As the question says, are there any foil/textile/exotic whatsis that has a mirrored surface but is foldable or otherwise fleixible? I don’t mean reflective like aluminum, but actually capable of reflecting an image like a true mirror.
Try Mylar. Also used in those shiny balloons.
Many flexible plastics can be aluminized and used as mirrors if stretched out flat again, as in the case of abnove-mentioned mylar.
You can make a mirror out of a metal that gets folded, too, but then you’ve got those fold lines and wrinkles in it.
What’s your application?
Variable focal length telescopes: Adaptive Optics
Magic Tricks: Flexible Mirror
Lighting Designer here. As most people know, the entertainment industry uses colored sheets of plastic (called “gels”) to change the color of their lights. One of the major gel manufacturers is Lee Filters (www.leefilters.com). In addition to transluscent color filters, Lee makes a series of reflective media for use in the film industry. It is a flexible sheet material that can be rolled, or folded as you suggest - although folding would impart a permanent crease into the product. Their products are identified by a number, and Lee 271 is their Silver Mirror product. It is available is 21" x 24" sheets, or in 5 foot x 22 foot rolls. Lee’s website indicates that you can purchase through the web site, but I have always gotten my stuff from industry rental and supply companies.
In film, this material is typically used to reflect light from a location where you don’t have room to mount an actual light fixture. However, when stretched out flat, a new sheet of Lee 271 makes a very nice mirror effect. (Assuming no imperfections or creases from folding.)
- OlPeculiar
http://www.leefiltersusa.com/LightPrice/LightPriceSheet.html# (Click on Diffusions/Reflections)
was hoping that there was something like mylar that offered a better image reflection, for an optics experiment I wanted to attempt. But doesn’t seem like.
Ok… time to rework this.
thanks
??
So what’s wrong with mylar? Aluminized mylar (and other aluminized plastic films) makes a great mirror, as long as it’s streched tight and flat. It’s the flatness that determines the optical quality. If you use a foil, as I say, it’s going to get all creased and wrinkled.
What exactly are you trying to do?
If you’re trying to make a concave or convex sirface you can stretch your aluminized plastic film over a circular ring and either inflate it slightly or pull a vacuum. If you don’t distort it too much, it’ll make a decent surface.
Another alternative is to use the surface of a rotating liquid as a concave mirror. R.w. Wood did this with mercury about 100 years ago (Raymond Z. Gallun borrowed it for his SF story “Old Faithful”). I know someone who was proposing doing this with molten alkali metals. The same procedure is used for making some contact lenses, and there are a number of sites on the internet for such “liquid mirrors”. The surface is parabolic rather than spherical (if the motion is smooth, and the rotation axis vertical), but that’s exactly what you want for some applications, like telescopes.
If you go that route, don’t use mercury (toxic vapors) or alkali metals (too reactive). You can get good results with transpasrent liquids for some purposes, or you might try low-temperature eutectics.
More recently (2000): scientists at the University of British Columbia (UBC) have built a 236-inch (6-meter) Liquid Mirror Telescope
…sigh… this is what happens when my brain takes off before my fingers can catch up…
what I MEANT to say is that there was something like Mylar that offered a better image reflection after being folded/scrunched up . Mylar would work admirably if I could guarantee that the stuff doesn’t get scrunched up/scuffed.
As for what Im doing, I want to create a parabolic mirror that is collapsable/foldable and light. I was under the impression that Mylar wrinkles rather easily which would remove it as a contender. If this is wrong, I’d def. appreciate being corrected as otherwise it seems like just what I’d need.
These were big for a few years, back in the early 80’s.
The only qualities that a “true mirror” has is flatness and reflectivity. A mirror is merely a piece of glass that provides the flat surface and a reflective coating applied to one side. Essentially it’s a sheet of metal foil stuck to a piece of glass.
Polished aluminum will make a good mirror. All it needs is to be flat. When I first went into the Army at Sheppard Field, TX the mirrors were polished metal. They gave a good image but they weren’t flat. You got an image sort of like one in a funhouse and shaving was quite an adventure.
I think you’re under a misapprehension about aluminizxed mylar. Unless you deliberately crease it or really press it hard, it’s remarkably resistant to wrinkling. Those akluminized mylar balloons that Anagram sells through greeting card stores, party stores, and the like come scrunched up in an envelope, and they inflate without any wrinkles.
You’re making this all too complicated, really. All you need is a precision optical box coater, then take your injection-molded polymer substrates and give them a reflective surface.
Well in all honesty my only “experience” seeing anyone work with Mylar was an episode of Junkyard wars. Perhaps, I should’ve investigated a bit more. :smack:
Having dutifully learned otherwise, I will now see if I can actually make it do what I’m visualizing. Thanks.
I know this is very old, but it’s worth mentioning:
The great lighting designer Chip Monck once lit a Rolling Stones tour with floor mounted spotlights bouncing off Mylar mirrors, back in the days before synchronized hoists when lifting lights above the stage was much more difficult.
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