The tag has no wiki summary.

learn more… | top users | synonyms

0
votes
0answers
18 views

What is the Index of Refraction of the Liquid Varied with wavelength listed in the question [on hold]

A point source of light sits 0.5m below the surface of a liquid. The source produces a mixture of equal intensity red and blue light. The index of refraction of this liquid varies with wavelength ...
1
vote
0answers
34 views

Constant part of a photo taken [closed]

(56th Polish Olympiad in Physics, II stage) A photographer has a camera with a lens of focal $f$ with can be set to a value from the interval $[f_{min}, f_{max}]$. The diameter of the diaphragm is ...
-1
votes
0answers
47 views

Can a cylindrical lens focus sunlight sufficiently to scorch a surface?

Can a bottle of water, be used to scorch a surface, or is it unable to focus the sunlight enough?
2
votes
0answers
18 views

Interpreting Seidel Aberration coefficients

I am trying to model a simple system in Zemax (though I think the question is general and is not limited to Zemax app), but the ray-tracing does not seem to be consistent with the analysis of the ...
4
votes
2answers
28 views

On unfocused images, their information content and possible restoration

So, when an image is out of focus the light of any given point of the object does not refocus exactly at one point on the screen, but is spread out around a region, such that the light of the image at ...
1
vote
2answers
247 views

Radius of curvature of a lens

Is the radius of curvature of a lens correspond the the radius of the sphere in which the lens rises from?
2
votes
1answer
30 views

radius of curvature and focal length

Is the radius of curvature of a convex or concave lens longer than the focal length of the lens? Does the center or curvature affect the focal point in a lens?
1
vote
0answers
18 views

What is the minimum required length of mirror to view full object if the mirror is convex?

i want to find the Radius of curvature of a convex mirror. i have all the factors to calculate except for image height of an object and image distane. so i can find the image height of an object from ...
0
votes
1answer
36 views

Double slit experiment collimating lens?

In some appratus for the Young's double slit experiment a collimating lens is used infront of the double slits, meaning plane wavefronts hit the double slits. But why do we need/want plane wavefronts ...
0
votes
1answer
43 views

How many foci does a converging or diverging lens have?

I thought this was a simple question but can't seem to find a direct answer. In ray diagrams with a converging or diverging lens, we always draw F (the focal length) on both sides of the lens. But ...
1
vote
1answer
75 views

Optics problem: Determining the new focal length when changing from film to CCD detector [closed]

An older camera has a lens with a focal length of 50mm and uses 34-mm-wide film to record its images. Using this camera, a photographer takes a picture of the Golden Gate Bridge that completely ...
0
votes
1answer
30 views

Ray diagram for refraction

I'm having trouble finding out any errors in a ray diagram. The question is as follows: A ray of light falls normally on the curved face of a semi-circular plastic block, it hits the horizontal ...
5
votes
1answer
72 views

Options to correct rectangular laser beam profile?

We recently switched to a 405 nm laser diode which has a terrible beam profile -- it is a well-defined rectangle with an aspect ratio of about 10:1. The image below shows the collimated beam which ...
1
vote
1answer
55 views

Lens with a mirrored coating [closed]

A biconvex lens of refractive index $n$ and radius of curvature $r$ and focal length $f$ floats horizontally on liquid mercury such that its lower surface is effectively a spherical mirror. A point ...
0
votes
1answer
28 views

What is the formula for determine heating produce by a lens? [duplicate]

When I put a lens along the the sun it convert the sun energy to heat and maybe fire the substance beyond the lens. How could I determine the heat produced and what is the formula?
7
votes
2answers
419 views

How do I find the right lens for my laser?

I purchased this line laser recently and I'm running into a bit of an issue. The laser shoots out at a 120 degree angle which is perfect. However, once the laser spreads to about 4.25 inches, I need ...
3
votes
2answers
59 views

Arrow that changes direction home experiment

I saw this cool optical effect in a experiment on Youtube: https://www.youtube.com/watch?v=G303o8pJzls Could anyone explain to me why the arrow points in the opposite direction? I have read ...
0
votes
0answers
45 views

Is there a way to cancel lens effects?

If I had 2 identical lenses, and put the two facing each other in oposite directions, would their effects be cancelled? Is there a way it could be done, maybe with fresnel lenses, so that it would ...
5
votes
2answers
1k views

Can spectacles converge sunlight to an extent that it burns the eyeball?

I need to know whether wearing spectacles can cause optical harm. I saw a movie where one pair of glasses was placed on table exposed to sunlight, then the sunlight converged and focused to a point ...
1
vote
2answers
71 views

how to trace light after refraction by a camera lens?

I am a programmer and I am doing a camera simulation, I am stuck in a matter of how to know where arrives every ray of light after traveling through the lens and being refracted. Every point of the ...
3
votes
0answers
29 views

What does it mean for a Fresnel lens to have two finite conjugates?

I'm in a situation where I need to reverse engineer a product that my company already manufactures and sells, but it wasdesigned too long ago for anyone to remember. It uses a Fresnel lens with the ...
-1
votes
1answer
131 views

Ways to measure the focal length of a convex lens with only natural sun light [closed]

What are the common ways to measure the focal length of a convex lens with only natural sun light?
1
vote
1answer
65 views

Fresnel lens/kinoform: How to model diffraction at the edges of zones?

I would like to find the intensity distribution of light due to the diffraction at the edges of zones on Fresnel lenses or kinoforms. (That is, location of orders, heights of maxima, etc.) I can't ...
1
vote
0answers
33 views

How to choose a type of a lens for a particular optical component?

With almost no experience in optics, I am trying to create a system that looks something like that: The idea is to be able to focus the parallel wide beam (shown in broken line between lens 214 and ...
0
votes
2answers
35 views

Photographic lenses from the physics point of view

First of all, we need to define the term lens for the question to be totally clear and accurate. A camera lens (also known as photographic lens) is an optical lens or assembly of lenses. [Source] ...
1
vote
1answer
40 views

Lens surrounded by two different materials?

If have a material refractive index $n_1$ then a lens refractive index $n_2$ then another material on the other side of the lens (but in contract with the lens) refractive index $n_3$. How do I find ...
0
votes
1answer
68 views

System of Lenses. Virtual Objects and Nature of Image (Real/Virtual)

We have a certain system of lenses: Lens 1: Focal length: 19.5 cm Lens 2: Focal length : 9.5 cm I put an object 36 cm away from lens 1. Then, I put lens 2 between lens 1 and a screen. The separation ...
2
votes
1answer
234 views

Converging Lenses with Objects at “Infinity”

Whenever we take the case of an object at infinity, we say that the image formed ends up being a point of light on the focal point if we had put a screen right at the focal point. Now, for my lab, ...
1
vote
1answer
113 views

Issue on sign convention with optics

I have a problem understanding the sign conventions used in the equations that describe the imaging properties of mirrors - in particular, when and why should I use a positive or negative number for ...
0
votes
2answers
70 views

How to chose right lens for concentrating IR signal? [closed]

I am looking for the right acrylic lens. Since will be buying at least 1000 pieces I don't want to make any mistake. I want to concentrate the signal from IR LED in a 1cm diameter tube at one point ...
1
vote
1answer
75 views

How does a non-diffracting beam form from a converging ring of illumination?

I am trying to intuitively understand the basics of the supplementary text of a recent publication from Eric Betzig's group on lattice light sheet microscopy (1). I am confused by the explanation of ...
3
votes
0answers
16 views

Colour of artifacts in a lens flare

I'm adding a lens flare to an illustration; which got me thinking: Are the colours of the artifacts (hexagonal/circular) which appear in a lens flares purely random, or much like a rainbow ...
1
vote
2answers
322 views

How to Ray Trace Chief and Marginal Rays in Thin Lens Systems

Looking at the below images, the chief and marginal ray appear to be modeled just fine. But, those lines don't seem to conform to the rules typically used in thin lens ray traces. An example of ...
0
votes
1answer
121 views

Refraction through converging lens: finding image distance and image height

So in this situation there is a 1.79 meter tall person standing 30 meters from a 150 mm converging lens and I'm trying to find where the image will form and how tall it will be. My problem is in ...
2
votes
1answer
165 views

Keplerian Telescope Exit Pupil Location - Whats the Basis for It's Formula?

For a simple two lens Keplerian telescope, this is the formula for the location of the exit pupil: $$z'=\frac{f_2}{f_1}(f_1+f_2)$$ Where $z'$ is the distance to the exit pupil location (i.e. eye ...
1
vote
1answer
458 views

How does 1/f come out as the intercept when plotting a graph of 1/u and 1/v in convex lens?

On this link, in the convex lens second method to calculate focal length. I did not understand how the graph of 1/u and 1/v can give 1/f as the intercept? Could someone please explain?
1
vote
0answers
19 views

Ellipsometry measurments

Why it is good to measure on a wavelength range in ellipsometry instead of using a single wavelength. I understand this that the measured data (ψ and ∆ ) plotted against wavelength and if we have ...
0
votes
1answer
52 views

Broken Thin Lens Algorithm [closed]

We all know the thin lens equation. For $o$ being a horizontal object distance and $f$ being the focal length, the horizontal image distance $i$ is described by: $$\frac{1}{f} = \frac{1}{o} + ...
2
votes
3answers
60 views

What defines camera's size?

Smartphone camera is small while others are big. I know some functions like zoom can change physical size and multi lens,.. etc So, assume that a without zoom, what define camera lens? I want to get ...
1
vote
0answers
68 views

Angular magnification of a two-lens system

Suppose an object is a distance $d_o$ from a first lens (which has a focal length $f_1$), where $d_o>f_1$. Behind the first lens is a second lens with a focal length $f_2$, such as to produce a ...
0
votes
0answers
43 views

Lens parameters / Principal Planes vs. Entrance and Exit Pupil

Under what conditions are the Principal Planes not the entrance and exit pupil? For the definition of Principal Planes see: http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/priplan.html ...
2
votes
2answers
64 views

WHY is a Refracting telescope image distance $S'=-\infty$?

In the above slide, it says that "Eyepiece '2' makes the image distance $S'$ approach $-\infty$." However, What I don't understand is that if I place my eye right at the Eyepiece 2, then I would see ...
1
vote
2answers
1k views

How to calculate magnification

I have various magnifying glasses and I'm using them when I take macro photos with a phone or a camera. I want to group/label my magnifying glasses by their magnification power. And by magnification ...
1
vote
0answers
23 views

Optics - Derivation of Linear Magnification of Lens without Sign Convention [duplicate]

In some posts in this forum I've read that sign convention in optics is useful for making formula memorizing easier, and that we have to use sign convention again while applying the formulae to ...
2
votes
3answers
68 views

In an optical system with a single convex lens, where should the image area be placed in order to take pictures at infinite focus?

I'm trying to learn how camera lenses work, and have gotten stuck. Say that we have an optical system consisting of a single lens with focal length f, and we want to take pictures of objects which are ...
1
vote
1answer
56 views

Is a lens with a focal point that doesn't shift as sun shines from different angles possible? [closed]

My question: Is it possible to manufacture a lens whose focal point doesn't shift in any direction during the day when the sun shines from different angles? It is understood that the focused energy ...
0
votes
3answers
243 views

Image formation (lenses) [closed]

I have a question regarding image formation by lenses. It is the following: A lense with a focal length of $-48.0cm$ forms an image $17.0cm$ to the right of the lense. Where is the object positioned? ...
0
votes
1answer
165 views

An optical system with image from a convex lens forming behind a concave lens

I am having a problem drawing optical ray lines for optical systems. Namely, one which have a formation of image of the first lens beyond the second lens. Take the picture below as an example: In ...
1
vote
1answer
267 views

Creating large aspheric lens profile for CNC cutting out of Acrylic plastic for huge Camera Obscura

I plan to use a CNC mill to cut a plano-convex aspheric lens from a large (300mm dia) thick(30mm) block of Acrylic (PMMA/Plexiglass). I need a focal length on the order of 800-2000mm The purpose of ...
2
votes
2answers
206 views

Interference at the focus of a convex lens or a concave mirror

Now consider parallel rays travelling towards the convex lens. After emerging they get converged at the focus. Won't this lead to interference between light rays? Practically it should but I would ...