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26 views

Can focal point of a lens be a line instead of a point

Is there any lens OR can we have a lens that will focus light in form of a line instead of a point. Some sort of a rectangular convex lens.
29 views

How did physicists determine how to orient the wave guides for this optical meta lens?

What kind of physics and mathematical tools are used to develop this technology? As described in the link, Researchers have demonstrated the first planar lens that works with high efficiency ...
16 views

Spherical aberration: circle of least confusion and diffraction limited spot size

I need an estimate of the relative sizes of the circle of least confusion (spherical aberration) and the diffraction limited spot size for typical real lenses. I've seen plenty of discussions, but ...
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Coordinate Equation of a curve which bends all the parallel incoming rays from infinity towards a single point

How should i proceed on to find the coordinate equation of a curve such that it bends all the parallel rays coming from infinity towards a single point. Yes I know that it would be a 2nd degree ...
23 views

Lens and Mirror Grinding

I am actually grinding my own lenses ( I am trying). Now I have been continuously using the chordal stroke for atleast 3 hours but i am unable to see any depreasion be it convex or conacve on the tool ...
46 views

Relationship between angular magnification and how much bigger the image appears

How is the angular magnification of a magnifying glass related with how much bigger the image appears to the user? Is it simply the same? If yes, why? (Let's assume that the object is placed in the ...
41 views

If I placed a converging lens in water, would its surface power change?

If I placed a converging lens in water, would its surface power change ? The first case when the lens is in air then placed in water; does the surface power change or remain the same?
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Sun light collimation

Is it possible to make sun light collimated in such a way, to increase energy density and keep it more less parallel? like on the Earth we have intensity of sun approximately 1300 watt/m2. If we use ...
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Calculating f-stop with given focal length and desired depth of field?

I have a varifocal zoom lens set to a desired focal length and at known distance from the subject. I also have a desired depth of field. Given this information, can I calculate a theoretical f-number ...
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addition of two lenses with a finite separation in between

Suppose there are two lenses with focal length $f_1$ and $f_2$ respectively. The effective focal length $f$ when they are combined is $1/f=1/f_1+1/f_2$, but this formula assumes the separation between ...
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Focal length value for infrared camera

I always thought that the 5 mega pixel camera attached to my Android tablet wasn't worthy of seeing the infrared. But I was wrong! The infrared led protruding from my circuit happily shows up it's ...
62 views

Breakdown of Snell [closed]

I have reason to believe the following: If we are using an accurately formed thin prism, with an apical angle of let's say 2 degrees, and direct a monochromatic source beam thru a slit onto the ...
53 views

Calculating the diameter of Jupiter through an image

I took an image of Jupiter through my 8" Dobsonian Telescope, attaching a DSLR and a 1.25" Barlow Lens where the eyepiece goes, as shown in this video: https://www.youtube.com/watch?v=reFxoF3XoaU ...
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Why can't incoherent light be collimated as well as laser light (e.g. in a laser pointer)?

Why does a laser pointer contain a laser diode, and not just an LED? A laser pointer contains a laser diode, which essentially shines coherent light over a large angle, and a collimating lens, to ...
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What is the relative importance of lens element quality in a multiple lens system? [closed]

I tried grinding a custom lens out of acrylic glass (diameter 20mm, focal length 30mm). Not very surprisingly, the result is a quite poor quality lens. I think it mostly suffers from geometry and ...
42 views

Does curving only the inner surface of a diving mask prevent blurred images?

Diving masks often have lenses built into the glass for divers who do not have perfect vision. The lenses in a diving mask faceplate often only have a curved surfaces on the inside glass. Why is this ...
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Tricky Optics Questions, shifting lenses [closed]

A candle is placed at a fixed distance in front of a wall. A lens is inserted and moved slowly between them. At two particular positions, sharp images are formed on the wall. The heights of the images ...
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Optics to correct focal distance across a plane

I have a laser beam which is focused to a point at a certain distance. I'm then going to use a galvanometer to scan that beam across a plane. Obviously, as the beam scans across the plane, the ...
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Why do Photochromatic lenses react to temperature changes?

So, I'm aware that Photochromatic lenses are affected differently due to different ambient temperatures. From what I've read it seems that the molecules rearrange their structures slowly in cold ...
34 views

Where do rays that are not marginal or principal get stopped?

The picture is from an MIT lecture but the concepts are explained in many optical texts. The chief/principal rays go through the center of the aperture stop, hit the edge of the field stop, and the ...
47 views

Covering half of a lens [duplicate]

What happens to the image of an object kept before a lens if the upper half of lens is covered by an opaque coating? I understand that the full image will be formed and only the intensity of the ...
121 views

How is focal length defined for a two lens system?

I have found the formula for the effective focal length $f$ of two thin lenses with focal lengths $f_1$ and $f_2$ separated by distance $d$ to be $\frac 1f=\frac 1{f_1}+\frac 1{f_2}-\frac d{f_1f_2}$. ...
35 views

Splitting an image in a lens into two sources?

Is it possible to project an image of light that passes into a lens onto two surfaces without affecting the image?
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Convex lens with object at the focus

When the object is at the focus, the image will be formed at infinity. What exactly does this mean? What will it look like if you hold the entire apparatus at arms length? Will it be extremely blurry?...
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view angle independant focal point

Is there any way to design a lens or system of lenses where I see the same part of the image below the lens, irrespective of direction from where I am viewing. In the image uploaded, there is a black ...
50 views

Lenses that pixeliate incoming light [closed]

Is it possible to make a lens that 'pixelates' the light passing through it? I imagine a pair of glasses, that when put on, turn the world into a grid of discrete pixels, each having, or appearing to ...
35 views

combination of lenses for undefined focal length

Good morning! I am not an optics specialist, but I need to know if it's possible to do what I tried to visualise in my picture. Basicly I want to merge two beams into one. I am thinking of using a ...
88 views

Why does a specific static image “move” when moving my head? (glass user)

I am a daily PC user. As most users, I have a taskbar (using Windows) that shows icons of programs. My two screens are big (24") and I'm at ~60cm distance from them, so fairly often I need to turn my ...
26 views

How to determine the distance between the principal planes?

How to determine the distance between the principal planes ? If you know the lentgh of both focii, $\overline{FH}$, $\overline{F'H'}$ and additionally the distances $\overline{E1H}, \overline{H'E2}$,...
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Focus correcting screen [closed]

With the rapid approach of VR, and being someone who's always needed glasses! I have been curious about this for a while. Is it possible to correct the focus of a lens by adjusting the image on a ...
33 views

How does magnification work in lensless optical setups?

In my optics classes, I have only ever seen magnification defined in conjunction with the thin lens equation. However, in a lensless optical setup such as lensfree in-line holography, how does one ...
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How lens for specs are manufactured for a given power? Do thickness, refractive index play role? [closed]

I read some where that if the prescribed glass power is more, glass must be made of higher refractive index to lessen the thickness. But from knowledge of physics, power just depends on focal length(...
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What is exactly an ‘virtual object’ ? ( From the point of view of lens maker’s formula )

Here’s an image from my textbook It shows, how an image is obtained from a convex lens. The second and the third images, shows in depth , that how a convex lens behaves. They say, that suppose (...