Looking for help with the optics in my from-scratch overhead projector! [more inside]
Why do things look darker when they're wet?
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"?
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]
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?
In my previous question about photo/optical detectors I received a LOT of great advice and I'm back for more. [more inside]
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"?
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]
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.
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!
Eyes 20/10 with correction, where to get the sharpest prescription in the US? [more inside]
In search of clear-framed glasses that aren't massive but are awesome. [more inside]
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]
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]
Why are there two different methods (positive and negative) for recording astigmatism? [more inside]
I've got an idea to fix the crappy automatic brightness sensor on my Android phone. Will it work / screw anything up? [more inside]
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.
Would it be possible to make a telescope from two contact lenses? [more inside]
What is this optical effect? It looks like it's transmitting my fingerprints through plastic, but only the fingerprints. [more inside]
An optical illusion based on retinal fatigue allowing you to "see" an "impossible color"? [more inside]
Math/Optics: How can I derive the focal length of a lens from the magnification percentage of an image? [more inside]
Why can I tell the difference between an aerial shot and a picture of a model? [more inside]
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?
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]
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]
What are these optical devices? [more inside]
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]
Help me solve an optical puzzle. How might I make this fictional camera obscura work, given the parameters of my fictional location? [more inside]
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]
Any harm in wearing sunglasses with two mismatched lenses? [more inside]
I have a pretty wicked laser, and I just bought a bunch of mirrors. Help me have fun! [more inside]
Fourier Optics Filter: Imaging the iphone camera point spread function- possible? [more inside]
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?
Find-that-website filter: Website with a unique explanation of lens focal length with respect to photography and zoom lenses. [more inside]
What are some of your favourite bokeh lenses and settings for head-and-shoulder portraiture?
Where can I buy fiber optic cable in a brick-and-mortar store in NYC? Small quantities only. Thanks.
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?
Tips for working with optical fibers (stripping, cleaving, aligning, etc.)? [more inside]
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]
Optics geeks: Why do some cameras matte off a rectangle in front of the lens like this? [more inside]
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]
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]
How do hybrid EO/IR systems work in UAV applications? [more inside]
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]
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.
2 different cameras, 2 lenses, how can I get the closest possible recreation? [more inside]
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?
Attention optics geeks: Will a flat water/air port affect a lens' minimum focus distance? [more inside]
Do children see darkness as "blacker" than adults? [more inside]
Re: binoculars. What do I look for and what is the best for my money? We are hiking/mountaineering with kids. [more inside]
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