All Questions
Tagged with refraction lenses
133
questions
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24
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How to Calculate Focal Length when in another medium?
How do you calculate the focal length of a lens when it is placed into another medium, if I only have the focal length of a lens in the air? I understand that the lensmaker's equation should be used, ...
- 187
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votes
1
answer
41
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
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21
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Lens maker’s formula from parabolic approximation
I’m attempting to derive the lens maker’s formula for a thin or thick lens using the parabolic approximation.
I’m familiar with the other proof using the law of refraction and different angles.
The ...
- 1
2
votes
1
answer
200
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Lenses and missing reflection
I am wondering why reflected rays are not considered with lenses. If a ray strikes a surface, another is reflected off that striking point; however, this is not added when studying lenses, only ...
- 23
1
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2
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181
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Geometric optics multiple lens focal length calculation
Just wanted to understand how I would go about calculating the effective focal length of these different lens configurations.
There's the combined focal length formula, but I'm struggling to apply it ...
- 21
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votes
1
answer
39
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Magnification of closely packed thin lenses, or of closely packed lens and mirror
I was taught how to calculate the equivalent foci in both the cases. And since the formulae resemble the simple mirror and lens maker formulae, teacher said that this system is behaving like a single ...
- 41
3
votes
1
answer
61
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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
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82
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Plano convex lens refraction angles formula
I am designing an optical device with several plano-convex lenses. In order to determine several measurements I need to be able to calculate the resulting refracted angles at the edges of the lens in ...
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1
answer
44
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As we all know a convex lens doesn't exactly converge all rays parallel to it's axis on a single point. So I want to find one such figure
Writing a differential equation for such a figure is an uncomplicated task. It can be accomplished by using snell's law. But the resulting equation probably isn't solvable. I put it in wolfram alpha ...
2
votes
1
answer
200
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Use of sign convention two times in ray optics
In this particular derivation of refraction happening at a spherical surface in terms of its radius of curvature , image and object distance and refractive index is done by my book as shown
When we ...
- 441
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95
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Focus sunlight into a line and not just a point with lenses
Using a magnifying lens with the sun as the source, one can focus the light in a single point.
Is it possible to use just lenses, or any number of transparent materials of any particular shapes, to ...
1
vote
0
answers
176
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What causes the distortion of an image when seen through a water droplet?
I'm trying to explain what causes an image to be distorted when seen through a water droplet.
Specifically, my example is that of a drop of water on a car window. We can see that the image is reversed,...
1
vote
1
answer
381
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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
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0
answers
126
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Optics question: Simple way to transform a parallel bundle of collimated beamlets into a converging (diverging) bundle of collimated beamlets?
I'm searching for an optical element that converts a parallel bundle of individually collimated beamlets into a converging or diverging bundle of still collimated beamlets (or vice versa). So ...
- 181
2
votes
3
answers
428
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Does using thinner glasses have any effect on how the eye look?
My daughter asked me to buy thin glasses for her eyes. So the power of the lenses are the same, but the glasses are thinner because the glasses use plastic with higher refraction index.
Latter I found ...
- 601