55 posts tagged with optics.
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Help me build an overhead projector from scratch?

Looking for help with the optics in my from-scratch overhead projector! [more inside]
posted by AutoPilot83 on Oct 17, 2016 - 6 answers

Why do things look darker when they're wet?

Why do things look darker when they're wet?
posted by pompomtom on Sep 21, 2016 - 2 answers

Renaissance Optical Trick Paintings

Can anyone suggest a well-illustrated overview (optimally on the web, or via a YouTube video) of Renaissance paintings achieved via mirrors (e.g. curved/"trick" mirrors) and other optical tricks? Of particular interest: paintings which need to be viewed in a special mirror to be "decoded"?
posted by Quisp Lover on Apr 17, 2016 - 7 answers

Optician nightmare - warranty replacement. How to best solve?

I'm trying to get replacement eyeglasses under warranty. It's been a nightmare process from start to finish, and I'm not sure how to navigate further. More details inside. [more inside]
posted by dubious_dude on Sep 29, 2015 - 8 answers

What material is the third eye of the Cytherian made from?

In the Star Trek TNG ep, The Nth degree, the Cytherian has an interesting material as his 'third eye'. I've had two tiles of it as a kid. It doesn't appear to be a hologram, but looking at it at different angles one sees a lattice of circles/spheres. What is this material and where can I purchase it in larger areas?
posted by oonh on May 26, 2013 - 2 answers

Modular Optical Sensors

In my previous question about photo/optical detectors I received a LOT of great advice and I'm back for more. [more inside]
posted by nickerbocker on May 14, 2013 - 4 answers

Can CCTV predict earthquakes?

In this CCTV traffic video of the recent earthquake in China (preceded by a 30s ad), an interference pattern rolls across the screen just before the shaking occurs. Is this an artifact of the recording (or transfer between media), or something "real"?
posted by pjenks on Apr 22, 2013 - 7 answers

Job suggestions that require acute visual identification skills.

I have severe synesthesia, and part of it means that I hear what I see. Would this be specifically useful in any professional capacity? [more inside]
posted by nímwunnan on Mar 4, 2013 - 14 answers

baby's first slr

Giving my sister my old dslr for her 18th birthday. I'd like to also give her a book that explains the principles of photography. I'd like it to be clear and easy to understand in regards to aperture, depth of field, dynamic range etc. , but I'd also like it to have some ray optics to get her to think about why the camera works the way it does (focal depth, optics etc). Any suggestion would be great.
posted by Large Marge on Dec 16, 2012 - 11 answers

Eyeglasses ID / Suggestions (Metal cylindrical posts)

I am looking for a pair of glasses / companies which produce eyewear which have two metal cylindrical posts as their style. Brands appreciated. I have so far been looking at Oliver People and Salt Optics but would like to broaden my research and options. Any history (who originated it)/name to this style would be appreciated! Cheaper alternatives will also be considered. Examples: 1, 2. Thanks!
posted by nathanm on Oct 8, 2012 - 10 answers

Sharp eyes, sharp eye exam?

Eyes 20/10 with correction, where to get the sharpest prescription in the US? [more inside]
posted by zippy on Sep 17, 2012 - 12 answers

Clear Glasses That Aren't Huge?

In search of clear-framed glasses that aren't massive but are awesome. [more inside]
posted by tmcw on Apr 30, 2012 - 16 answers

Please help me see the light

Please help me find a component photocell (photoconductor) that works well in the IR range. I'm trying to find a photocell that works in the micrometer wavelength range. The market is full of Cadmium Sulfide (CdS), but those peak at a little less than 1 micrometer wavelengths. [more inside]
posted by nickerbocker on Apr 12, 2012 - 9 answers

Free raytracer for optical engineering.

Do any open source raytracers support an output of luminance incident on a surface? I want to determine the distribution of light on a surface in a scene based on the sun position. There are commercial packages that support this, but with the popularity of open source raytracing packages, is there one that can do what I need? [more inside]
posted by demiurge on Jan 23, 2012 - 5 answers

How do positive and negative astigmatism differ?

Why are there two different methods (positive and negative) for recording astigmatism? [more inside]
posted by dmd on Jan 6, 2012 - 3 answers

Hardware mod to fix Automatic Brightness on Android smartphone?

I've got an idea to fix the crappy automatic brightness sensor on my Android phone. Will it work / screw anything up? [more inside]
posted by anthill on Nov 2, 2011 - 8 answers

Why are microscope lenses so small?

Why are microscope lenses small and camera lenses large? Surely having large lenses on microscopes would let you gather more light from the thing you're trying to examine and give you a clearer picture.
posted by Joe in Australia on Sep 3, 2011 - 9 answers

What would Galileo think?

Would it be possible to make a telescope from two contact lenses? [more inside]
posted by Guy_Inamonkeysuit on Jul 29, 2011 - 14 answers

Magical fingerprints

What is this optical effect? It looks like it's transmitting my fingerprints through plastic, but only the fingerprints. [more inside]
posted by BungaDunga on Jul 14, 2011 - 7 answers

Impossible Colors

An optical illusion based on retinal fatigue allowing you to "see" an "impossible color"? [more inside]
posted by darkstar on Jul 5, 2011 - 10 answers

How to find focal length from image magnification % ?

Math/Optics: How can I derive the focal length of a lens from the magnification percentage of an image? [more inside]
posted by ScarletPumpernickel on Mar 13, 2011 - 10 answers

Hey, that isn't a real city!

Why can I tell the difference between an aerial shot and a picture of a model? [more inside]
posted by shesaysgo on Feb 20, 2011 - 17 answers

Art that shows visual effects of looking from close distances?

If you lay your forehead on the palm of your hand and look down at your forearm, you get a distorted view of the connection between wrist and forearm, as well as a sort of "ghost" forearm silhouette at the margins. What's this called, why does it happen, and are there any paintings or other art that captures these effects?
posted by shivohum on Nov 29, 2010 - 13 answers

What causes laser source speckle patterns, and why do they remain constant even if the observer moves?

Why doesn't the speckle pattern that you see around the source of a laser change when you move your head, and what causes the pattern? [more inside]
posted by Bugbread on Nov 14, 2010 - 3 answers

Optical system controllers

I am currently in the process of designing an optical system for my lab and I am looking into different controller options. I'm trying to figure out how to wire different motors, voltage sources, and detectors into a computer. [more inside]
posted by Aanidaani on Nov 11, 2010 - 7 answers

What is this thing?

What are these optical devices? [more inside]
posted by abirae on Sep 21, 2010 - 9 answers

Fecking 3D glasses: Why don't they work they way I expected?

I thought I knew how the current crop of 3D glasses worked, but an experiment with my glasses and my laptop screen proved that something weird is going on. Why does the direction I'm looking through the glasses change what I see, and why do the polarising filters appear to be oriented the same way? [more inside]
posted by metaBugs on Aug 2, 2010 - 7 answers

A tricky trick of the light...

Help me solve an optical puzzle. How might I make this fictional camera obscura work, given the parameters of my fictional location? [more inside]
posted by np312 on Jul 6, 2010 - 12 answers

It's a good thing this never came up on a test

I think I heard a lie from a cave tour guide as a kid, and it's only recently that I realized I took it for granted as a property of optics. Can you confirm this? [more inside]
posted by Countess Elena on May 25, 2010 - 19 answers

Viewing The World Through Two-Colored Glasses

Any harm in wearing sunglasses with two mismatched lenses? [more inside]
posted by Doctor Suarez on Apr 3, 2010 - 5 answers

Lasers and mirrors and fog, oh my!

I have a pretty wicked laser, and I just bought a bunch of mirrors. Help me have fun! [more inside]
posted by MrMoonPie on Nov 24, 2009 - 10 answers


Fourier Optics Filter: Imaging the iphone camera point spread function- possible? [more inside]
posted by Large Marge on Nov 23, 2009 - 3 answers

Stars in my lens

When a camera is focused on a bright light, there is a "star" flare around that light. I've noticed that in different situations, that flare has a varying number of points... What decides how many point the lens flare has? BONUS QUESTION: I've only ever seen even point counts... Can odd happen?
posted by frwagon on Jun 9, 2009 - 8 answers

Find it: Website with a unique explanation of lens focal lengths.

Find-that-website filter: Website with a unique explanation of lens focal length with respect to photography and zoom lenses. [more inside]
posted by odinsdream on Dec 24, 2008 - 7 answers

Bokeh galore

What are some of your favourite bokeh lenses and settings for head-and-shoulder portraiture?
posted by johannahdeschanel on Sep 12, 2008 - 19 answers

No, I won't just mug a FIOS installer

Where can I buy fiber optic cable in a brick-and-mortar store in NYC? Small quantities only. Thanks.
posted by boots on Aug 1, 2008 - 5 answers

What's that material that swaps between images as you tilt it called?

What's the proper name for that kind of image-switching material that switches between two pictures as you tilt it? I mostly associate it with novelty baseball cards, toys, children's books, and so forth. That plastic-y corrugated stuff? If I wanted to order a bunch of postcards printed with it, what am I looking for?
posted by paul_smatatoes on Jun 1, 2008 - 5 answers

Tips for working with optical fiber?

Tips for working with optical fibers (stripping, cleaving, aligning, etc.)? [more inside]
posted by Mapes on Apr 3, 2008 - 3 answers

Is that a UFO or just some guy in a BMW?

I've noticed that many cars seem to have headlights that change colour depending on angle. Is this deliberate or unintentional, and how do I avoid buying bulbs that do this? [more inside]
posted by le morte de bea arthur on Mar 3, 2008 - 6 answers

Are square lenses better?

Optics geeks: Why do some cameras matte off a rectangle in front of the lens like this? [more inside]
posted by Popular Ethics on Dec 3, 2007 - 12 answers

What to do with a ruined zoom lens?

What can I do with a "ruined" autofocus SLR zoom lens? Anything cool/neat I can turn it into? Any fun optics demonstrations I can do with the lenses inside? [more inside]
posted by kcds on Nov 20, 2007 - 5 answers

Light source that compensates for orange mask in negative film?

Let's say I'm toying with the idea of making my own scanner for negative film. I've found a suitable sensor, and the rest of the mechanism looks manageable. Can I get a suitable light source that will compensate for the orange mask, at a reasonable price? [more inside]
posted by Joakim Ziegler on Sep 20, 2007 - 17 answers

How do hybrid EO/IR systems work in UAV applications?

How do hybrid EO/IR systems work in UAV applications? [more inside]
posted by arimathea on Aug 30, 2007 - 2 answers

Optics n00b question

Optics n00b question: I'm working on an art project wherein I etch drawings onto glass and then project shadows of said srawings onto a wall. I've done this before using an overhead projector as a light source and it worked great. This time around I bought some lights that don't work quite as well... [more inside]
posted by garethspor on May 15, 2007 - 7 answers

tap that glass

I'm interested in fitting odd lenses -- and making custom lenses -- to/for digital cameras and digital video cameras. I'm not terribly concerned with the electronic side of things, so you shouldn't be either. What I'm looking for is a crass/crash course in optics -- something (a book, a video, a class, a kit) that will teach me the basics of optics and allow me to force photocopier lenses, telescopes, and microscopes onto unsuspecting recording devices.
posted by fake on Dec 28, 2006 - 12 answers

optics on different cameras, how can I get consistency?

2 different cameras, 2 lenses, how can I get the closest possible recreation? [more inside]
posted by tip120 on Dec 13, 2006 - 5 answers

Weird optics

Let's say I find a shiny spherical object and under point lighting, I move it very close to my eye. I then focus on the bright spot, but focus at a distance of 1-2 feet until the patterns are in focus. At this point, it looks like a bad microscope. Am I looking at part of my own eye? Is this a documented phenomenon I could read about?
posted by aye on Oct 21, 2006 - 19 answers

Peering into the depths of AskMe

Attention optics geeks: Will a flat water/air port affect a lens' minimum focus distance? [more inside]
posted by Popular Ethics on Apr 20, 2006 - 6 answers

Do children see darkness as "blacker" than adults?

Do children see darkness as "blacker" than adults? [more inside]
posted by Bugbread on Apr 9, 2006 - 21 answers

best binoculars?

Re: binoculars. What do I look for and what is the best for my money? We are hiking/mountaineering with kids. [more inside]
posted by snsranch on Jan 30, 2006 - 9 answers

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