All Questions
Tagged with optics geometric-optics
252
questions with no upvoted or accepted answers
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3
answers
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Images formed by a pair of plane mirrors
I've been taught that if a point-sized object is placed between two plane mirrors at an angle theta with each other, then the number of images formed is $360^{\circ}/\theta$ or $360^{\circ}/\theta - 1$...
6
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Why does sunlight on these windows form caustics with a seemingly hyperbolic pattern?
I noticed these caustics outside my office about a month ago and took pictures: one facing towards the sun and one facing towards the reflective surface (a set of double-paned windows).
The seemingly-...
- 1,200
5
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Is it caustic reflection or hyperbolic projection?
actually last night I noticed a strange form of light rays on the wall of my room which were reflected off a CD. Here is its photo:
Please let me know what is it exactly? A caustic projection or ...
5
votes
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answers
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Finding the illuminance from a triangular light source
Since most light sources in games are point-like, it's pretty difficult to approximate area light sources with point sources. As triangles are a universal form to represent 3D models (thus area light ...
4
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0
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What causes this circular reflection to form?
Holed up at home, I was distracting myself by shining my green laser pointer around. Something particularly interesting happened when I pointed the laser at a reflective black plastic surface. The ...
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4
votes
2
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Location of lens having effective focal length
We know a/c to Gullstrand's equation that the effective focal length of two lenses separated by a distance $d$ is given as $$\frac{1}{f_{eq}}=\frac{1}{f_1}+\frac{1}{f_2}-\frac{d}{f_1f_2},$$ but the ...
- 565
3
votes
1
answer
111
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Refocusing light field images via Fourier Slice Photograph theorem
I am trying to refocus images from a microlens array light field using Ren Ng's Fourier Slice photograph theorem found in his thesis chapter 5, equation 5.7, which is available at https://stanford.edu/...
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3
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Poynting vector flux in a tube (geometrical optics)
Let's consider the following tube (defined as the solid described by two arbitrary surfaces dA1 and dA2, and by all the rays which connect their boundaries):
I read in a textbook that, because of ...
- 1,319
3
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731
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General proof of formulas of geometric optics?
In most lf textbooks formulas of geometric optics like lens maker formula and base formula for that are proven (or rather verified from my point of view) by taking specific case (ray diagram) and ...
- 103
3
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384
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False sunset and false sunrise time estimation
False sunset and false sunrise are described .
Here is a sample day rise and set time according to AccuWheather site and calculated value of sunrise and sunset in my country. Could you please help ...
- 163
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111
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Optics: finding total power of a system, including wavelength
Specifically I need to create an ABCD matrix given 2 radii of curvatures, the thickness of the lens, type of glass (BK7) and a given wavelength. I will have to figure this out eventually, so help ...
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Direction of propagation of extraordinary wave inside a birefringent medium
I am reading Optics by Ajoy Ghatak, in which the author explains the phenomenon of double refraction in a calcite crystal using Huygens' principle. My query is in the analysis of the case of normal ...
- 21
2
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Apparent position of object in bowl of water
Say you have a bowl of water and you keep an object in it. What would the apparent position of an object inside the bowl from the position of an outside observer? Will the curvature of the spherical ...
- 187
2
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Why doesn't a lens after a diffraction grating affect the optical path difference?
When observing interference fringes one often uses a lens after the diffraction grating to focus the fringes on a screen like this:
At first sight, one might think that after the lens the path ...
- 1,692
2
votes
2
answers
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Do Normal Incidence contradicts the definition of refraction?
Professor told our class that if someone wants to define refraction in words, it can be done as the following, The deviation of light from its path when it passes from one medium to another is called ...
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