and at or below $1k. Although I could deal with some assembly, this is not something I want to have to troubleshoot when the sky is clear and the urge to stargaze strikes)

There are plenty of options. Here's one: https://www.amazon.com/Celestron-Nexstar-Schmidt-Cassegrain-...

Thanks for the suggestion. After poking around a bit I realized I probably need to factor in weight as well. Good news for me since lighter is cheaper.

Here is a FAQ:

Q: isn't this physically impossible? Surely it has to be based on EVF with Stacking/Long exposure?

A: well of course.

This is an ad. What's it doing here?

Slightly more information: http://www.unistellaroptics.com/en/product

> Enhanced Vision produces extremely sharp, detailed images of even faint astronomical objects by accumulating their light and projecting it into the telescope's eyepiece. Enhanced Vision technology mimics the light gathering capability of significantly larger reflector telescopes

> Our compact 4.5-inch telescope allows observers to see objects fainter than Pluto and achieve sensitivity equivalent to a one-meter telescope!

These claims are impossible for a direct-view optical telescope. But do they imply that they are accumulating photons on an image sensor and showing the image to the observer electronically - basically long exposure photography?

On a side note, the web page hijacks clipboard copying and inserts a source URL.

Yes, looks like it's long exposure photography but with the resulting photos displayed in real time:

"Turn Light Amplification on and the system will use its low-light sensor to accumulate light through a series of short exposures. The resulting image is projected into the eyepiece as the accumulation occurs, which means that once you start Light Amplification, you’ll see something, but the object will keep improving with time."

Pretty neat idea.

That doesn't seem particularly revolutionary to me though. You can already do this with existing software used for image-stacking, though not directly through a viewfinder (though the "viewfinder" on a real telescope designed for astrophotography should be a computer display anyway).

That's a very good point.

I think what's revolutionary about it is the speed and simplicity. Sure, you can do this already with image stacking software, if you already know what you're doing or want to spend 600+ minutes learning how to do it. But this promises to just point and shoot and see almost equivalent results in near real time, a speedup of ~100x. So a two order magnitude speed improvement for the novice is a big deal, imo.

Yes, that does seem nifty. And it'll be good for pure stargazing scenarios, in which you're not attempting to record an image. For astrophotgraphy, however, it'll be a wash, as all you need a viewfinder for in those situations is to ensure that you're pointed at the desired object; the final output is always going to be best viewed on a proper display.

I suppose what this is really doing is bringing the benefits of some common astrophotography techniques into casual stargazing, which is cool. Too bad the press release doesn't explain it properly.

> Too bad the press release doesn't explain it properly.

Agreed.

Wasn't until I read the actual site (http://www.unistellaroptics.com/en/product) that I got excited.

Yeah, that's way better, and is actually something that might excite people who are into astronomy. The original article was written by someone who simply didn't know what they were talking about at all, and used copious marketing speak to try to make up for it.

Well, I'm guessing it will have something similar to the digital viewfinder you see in modern cameras.

If you use that together with a medium range camera and some basic computing (or dedicated chip) to stack and remove noise from images, what they are claiming seems doable, as long as you are under good astronomical observation conditions.

A few years ago I saw a project to 3d print high end telescopes using smart phones to process the image at a maker faire. It was an open source design, I think this one

http://www.openspaceagency.com/ultrascope/

For myself although I'm not an amateur astronomer I think I would be more interested in something I could make/tinker with myself.

Real-time image stacking can also subtract out light pollution. Imagine seeing the full width of Andromeda, 6 moon widths across, above suburban school grounds even on moonlit evenings. This will be an exciting way for kids to encounter astronomy.

Soo... anything about price or ETA?

Right in the article. Crowd-funding starts this Fall, for "less than $1000".

Advertisement for a toy, accidentally posted on wrong website.

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