Imaging Definition and 146 Threads

The widely recognized theory for the detected image in microscope (I believe) is calculated by taking the convolution of the object and a point spread function (PSF). Deconvolution tries to reverse this operation to get back the original object. This explanation sounds easy and intuitive but...

Sometimes I win at eBay: On the right is a Ehringhaus quartz compensator in perfect condition- I believe the seller didn't know what they had, I got it for $200. Now I need to learn how to use it :) It seems that whatever I decide to learn how to photograph, @davenn has been there already...

Objectives: - best path for optics needed to focus and "draw"/project a high resolution image onto a workspace around 500mm square (for a Laser Direct Imaging machine) - where to cost effectively purchase or make the optics necessary to build a prototype The problem: I need to project a high...

What kind of imaging system could be used to see without photons? I ask because I was watching a video and the furthest we can see back is Redshift Z~1090 which is the CMB. We can’t see the universe before the first stars formed or the Big Bang itself. My first guess would be some kind of dark...

Does anyone know why this mirror imaging happens?

Question: Answer: I don't understand about a and c. I just tried to solve b but my answer is still lacking for part b. Can anyone guide me about how to solve these problems and what I did wrong in part b.

a. lambda = 513 X 10^-6 m ZR = 1, 2 cm Z = 1 cm => Z < ZR => LR = D = 0.5 cm Z = 8 cm => Z > ZR => LR = 2 tan(sin^-1 (lambda/D)) x Z = 2 tan(sin^-1 (513 x 10^-6 m/0.005 m)) x 0.08 = 1.65 cm b. t = Z/c...

Textbook examples usually involve a plane monochromatic wave that is diffracted by a plane grating. If one places an ideal focusing lens behind the grating one will get a diffraction pattern in the back focal plane of the lens. The geometric size of this diffraction pattern is proportional to...

Here is my answer: PART A: Those three didn't surpass 200 us. But, I am still wondering whether I did it right or not since I don t really understand the meaning of `multiple reflections `. I don't know whether I have answered for multiple reflections in my answer above. or should I double the...

Hello Everyone, I have a thermal imager and I am interested in better understanding night vision (NV) technology. Apparently, NV goggles respond to NIR and SW See this article. NV goggles can see from the near infrared (NIR) to the shortwave infrared (SWIR) portions of the light spectrum. Do...

Last night, (3/23) I read this article, alas, today it has disappeared behind the inevitable paywall. (this means it's a good piece) If you have access to Nature articles, this is a fascinating read. A huge advance in Geophysics that will see a lot of attention in future geothermal studies...

what is fluoroscopy mode in cardiac xray imaging?. simulator shows EP,LF,MF,HI(extra low fluoroscpy, low, medium and highfluoro.what is it actually means?

"B0 is a static magnetic field (produced by a superconducting magnet) that initially causes the protons in the body to align with the field and precess at the larmor frequency along the z axis . From a mathematical perspective this precession around the B0 axis occurs due to the time evolution...

I was wondering if radar is safe, can it detect near objects (lets say 50 feet away) and does it accurately see 3D shapes? I am looking for a technology that could maybe supplement augmented reality in the sense that VR objects can be given GPS locations, but don't know if there is something in...

Hello all. I have a question about building the coherent transfer function and specifically how I would go about deriving the pupil function for this figure. I have not come across this in my class yet and am a bit stumped. Any help would be appreciated.

Hello folks, I have the two following questions I'm working on: Q1 An optical microscope uses a lens with NA = 0.7 and a focal length of f = 20 mm. What is the smallest spatial distance that can be resolved if a wavelength of λ = 633nm is used? An iris is introduced in front of the lens with a...

After many months what comes out of the mouth and nose of someone infected with Covid 19 has not been directly observed. A single virus particle of Covid 19 is about 120 nanometers in diameter. This means that to see the virus, visible light wavelengths of 400 nm to 700 nm are too long to...

Hello All, 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-convex lens. Setup: A condenser fresnel lens is used, for which both the fresnel and...

If i put a rotating stick behind lens of several types, so the stick center is behind the lens center, will the stick edges always appear to move at the same rate as areas closer to the stick center?

What are some good books which covers topics like diffraction tomography, inverse scattering, RF imaging and Fourier optics?

I was reading that in inverse scattering approach, we divide the region of interest into discrete grids and size of each grid should be much smaller than the incident wavelength (usually smaller than one-tenth of wavelength). By this logic, theoretically, I can use inverse electromagnetic...

Any object with a temperature emits corresponding EM waves. Thermal imaging works by considering our temperature of 37C/98.4F/310K, and it corresponds to 9.3um LWIR as per Wien's law. I was thinking about the following summer scenarios in which how it would work. 1) If...

Hello! I am a bit confused about the image reconstruction for velocity map imaging. As far as I understand, at the interaction point, ions are produced in a Newton sphere which gets projected on a 2D screen (such that all the particles with the save velocity get mapped on the same point). What...

There are galaxies that are so far away that metric expansion causes them to have a co-moving recessional velocity that exceeds the speed of light. However, those galaxies are also so far away that the time it took the light to reach us was itself billions of years in the passage of its journey...

I tried the method of https://www.researchgate.net/publication/320344649_Synthetic_Schlieren_--_application_to_the_visualization_and_characterization_of_air_convection Instead of their "checkerboard printed on a transparent plastic sheet and back illuminated by a led panel" I made a checkerboard...

Hey! So, I took images of NGC 7741 at school using CCD Soft. The field view looked exactly how I would expect when aligning to my galaxy, so I'm almost 100% my galaxy will show up once I stack my images ( I took a set of 20 with 1min exposure). I tried to check by stacking through PixInsight...

Hello all, I want to use a laser beam as a straightness standard for use in measuring flatness of a machine guide way which is about 2 meters long. I'm envisioning a low power laser pointed at the sensor of a digital camera which moves laterally along the imperfect guide way. The waviness...

In this article, researchers have used electrons to image light as both particle and wave at the same time. https://phys.org/news/2015-03-particle.html

Homework Statement We want to image carbon C14 atoms using NMR with magnetic field of B=3 T. What frequency do we need to use? Use the following facts: C14 has 0% abundance, nuclear spin of I=3 and g=0.273 Homework Equations The frequency is given by f= (2⋅I) ⋅ (g ⋅B ⋅μ)/(1836 ⋅h), where μ...

I have a very very unusual project requirement where I need a pocket video projection with the lowest possible projection angle or "longest possible throw-ratio". It's a pocket DLP projector so goal is to have the beam remain ,as much as possible, almost the same size as the DLP matrix, for a...

I'm reading about the theory behind MRI, specifically from Farr's Physics for Medical Imaging, 2nd Edition, by Allisy-Roberts and Williams. According to this book, the spins of the free protons in a sample line up, either parallel or antiparallel, with the externally applied magnetic field. In...

Is there any sensor or method that allows a 'photo' to be taken of sound from different places? Similar to an ultrasound that is used in the medical field, but can be used more like a camera. I know about Schlieren Imaging but I'm thinking more like a map of all the sounds at a moment, maybe...

Worked with visible, infrared and multispectral imaging systems. Developed image based and laser ranging based 3D imaging systems and associated data analysis systems for CSIRO (Australia). The image based system (essentially SFM) was commercially released as Sirovision. Subsequently broadened...

Greg Bernhardt submitted a new PF Insights post Getting Started with Solar System Imaging Continue reading the Original PF Insights Post.

Hi everyone This thread is for showing your images of solar activity taken with YOUR cameras, telescopes etc. That is, don't post images from SDO, SOHO or any other professional sources unless you specifically want to ask "how do they do that and what are those solar features I can see? This...

I am not sure if this is the best place to ask and I will change locations if need be, but I need some guidance on how to choose a proper sensor for my project. I am currently working as part of a team on a polarimetric camera for ocean imaging. The basic premise is that images, from above the...

Dear friends I am new at this forum thank you for accepting my application first of all. My question is that I don't understand the optics/physics behind the reason why Si-based CCDs are not sensitive for IR-light (above 1000-1100 nm) if on the top of the p-type Si there is a SiO2 layer which...

Usually the imaging through lens is described using geometrical optics or wave optics. However, I wish to study some imaging processes through lens where the light intensity is at the single photon level, under which condition I think the correct description should use a quantized...

Can anyone explain the basic principal of VMI? If it is possible then please give some study material links with your reply.

I have an image with uneven contrast. Now to correct the image, I need a dark frame to remove the noise inherent to the sensor or to the camera itself. How can use the dark frame into the image? I have been searching the net but most of them use photoshop or similar softwares. How can I apply it...

Consider an upright cylindrical concave mirror with a point source located at the focal point of the mirror. By upright I mean that the mirror is plane in the vertical direction and a concavity in the horizontal plane. Now it seems likely that you would see a virtual image of the point source...

Suppose I want to learn about MRI. Some of the introductory treatments I have seen aimed at engineers or imaging professionals may not assume much more than sophomore level physics competency. I know some advanced QM and statistical physics so I am wondering about the existence or value of a...

I'm a senior physics major, and I'm starting to look at graduate programs, and I'm very much interested in imaging as this is what I've been doing for the last 2 years. I'm really interested in medical imaging, but my concern is saturation in the field of medical physics. Would pursuing a...

hi guys Today I would like to show the advantages of stacking a set of exposures over just a single shot There are various ways to stack individual exposures. A number of programs are available ranging from free to quite expensive ... several 100 US$ free = DSS - Deep Sky Stacker...

Hi guys I want to know if it is possible to construct a multi-spectral imaging device inexpensively as a vein finder. what would be involved? There is a med device that has augmented reality to it and has a lot of other functionality but i think it costs about 10-15k. My budget is about $1000...

Hi, I am a novice at MATLAB and just started using it. I need some help with it. I want to post process an array of time domain signals using a specific algorithm. These time domain signals are acquired using labview and I want to post process them using matlab. I have the equation for post...

Unfortunatley I cannot post this question in the Homework section (not sure why) so I hope its OK if I post here and show work as appropriate < Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >[/color] QUESTRION State two design features in an...

Homework Statement (1) An ideal digital detector only suffers from quantum noise. If, after being exposed to 5 µGy the mean pixel value in the image is 100 and the standard deviation of the pixel values in the image is 5, calculate the SNR? The relationship between pixel value and detector...

Hi, my lecturer said that in PET imaging, the image resolution is superior when the E(max) of the positrons is lower. Why should this be? Thanks

Hello, I just was looking for possible information in the field of imaging quality assurance. I was wondering if their were any predominant scripts or papers on the subject of detecting the quality of an image. I know measuring how "good" an image is incredibly qualitative however, there are...