All Questions
Tagged with refraction lenses
135
questions
-3
votes
1
answer
53
views
Problem involving lenses and mirrors [closed]
A biconvex lens of focal length 15 cm is in front of a plane mirror. The distance
between the lens and the mirror is 10 cm. A small object is kept at a distance of 30 cm
from the lens. The final image ...
- 47
0
votes
2
answers
122
views
Image formation by convex lens
If an image of an object formed by convex lens is simply meeting of the rays of the object due to refraction,then why do we require a screen to reflect these refracted rays?If we observe the image ...
- 307
0
votes
1
answer
2k
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Finding the Focal Length of a Thick, Plano-Convex Lens
The lens maker's formula takes into account the thickness of a lens. However, if one surface is planar, its focal length should be infinite. But that means that with the below formula, the thickness ...
0
votes
1
answer
115
views
If photon is is emitted in random direction then how does a lens work?
If the absorbed and then emitted photon is a radial wave that later collapses to a random direction (when measured / received) then how does an optical lens work? Can you explain in layman terms (...
3
votes
1
answer
431
views
What is aperture of a lens?
I read that aperture of a lens is the surface from which refraction takes place and it is represented by the diameter of the lens.
So, by saying that the aperture refers to the surface from which ...
- 727
0
votes
3
answers
457
views
Why do refracting telescopes have a wider field of view than reflecting telescopes?
Many websites say refracting telescopes have a wider field of view than reflecting telescopes, claiming it is because their angular magnification is less. Astronomical objects are therefore easier to ...
- 799
2
votes
1
answer
330
views
Chromatic aberration in lenses
We all know that concave lenses act as diverging lenses, but while searching for remedies for chromatic aberration, I observed a concave lens (in the picture see flint glass) acting as a converging ...
- 203
2
votes
1
answer
908
views
How to graphically determine equivalent focal length of two thin lenses?
Suppose we have the schematic above. The first lens has a focal length of 80mm and the second one has a focal length of 60mm, and both are biconvex. My job is to determine, graphically the equivalent ...
- 637
0
votes
0
answers
46
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How to use convex lens to magnify image without inverting
From my knowledge, convex lenses magnify and invert light rays that pass through it. So is it possible to use a second convex lens to make the magnified inverted image into a magnified upright image?
- 1
0
votes
1
answer
3k
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What is the white spot in the sky in this phone-camera photograph?
Consider the image below, taken with a phone camera. There is a white spot near to the Sun, which is dependent on the orientation of the phone. I know it is not a planet nor some sort of star but it ...
- 178
4
votes
5
answers
6k
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Why do we see a blurred image when the screen is not placed at the position where the image is formed by a convex lens?
Regarding the proposed duplicate:
Why does the image lose its clarity when it is formed in front of the retina?
Does the above question answer mine? Short answer: No
Long answer:
Thank you for sharing ...
- 5,306
0
votes
1
answer
2k
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Does focal length of lens change with change in refractive index?
If there are two identical lenses L1 and L2 but made with different materials such that refractive index of one is greater than the other (Say for L1 = 1.33 and L2 = 2.13). Will it affect in any way? ...
- 122
1
vote
1
answer
3k
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How does a diverging lens in a Galilean telescope form an image at infinity when its object is at its focal plane?
This is a follow up question to Farcher's answer for the question - How does a Galilean telescope form an enlarged image even though it has a diverging lens?.
Let us consider the following ray ...
- 5,306
0
votes
1
answer
216
views
How do I make my image sharp?
I created a homemade projector for my phone using a shoebox and a magnifying glass lens of 90 mm focal length. The idea was to put my phone between F and 2F to obtain a real, inverted and enlarged ...
- 1
1
vote
1
answer
1k
views
Can a single optical device converge as well as diverge a parallel beam of light?
A biconvex lens converges a parallel beam of light when the beam is incident on either of its convex surfaces. A biconcave lens diverges a parallel beam of light when the beam is incident on either of ...
- 5,306