All Questions
Tagged with optics geometric-optics
1,082
questions
72
votes
6
answers
15k
views
Could a computer unblur the image from an out of focus microscope?
Basically I'm wondering what is the nature of an out of focus image. Is it randomized information? Could the blur be undone by some algorithm?
- 2,613
49
votes
5
answers
13k
views
If a lens focuses all incoming light to a point, how do we get 2D images?
How do lenses produce 2-dimensional images, if a lens bends all incoming rays of light to intersect at the focal point? Shouldn't this produce a single dot of light on a screen placed at the focal ...
- 601
46
votes
6
answers
30k
views
Do people wearing glasses have different field of view than those who don't?
There is one thing I sometimes wonder about ever since I was a child.
Do people who wear eye glasses see objects in different size than those who don't?(Technically different size means different ...
- 8,150
45
votes
4
answers
4k
views
How does Fermat's principle make light choose a straight path over a short path?
This is a thought experiment where I have made a "C" shaped hole inside diamond. The refractive index $(\mu)$ of diamond is 2.45. Say we shine a laser from top of the "C" as shown.
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- 2,000
44
votes
4
answers
277k
views
Virtual vs Real image
I'm doing magnification and lens in class currently, and I really don't get why virtual and real images are called what they are.
A virtual image occurs the object is less than the focal length of ...
- 6,927
41
votes
1
answer
6k
views
How is a (rifle scope) reticle in focus?
The lens zooms and focuses something very far away, yet the reticle inside the lens assembly is in perfect focus just like the far objects. How?
- 463
40
votes
2
answers
3k
views
What is this sort of abstract rainbow?
Today I saw the phenomenon in picture below. It was not raining (at least nearby me). What can that be? What is the technical explanation?
Edit: Just seen today in Southern Brazil another ...
- 17.8k
33
votes
3
answers
3k
views
A Rainbow Paradox
I was studying the phenomena of the formation of a rainbow. In my book, the following diagram is given:
So, the rays at the red end of the spectrum make a larger angle with the incident ray than the ...
- 1,064
33
votes
1
answer
3k
views
Can one determine the speed of the rain from the shape of the rainbow?
I was watching the rainbow today and started thinking about the effects of the rain falling in different directions.
The idea I had was that normally we model rain drops as small spheres, and this ...
- 3,947
28
votes
5
answers
8k
views
Why does a pinhole create an image of the Sun?
When I was a kid I happened to encounter a solar eclipse. I was taught that I should not look at the Sun directly when it is undergoing an eclipse, but I was extremely curious to see it.
Somebody ...
- 2,517
28
votes
3
answers
11k
views
Does light reflect if incident at exactly the critical angle?
A lot of textbooks and exam boards claim that light incident at exactly the critical angle is transmitted along the media boundary (i.e. at right-angles to the normal), but this seems to violate the ...
- 1,174
26
votes
2
answers
4k
views
What is this blue thing in a photograph of a bright light?
It looks like the bulb of the lamp beside it but how why what
- 293
25
votes
3
answers
6k
views
Why is snow white when water has no color? [duplicate]
I just don't get it. Isn't snow just another form of water? Also are all ices transparent or do they go white after a certain temperature?
- 995
25
votes
3
answers
9k
views
Why doesn’t a normal window produce an apparent rainbow?
When light refracts in a prism it creates a rainbow. My question is, why don’t all windows or transparent objects create this dispersion, i.e. why is the refractive index dependent on frequency in a ...
- 969
21
votes
4
answers
7k
views
Spherical mirrors or parabolic mirrors?
I am a high school student and have learnt about how curved surfaces reflect and refract (in "ray optics").
We were always told that these surfaces were spherical in shape, meaning they were ...
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