All Questions
103
questions
0
votes
0
answers
14
views
Can the eye lens not produce a virtual image when the object is between Focus and Optical Centre?
My teacher dismissed the question saying it is not possible for the eye to do so simply because we didn't know the focal length of the eye. That confused me. The focal length can vary, sure. When we ...
- 351
0
votes
1
answer
23
views
Exit Pupil, Objective Aperture, Magnification, and Brightness
Why is it that for two pairs of binoculars, with equal aperture, the one with smaller magnification has larger exit pupil and results in brighter images? If I understand correctly, the aperture ...
0
votes
1
answer
45
views
What is a convex-concave lens?
I came across this term while studying for optics, and I'm unsure as to what this means. My thinking is that it might be a meniscus lens, but the text separately give two different models for each ...
- 187
-1
votes
2
answers
62
views
Why is a bigger camera sensor better at low light than a smaller one?
People say a bigger camera sensor is better for light performance as the photo sensors are bigger and hence let in more light. But couldn't you just let the same light in and focus it down onto the ...
- 113
1
vote
2
answers
64
views
Conflicting lensmaker's equation representation
I keep finding these two conflicting forms of the lensmaker's equation. I understand that (n2-n1)/n1 is the same as (n-1) if referring to a lens in air, but I can not make sense of why the reciprical ...
- 23
3
votes
1
answer
62
views
Can a system of lenses or compound lens have a higher numerical aperture than a single element in the system?
I am attempting to create a simple Abbe condenser for a microscope, which typically consists of two converging lenses.
Ideally, I would like to achieve a numerical aperture for the condenser of ...
- 33
0
votes
0
answers
30
views
Is it preferable to say $v$ is " image distance " than to say " image position " in spherical mirror formula?
I was going through spherical mirror formula $1/v + 1/u = 1/f$ where $u$, $v$ and $f$ are named as object distance, image distance and focal length respectively. But while using this equation we do ...
- 1,357
0
votes
1
answer
56
views
Optics: How does lens prescription work for near vs. far distance?
I don't have any physics background aside from intro physics so apologies if my question sounds very shallow.
If lens power is based on focal length, but our eyes adjust its focal length based on the ...
- 3
0
votes
0
answers
108
views
Is it possible to make real DIY microscope with several lens?
I have alot of small double convex 7 mm lenses and i have very small lens 4mm
And i have plano concave lenses all of them is small
I tried to combining them to get a magnified image and it worked when ...
- 101
1
vote
2
answers
150
views
Why didn't I reach $\frac{1}{p}+\frac{1}{q}=\frac{1}{f}$?
In optics for convex and concave mirrors there is the following formula: $$\frac{1}{p}+\frac{1}{q}=\frac{1}{f}$$ where $p$ is the distance between the object and the mirror, $q$ is the distance ...
- 402
0
votes
1
answer
77
views
Why does bright objects make less bright objects invisible?
I was walking by the sidewalk during the night when I noticed a swarm of flies circling a street lamp. It was difficult to see at first, so I tried looking in different angles. The security gate came ...
- 12.5k
1
vote
1
answer
398
views
Deriving the focal length of a graded index lens (GRIN)
I want to find a closed expression of the focal length of a graded index since I don't manage to find any on the internet. I already checked this out: Determining the focal length of a gradient index ...
- 344
0
votes
1
answer
790
views
Lens makers formula [closed]
I am using sign convention while deriving the lens makers Formula but, in doing so, I am Not getting the correct formula for it. But when i derive the same formula without sign Convention it gets ...
- 121
0
votes
1
answer
61
views
Paraxial Rays and Curvature of Field
In these slides it is stated that:
Most optical tend to form the image on a curved surface.
Well, the thin lens imaging equation states that it maps an object plane on an image plane. Of course it ...
- 1,319
0
votes
1
answer
53
views
Paraxial Rays and Coma
In these slides it is stated that:
Coma is an abberration that afflicts off-axis light bundles in a
similar manner to the way in which spherical aberrations affects the
axial bundles.
About Coma, my ...
- 1,319