Questions tagged [imaging]

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Could the phase relation between wavelengths in supercontinuum produce speckles?

Typically, if we use a narrowband laser for an optical setup to image something we observe a picture spoiled by speckles, coming from the laser spatial coherence. Let's say, now I will use a ...
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Questions about first JWST image

Why do the circled galaxies seem to form long circular arcs that surround the white point at the center? And why do most of the galaxies in this image seem to be facing that same point? What is in ...
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Is Terahertz SAR imaging of Earth possible?

The Terahertz band is at the Wavelength range of 1 mm to 100 μm, which is very good for synthetic aperture radar aka SAR since the shorter the wavelength the better angular resolution you get. ...
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How the resolution of an image change when it is out of focus?

do you know if does exist a relationship between resolution and out of focus imaging? For example given a lens, an aperture and a distance d. How can I calculate how much out of focus is an object ...
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Use of Anger logic for sub anode size spatial resolution using pixelated scintillation crystals

Anger logic is widely used as a centroiding formula to spatially locate the scintillation event in multi-anode PMTs (MA-PMT). For pixelated scintillation crystals with pixel sizes smaller than single ...
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Line Spread Function processing

I have measured signal of the x-ray detector through a slit chamber. I need to calculate MTF from it, somehow. I know, that MTF (|OTF|) is a Fourier Transform of the Line Spread Function. The question ...
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Can radar detect electrical fields?

Can we create a radar image of electrical fields, or this is even possible? Do we need a detector opposite the emitter or does reflection work? (see figure.1)
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Semi-Conductor for the imaging array do determine its usability in this application

There are several options: Si, InGaAs, InSb, HgCdTe... But what is the difference in application amongst them?
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So what do we really see in the image of the black hole?

I have already read this question - Orange ring in a black hole image And also have seen several videos about it (Specificaly one from Veritasium -https://www.youtube.com/watch?v=zUyH3XhpLTo&...
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How does MRI distinguish information between in-plane localization and slice selection, despite both using frequency encoding?

A MRI machine can generate 3D image of a human brain. A 3D image have three axis x (horizontal), y (vertical) and z (head-foot). First, a slice along z were selected using frequency encoding. Then, ...
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Temporal vs Spatial Contrast in Speckle Contrast Imaging

I have been reading about Speckle Contrast Imaging recently. Its quite an interesting topic given that it should be possible with relatively inexpensive equipment. The basic premise from what I ...
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How to calculate the energy required for imaging?

Suppose you would like to investigate atomic core structures with atomic separation $x$Å. How do you calculate the energy required for imaging? Say for an X-ray? Edit: Is it simply a matter of using ...
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Reduce subjective speckle contrast while increasing objective contrast

I have been trying to learn more about laser speckle phenomena, and I’m wondering if it’s possible to increase the contrast of objective laser speckles while decreasing subjective speckles without ...
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What vacuum is kept in gen-2 image intensifier night vision devices?

MCPs usually require a vacuum lower than 5e-6 Torr to prevent dielectric breakdown. It seems implausible that small image-intensifier tubes could maintain this level of vacuum for an extended period ...
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Why bi-telecentric lens works with a finite focal length while it should be afocal system?

I bought a bi-telecentric lens for experiment. From all I've learned before, it accepts only axis-parelle incoming beams and exits the same parelle light, so it should be an afocal system with ...
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Entaglement and causality violation. Devices that detect pure states

I have not seen a similar question to mine on the site. Please forgive me if there is any. When I studied quantum mechanics and the entanglement phenomenon, I was told that, although when one wave ...
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How does x-ray attenuation compare to sound wave attenuation?

When it comes to medical imaging (x-ray and ultrasound specifically) there seems to be a difference between the attenuation of sound and x-rays. What I am gathering is as follows: When it comes to x-...
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1 answer
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How pinhole camera works? [closed]

What is the working principle of pinhole camera? What is the function of translucent screen in the camera? Now, if we look behind the translucent screen, what do we actually see: the image formed on ...
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1 vote
1 answer
185 views

Simulate a camera PSF?

Say I have a $3D$ object stored as a $3D$ $\texttt{NumPy}$ array in python. I want to view this $3D$ object as a camera would give: a particular aperture, focal length, etc. My understanding is I can ...
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1 answer
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What is the technology that uses a rectangular mask to do high focus imaging?

There is a newly developed technology that involves using a specialized mask to resolve images without the use of a lens. The technology potentially allows the imaging system to avoid limitations ...
3 votes
1 answer
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Is it possible to take long-distance X-ray images at a high resolution in Earth's atmosphere?

It's my understanding that different wavelengths of EM radiation are affected by scattering and attenuation to varying degrees. Would a camera using only X-rays be able to take a picture of something ...
2 votes
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Why is the Point Spread Function of a diffraction limited lens the Fourier transform of the Aperture Function?

I understand that only part of the spherical wave emerging from a point source in the object plane can be captured by the lens and so only a partial converging wave creates the image as shown on ...
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How do I apply Zernike coefficients to a wavefront?

I have been using the textbook "Numerical Simulation of Optical Wave Propagation with Examples in Matlab" (pdf available online: https://www.academia.edu/42684537/...
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How can the Fourier delta function produce different matrices in single-pixel imaging?

The pattern in the masks used for single-pixel imaging are created applying equation $(1)$, $$P_\phi (x,y) = \frac{1}{2} \left[ 1 +| F^{-1} \{\delta_H (u,v) e^{i\phi}\}|\right], \tag{1}$$ in which the ...
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Is it possible to get a resolution that is better than what is given by the Rayleigh criterion?

I remember reading recently that it is possible to unblur a face that has been blurred by using a computer to process multiple images of the blurred face from different angles. This got me thinking, ...
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Does it makes sense to interpret the Point Spread Function as a volumetric density of energy?

The Point Spread Function (PSF) of an imaging system is its impulse response. Therefore $$ I(x,y,z) = \left[O \star PSF\right](x,y,z) $$ where $I$ is the image, $O$ is the object, and $\star$ is the ...
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How does a transformation domain differ from a spatial domain?

In the context of single-pixel imaging, the following statement is given: "Global transformation has a property that each point (coefficient) in the transformation domain is a weighted sum of all ...
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Why does CW imaging not provide the same data as Pulsed imaging?

"Unlike pulsed THz imaging, the CW imaging (...) only yields intensity data and does not provide any depth, frequency-domain or time-domain information (...)." [1] Why does a pulsed signal ...
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What's limiting the field of view of a lens

An ideal lens with finite aperture leads to the formation of an image in the image plane as \begin{equation}g(x, y) = \int \text{psf}(x/\lambda d - x', y/\lambda d -y') f(x', y') dx'dy',\end{equation} ...
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Glow around objects in AFM image (amplitude modulation mode)

I have made an AFM scan (Amplitude modulation mode) of a sample consisting of polyethylene in a matrix of polystyrene. I have tried to figure out why there appears a 'glow' around the domes of ...
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Imaging aberration

Qs: Doesn't a curved side lens produce less aberration than a flat lens in general because the overall angle of deviation is smaller in the curved lens? Consider the following experimental results ...
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Why does MRI (Magnetic Resonance Imaging) have high contrast and spatial resolution albeit having lower frequency and higher wavelength?

So we've been discussing this in the classroom and I really can't say if my answer to this question is correct since there could be various answers to this. I know that to have a high-resolution image,...
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3 answers
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How to feel energy so I can imagine it? [duplicate]

Please tell me what is energy in reality and how can I imagine it . Please don't rearrange the question . Thanks
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Implement EPR Imaging deconvolution

I have bruker's EPRI data and I want to deconvolute it. I read some article, that says $$ f(r) = x(r) \circledast g(r) \\ F(ω) = X(ω) \times G(ω) \\ X(ω) = \frac{F(ω)}{G(ω)} $$ $f(r)$: imaging spectre,...
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In Quantum imaging with undetected photons, why is the idler photon sent through a second non-linear crystal if it is then discarded?

I've been reading up on quantum ghost imaging and other similar approaches. In particular, I'm reading a paper Quantum Imaging with Undetected Photons by Gabriela B. Lemos et al and trying to ...
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1 answer
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Could we take an image of a fundamental particle?

I would like to know is there any physical limitations that prevent us from imaging a fundamental particle in someway? The Planck length gives us a limit to measurability wrt distance, is this the ...
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1 answer
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Understanding the spatial resolution of a imaging sensor, should it evenly divide the overall image resolution?

I am reviewing the Landsat 1 satellite, specifically its Multispectral Scanner (MSS) imaging system. The system had the following specifications ...
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Should we trust quantum mechanics for working of the mirrors?

In this video, it is explained that it is not necessary that photons obey the laws of reflection and each photon can take any possible path to reach the so-called black hole receiver and all the paths ...
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Determining the size of a light source

I have an incoherent light source that is of unknown size, and I was wondering about the possible methods to measure its size. The issue is that I am expecting it to be very small (few micrometers), ...
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Imaging with A Fresnel Lens

I am in need of an optics expert on imaging, and in particular a fresnel lens is being used as for an imaging device. From my understanding a condenser lens can be considered equivalent to a plano-...
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Imaging with two lenses: what if the distance between the lenses is not $2f$?

A $4F$-configuration is usually utilized for imaging with $2$ lenses. An object is placed in the focus of the first lens ($f_{1}$), then the second lens is located at a distance $f_{1}+f_{2}$ from the ...
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When given magnification alone,for an upright, virtual image, with convex lens, how can I find object distance [closed]

Formula involved in such calculations, similar examples, link associated with d question
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Derivation of image displacement by prism

dWhen white light go through a prism it splits to the rainbow colors. I know a formula to calculate the displacement of an image when light goes through a prism, However, it is not wavelength ...
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1 answer
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Plausibility of detecting viruses using optical spectra [closed]

Ok, this is a huge long shot, and I also apologise if this is a poor question (I'm a newbie here...). This doesn't seem to me a strictly perfect fit for Chemistry.SE, Biology.SE, or Photography.SE ...
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How to interpret the cross-spectral density of an incoherent field

I have been given a definition of the cross spectral density of a completely incoherent field: $$W(x_1,x_2)=S_0\delta(x_1-x_2)$$ How do I interpret this? As I understand it, this means that there ...
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What kind of information does light carry so that brain can "see" shapes and distances of objects? [duplicate]

I know that we actually see with our brain in a way that eyes only absorb the incident light upon them and they transform some sort of information to the brain and the actual "seeing" is done by the ...
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Can this textbook question on angular magnification be answered without a ruler?

This is a textbook question on angular magnification from a chapter on optics and imaging. Note that this comprehension check comes before telescopes are introduced. 12 Figure 15.12 [below] shows ...
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How do modern microbolometer cameras measure absolute temperature of an object?

I recently started working with thermal cameras and I was surprised to learn that they don't give you the temperature value of the object you are looking at for each pixel. So I did some reading. I ...
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Infinity Corrected Microscope Fourier Optics paradox?

I am analyzing an optical system two different ways. One way is using the image formation formula: $$ \frac{1}{d_0} + \frac{1}{d_i} = \frac{1}{f} $$ and the other is using the Fourier transform ...
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VMI image analysis

I used VMI for the photodissociation of O2 and I wonder how I can correlate the radius with the actual velocity of the fragments. Thanks a lot!
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