I grew up with long cold winters, and saw a lot of remarkably transparent ice formed by refreezing meltwater, both in puddles and ponds, and in large icicles. I'd always thought about making optical elements but never tried, as I knew getting a good surface figure would be quite a lot of work.

After clicking through links in this answer to the question Are there any natural materials that can be used as a magnifying lens (or to craft one)? I came upon the images below, which have rekindled my interest.

However I'm currently near the Tropic of Cancer and far from any "Winter Wondernalds".

So I'd like to ask if anyone has ever tried to build a simple, low magnification telescope from ice or if there are any references to such an attempt.

I don't care if it's a front-surface reflector for the Sun or a refractor for astronomical or terrestrial viewing. I'd just enjoy seeing any, even slightly successful attempt at getting some optical magnification from surfaces produced in ice. Conventional eyepieces would be fine, as would projection on a piece of paper.

Some related imagery to "get the ball rolling":

From http://wildwoodsurvival.com/survival/fire/ice/ist.html also see Fire from Ice

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From http://wildwoodsurvival.com/survival/fire/ice/istmake.html

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From http://www.primitiveways.com/fire_from_ice.html

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    $\begingroup$ I think this a worthwhile experiment. The usual secret to making clear glass is to agitate the water while it freezes so impurities and gasses are pushed out of the crystal matrix. Using boiled distilled water is also an aid to clear glass. Nice pictures. Using a mirror to steer your telescope may make supporting heavy lenses easier. Working in a very cold environment with dry air will keep the frost and condensation away. $\endgroup$
    – KalleMP
    Sep 25, 2018 at 18:19
  • $\begingroup$ @KalleMP thanks for your interest. Here's an example of a horizontal telescope with a mirror as you've described: What is the large astronomical instrument shown in this 1918 eclipse expedition photo? $\endgroup$
    – uhoh
    Sep 25, 2018 at 18:30
  • $\begingroup$ You know the spinning "cement mixer" (for lack of a better term) style lenses that are created using molten glass slowly sloshed in a circular pattern? I wonder if something similar could be applied to boiling water to get the desired result of a lens using flash freezing while the boiling water is rotated in the shape of a lens. $\endgroup$ Sep 26, 2018 at 2:29
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    $\begingroup$ Brashear 1886 describes his method for making optics from rock salt, a material also sensitive to humidity but more transparent than glass in the infrared. $\endgroup$
    – Mike G
    Sep 27, 2018 at 20:05
  • $\begingroup$ @MikeG excellent! It turns out that salt was just recently mentioned there as well (I've fixed the link in the question above as well) $\endgroup$
    – uhoh
    Sep 27, 2018 at 20:12

5 Answers 5


I'm not sure it counts as "simple" but there is the ice cube neutrino observatory whose detector consists of a cubic kilometer of very clear ice a mile or so down in the antarctic icecap.

  • $\begingroup$ Ha good one! Indeed it is a telescope in the broader sense (particle detectors are certainly referred to as telescopes in physics, from time to time) and it certainly uses ice. While it's not the answer I am hoping for, I think this is an informative supplementary answer. $\endgroup$
    – uhoh
    Sep 25, 2018 at 13:53
  • $\begingroup$ I wonder what the elevator in that thing looks like, a mile? Does it even have one? $\endgroup$ Sep 25, 2018 at 23:51
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    $\begingroup$ @MagicOctopusUrn there isn't one. The "telescope" consists of strings of photodetectors which have been lowered down holes drilled in the ice, which were then refilled with water and allowed to refreeze. All the operators are based on the surface. $\endgroup$ Sep 26, 2018 at 12:16
  • $\begingroup$ @SteveLinton interesting, so you're SOL if anything down there breaks? $\endgroup$ Sep 26, 2018 at 13:28
  • $\begingroup$ I would guess they can live without a certain proportion of the detectors. Not sure. Or they could drill a new hole nearby and lower another string. $\endgroup$ Sep 26, 2018 at 13:29

I know this string is old, but...for what its worth.

I made a simple lens out of cling film filled with water.

I just laid some cling film over a cake tin ring and poured water into it.

You can adjust the curvature very easily by just lifting the film around the edge and letting more of it fall into the hole - or pulling it tighter. It is basically a slack drumskin. It made a surprisingly effective large lens, but I only could make one at a time.

I imagine you could use this technique to adjust the lens parameters, then freeze it & polish it.

To eliminate bubbles you might want to use filtered and distilled water, and fix some kind of battery driven vibrator to it. (See "Super Ice", which they make for ice sculptures)

If you could get hold of larger circular objects, such as oil drums and find wider cling film rolls I imagine you could make something bigger. (or use any kind of material to make a simple ring. Perhaps a good sized oil drum with several of these lenses might make the beginnings of a rudimentary telescope.

I suppose you could experiment with one based entirely on water - if you could live with the limitation that it would only be any use looking straight up, but the Earth itself does turn anyway, so perhaps, with some calculations you might be able to see something interesting, if you got the timing right - THEN, with liquid proof of concept & adjustments made - that's when you freeze it.

I wouldn't know where to start with calculating lens parameters & parabolas, but that is obviously the natural shape of water in clingfilm.

  • $\begingroup$ Thanks for your answer sharing your first-hand experience, and Welcome to Astronomy SE! "I wouldn't know where to start with calculating lens parameters..." Why not post a new question asking exactly that? You may pick up a few SE reputation points and get an idea how to try it again next winter to get a useful focal length. Maybe you can take a photo of the Moon with an ice lens and publish it here! I'm originally from >40° N but where I live now I'll probably never see freezing temperatures again, so I'm hoping someone else will be able to give this a try. $\endgroup$
    – uhoh
    Sep 16, 2021 at 16:48

This is a coincidence, but it seems that the photographer Mathieu Stern has been thinking about making and using an ice lens for photography for years. The video linked below was just recently released.

See their blogpost and their YouTube video I made a CAMERA LENS with an ICEBERG.

I'm going to call this an "almost" telescope in that a large refracting telescope exposing directly on to a photographic plate, certainly called a telescope by astronomers, is no different than a camera except that it tends to be much larger. (e.g. What (actually) is the " deprojected half-light radius" of this almost-all-dark-matter Galaxy?)

Here are some of the points listed in the description of the YouTube video

  • First of all the life-span of a lens made of ice is very short, so you can't move very far from where you create the lens.
  • Focusing is extremely hard because of the water melting on the lens itslef.
  • Shaping one " lens" takes 45 min because of the ambiant cold.
  • If your lens breaks in the mold, you have to start all over again
  • I hacked a Japanese cocktail ice ball maker to create half spheres.
  • The housing of the lens was made using a home made 3D print model.
  • All photos where shot during the 1 minute of the last ice lens.
  • The video at the beginning of the video was shot in the last usable seconds of the last ice lens.
  • No I didn't ruined my camera with water damages, even if it was pretty dangerous, I managed to keep the inside dry.

I made a CAMERA LENS with an ICEBERG, Mathieu Stern

I made a CAMERA LENS with an ICEBERG, Mathieu Stern

I made a CAMERA LENS with an ICEBERG, Mathieu Stern I made a CAMERA LENS with an ICEBERG, Mathieu Stern

Source: Mathieu Stern


Has anyone ever tried to make a simple telescope using ice?

I have done some research and not found any evidence of an attempt to build one. Another poster has added information on a neutrino telescope that relies on ice. If that's the kind of telescope you're looking for, then there's an example.

Is it theoretically possible to build an optical one? Yes, but I'm not sure what kind of optics you'd get even in the best of (non-melting) cases. Try and see what happens.

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    $\begingroup$ Because you feel it isn't a good idea is not evidence that no-one has ever tried. It could be as a fun project, a crazy challenge, or for reasons you can't guess. For example, links in my question and in the linked answer show many people have tried to make fire-starters out of ice at home where they clearly have better ways to start fire! I have not asked if it would be a good idea because I agree a telescope made from ice would not likely be so useful. Have another look at the question as worded. $\endgroup$
    – uhoh
    Sep 25, 2018 at 13:57
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    $\begingroup$ Bubbles in lenses are not automatically going render the lens useless. Even professional larger camera lenses have a allowable number of bubbles they can accept as the special glasses they use are cut from bulk annealed glass that may contain voids. They just reduce the light and cause some scatter. Galileo had the same in his lenses. $\endgroup$
    – KalleMP
    Sep 25, 2018 at 18:15
  • $\begingroup$ "Has anyone ever tried to make a simple telescope using ice?" - "No." Really? I'd be impressed if nobody ever tried, and more impressed if we could know that for a fact. That's a pretty definitive "No". (Also, there have been an incredible number of things people have done that have no clear benefit...) $\endgroup$
    – BruceWayne
    Sep 25, 2018 at 20:02
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    $\begingroup$ You all are correct in this case. I didn't answer the question. I don't have any evidence that no one has made one. I've corrected my answer. I want to be a helpful member of this site. $\endgroup$
    – Alphecca
    Sep 25, 2018 at 23:14
  • $\begingroup$ I'd already up voted to cancel the down vote when I left my comment. Don't worry about the occasional down vote, it's an open forum. I wish I could try it, but unfortunately, as I say in the question "However I'm currently near the Tropic of Cancer and far from any 'Winter Wondernalds'." which I've just noticed is mipselled. $\endgroup$
    – uhoh
    Sep 26, 2018 at 2:52

What a nice question. Water is easy malleable, to say the least. Ice is very brittle though. But if handled with care you can fine pilish it to get a smooth surface. Of course the ice has to freeze nicely and homogenous. With the less internal flaws. Glass seems to be a liquid. Various pockets of very viscous fluid (church windows of glass "flow" down teasingly slow). If you somehow can get the water in the right shape, freeze it the best you can, and polish carefully, then I see no reason why an icey lens system can't be made. To be used in polar regions (without much light pollution still!).


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