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2
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1answer
24 views

How can I simulate two fluorophores with a reticle?

Fluorophores typically emit in an incoherent fashion. I thought I could simulate two fluorophores (e.g. single molecule fluors) with a reticle. My concept was to make two small holes in a chrome ...
2
votes
1answer
34 views

CARS microscopy

I have probably very naive question. In case of CARS microscopy http://en.wikipedia.org/wiki/Coherent_anti-Stokes_Raman_spectroscopy we have $ω_{pr}+ω_{p}-ω_{S}$, how can we have minus $ω_S$? In ...
0
votes
1answer
70 views

How to perform a rotation of field of view using only mirrors/lenses?

How does one rotate a "microscope" fluorescence image on the detector using only lenses and mirrors in the set-up shown above? I am trying to do ray tracing to understand how to do this, but lenses ...
4
votes
0answers
33 views

Quantify shade-off and halo effect in phase contrast microscopy

Shade-off and halo effect introduce distortion to phase contrast images. I am trying to utilize these features to write a program which could identify spherical cells from (positive) phase contrast ...
4
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0answers
65 views

Selecting an epi-illuminated objective for optical microscopy

I am currently trying to improve my silicon microphotography. To provide context: this is what I get with a 10x epi plan objective¹: This is what I get with 40x epi plan objectve with NA=0.65: I ...
3
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0answers
208 views

Why do spatial filters use microscope objectives, and not other types of lenses?

A spatial filter is a device to 'clean up' a laser beam with an irregular intensity profile, and create a smooth Gaussian profile at the output. It is usually said (e.g. here) that you need a ...
3
votes
0answers
16 views

Resolution Limit for Energy Transition Imaging

I understand that when imaging the resolution limit can be given by Ewald's sphere which is due to the maximum amount of momentum that can be transferred. But how can we come up with a resolution ...
2
votes
0answers
86 views

What criterion did Abbe use?

For a microscope (correct me if I am wrong) the Rayleigh Criterion gives us: $$ R=\frac{1.22 \lambda}{NA_{condenser}+NA_{objective}}$$ But with the Abbe diffraction limit: $$ R=\frac{\lambda}{NA_{...
1
vote
0answers
28 views

Simulating a noisy image: Poisson Noise Clarification

I'm currently working to simulate an image that mirrors the output of a CMOS camera we have in the lab. My images include Poisson (photon) noise as well as a gaussian (readout) noise. My issue is ...
1
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0answers
51 views

How was microscope-level zoom created by a lens and a water droplet?

It was a rainy night. My glasses were speckled with fresh water droplets. I looked at a distant street light and I was surprised to see cells - a single cell was zoomed in to the level where I could ...
1
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0answers
48 views

A lot of high power microscopes have 2500x magnification, why that specific number?

I've been shopping around for a microscope, and I've noticed something I didn't really expect. Across different brands, across different times (look at some "vintage stuff"), many many microscopes ...
1
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0answers
25 views

How is the Rayleigh criterion connected to the Abbe limit

I am interrested whether one can derive a formula for the point resolution (like Abbe did) of an optical system from the Rayleigh criterion (without the use of small angle approximation i.e. $\rm{sin}(...
1
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0answers
22 views

influence of soft iron in magnetic lenses

I'm currently working as an intern in a research group which is specialized in transmission electron microscopes. I'm reading a book from David B. Williams and C. Barry Carter : Transmission electron ...
1
vote
0answers
95 views

Why isn't the magnifying power in a compound microscope zero when image is formed at infinity?

I think, in a compound microscope, angular magnification and lateral(or linear) magnification is given by the same formula for both image at infinity and near point(D) And the formula is $$M=m=m_om_e$...
1
vote
0answers
16 views

Could a Kelvin Probe Force Microscope, in principal, be used as a voltmeter?

This question goes into the very nature of the work function that the Kelvin Probe Force Microscope (KPFM) measures. https://en.wikipedia.org/wiki/Kelvin_probe_force_microscope Let's say, you have a ...
1
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0answers
23 views

Spherical Aberration Of Electron Lenses

I would like to know why electron lenses can't have negative spherical aberration. Every textbook I have found devotes one or two sentences to saying that Otto Scherzer prooved this 80 years ago, but ...
1
vote
0answers
74 views

Importance of thickness of SiO2-substrate for observing graphene's monolayer

I've discovered that one should use 300-nm-thick SiO2 substrate in order to effectively observe graphene's monolayer through optical microscope. If thickness differs even by 5%, i.e. 315 nm, then ...
1
vote
0answers
56 views

Microscopy: aperture matching and Huygen's principle

I have repeatedly read that the maximum spatial resolution of a microscope occurs when the aperture of the objective and condenser are the same. However, I don't understand why. The resolution is ...
0
votes
0answers
11 views

Relation between phase of dark field and bright field images

I am trying to understand how the super-resolution technique based on Fourier Ptychography 1. In the paper, we run phase retrieval algorithms using images captured using illumination at different ...
0
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0answers
21 views

How to get rid of optical reflections in microscopy?

I am running a Raman microscopy experiment with polished silicon wafers. Each time I make an optical image of the wafer surface, reflections appear to the left of the image. This is even worse for ...
0
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0answers
22 views

determine axial resolution in microscopy

I want to determine the axial resolution of a fluorescence microscope. As I understand, this is commonly done employing a thin fluorescent specimen and performing an axial scan. The axial resolution ...
0
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0answers
14 views

Microscopy - Depth of Field Shrinks with Magnification

From empirical results I was able to gather that the DOF of a microscope I was working with had been reduced, when I swapped the tube lens to a one with greater magnification (but the same objective ...
0
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0answers
8 views

what are the things that affect the ion mobility of a particular material?

what factors are important in ionic transition in a substance? please use easy word to answer as I am a high school student.
0
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0answers
29 views

Are the Rayleigh criterion and the Point Spread Function related to each other?

Reading this paper as of now, and at the very end of the appendices, it mentions that: However, assuming a highquality preparation, the limit of resolution for any application is always ...
0
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0answers
26 views

What are the figures of merit/ performance measurements I can use for deconvolution?

I'm currently performing deconvolution on a bunch of 2D slices of fluorescent beads using MATLAB. Now I want to measure the performance of different deconvolution methods on the filtering of the PSF(...
0
votes
0answers
27 views

How does one go about measuring the Point Spread Function pertaining to a particular microscope?

I am aware of the two ways in which to obtain the PSF: Theoretically and Empirically. I understand that empirically, you would have to use fluorescent beads. However, I am missing information as to ...
0
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0answers
31 views

Btter using a cheap RGB or Monochrome-LCD as a mask for an incoherent white light source compared to?

To be precise, I'm trying to implement ans adaptive condenser-aperture in a brightfield microscope. It's remote and I don't want to have it mechanical moving all the time when changing the objective ...
0
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0answers
50 views

Why the Kondo effect is important for STM?

The Kondo effect is observed when approaching 0K. Why would this effect be important for STM?
0
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0answers
34 views

Interaction with the Specimen in Electron Microscope

I read that Electron microscopes throws a high speed electron beam (in vacuum) on the specimen to create a magnified image of the specimen. I wish to know about the interaction of the electrons of the ...
0
votes
0answers
50 views

Why don't electron microscopes use huge detectors?

Electron microscopes have limited resolution. I have read experts saying that we need better electron detectors to get better resolution. Why can't we just use bigger detectors? Increase the ...
0
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0answers
44 views

Magnification: Microscopes Telescopes

What is the difference between the way a microscope magnifies say a star and a telescope say a cell? Why is it, that the eyepiece of a telescope magnifies stronger when it is smaller and with a ...