Questions tagged [camera]
A device used to record static or moving images, either digitally or on a physical medium. The images captured may be in any region of the electromagnetic spectrum such as x-ray, infrared, visible, or ultraviolet and beyond.
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Reflect visible light transmit infrared light
I have a color camera and PIR sensor inside a commercial security camera which records when motion is detected.
I want to hide the security camera behind a 1/2 inch polycarbonate window which reflects ...
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My phone sees the NIR from a TV remote. Why does it not see the NIR in rainbows?
My Pixel phone's camera shows the IR light from the LED of a TV remote as a magenta/lavender color. That wavelength is likely around 940 nm.
Now, when I take a picture of a rainbow in the sky, it does ...
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Can I use Gaussian Optics and Aberration Theory to find the direction of a ray from the sensor to the world?
I am working on a master thesis which is a continuation of a previous one, which can be found here, with a nice summary: https://twitter.com/dearlensform/status/1465776613094797319
The thesis is ...
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Effect of ambient fluid on a pinhole camera's intrinsic parameters
Suppose I am performing calibration of a pinhole camera under the Brown–Conrady distortion model and find the focal length $(f_x, f_y)$, principal point $(c_x, c_y)$, radial distortion coefficients $...
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How can a camera capture the movement of light (in slow motion) if the electronics operate below the speed of light?
A while back I saw the MIT produced video where they show their camera capturing 1-trillion frames per second and show the light moving around a coke bottle in slow motion.
https://www.youtube.com/...
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C-mount lens filter and focal length
I'm building an eye-tracking system for mice.
For that, I am using a monochrome camera that would capture Infrared Light out of an 850nm LED, and a zoom lens to refocus the image when needed.
I also ...
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What is the Point Spread Function of a pinhole camera?
Is the geometric spread of a pinhole camera a uniform blur convolution?
Pinhole cameras have blur due to a. wave effects (diffraction) and b. ray effects (geometric properties). This question ignores ...
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Why scratches/tape affixed on lenses don't appear in the images captured?
I read this article about dirt on lenses. https://photojottings.com/dirty-lens/
In this, the author puts a small tapes on the lens and we can still see the image. We don't see the tape anywhere in the ...
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Why does my glossy blue guitar reflect different color images on my phone, but reflects white from a gelled camera flash
I have a blue glossy guitar that I was trying to photograph for product photography practice.
I wanted to have a pink rim light on it, so I angled the flash appropriately and put a pink gel on it. ...
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How to reduce camera field of view (FOV)? [closed]
If I have a camera with a FOV of, say, 17⁰ deg, how can I limit that FOV to 1x1 deg? I imagine some sort of mask is what I am looking for, but what needs to be considered in designing a solution?
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How can I determine how much energy a sensor pixel can withstand before exploding? [closed]
I am trying to design a camera system to image a laser beam. I know the sensor is a Sony IMX226, and I have the data sheet for this sensor. The data sheet, however, does not list a maximum energy ...
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Strange behaviour of ultra dark image in a CMOS camera? [closed]
Samsung Galaxy S21 Plus has a CMOS camera.
I recorded an ultra dark raw (DNG format) image using its Pro mode in the following conditions:
ISO 50
Shutter speed 1/12000
Cover the aperture with ...
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Vertical peaks in single slit diffraction pattern
I have the output from a single slit diffraction experiment using a HeNe laser (632.8nm), the diffraction grating is placed vertically so you expect to see only horizontal diffraction peaks in the “...
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How to calculate Distance $D$ to object from a camera with known $H$?
I am using algorithm to draw a bounding box around object when they appear in camera as shown in attached image. The main confusion is that i consider the object closer to camera when the Distance $D$ ...
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Why does cooling down thermal imaging cameras increase sensitivity?
A lot of high-sensitivity thermal cameras and sensors are (cryogenically) cooled down to low temperatures to achieve these high sensitivities. For example. the Stinger missile, and the James Webb ...
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Is it possible to obtain noise level in electrons using only one camera?
In the link, https://www.photonstophotos.net/GeneralTopics/Sensors_&_Raw/Sensor_Analysis_Primer/Photon_Transfer_Curve.htm
there is one figured called Standard Photon Transfer Curve – Multiple ISOs ...
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Are there Wolter telescope lenses for consumer cameras?
Wolter telescopes are used for x-ray astronomy. However, I see no reason why they couldn't be used for visible light as well.
How would a visible image look when taken through a Wolter telescope?
Are ...
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Narrowness of black bars to be resolved by camera?
So the question is:
A digital camera has a lens with a focal length of 10 mm.
The image sensor, i.e. the photosensitive part of the
camera has 7.5 x 7.5 μm pixels. A test map with a variety
of ...
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Why doesn’t an irregular or polygon shaped hole work like a pinhole camera when held close to the screen?
When a card with a hole of any shape is held close to the screen, the lighted area on screen is of the same shape as the hole. To make an image of light source, say Sun, the card has to be moved away ...
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Cameras that can see through opaque objects
Are there cameras which can see through opaque objects (i.e. a reasonably dense curtain, cardboards or walls)?
And by see I mean in almost full color the way a regular camera would work.
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What if cameras get better than our eyes?
What happens when camera technology evolves so dramatically that (without considering zooming) camera lenses get “better” than our human eye?
Do we see the footage in higher definition, or do we ...
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How can a digital camera capture and render IR (and UV) light?
It is known that you can see IR with digital camera. I have personally tested with camera of phone and webcam with a RC of A/C. It is seen as mostly white light with red tint. I haven't tested with ...
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Weird pattern for a laser beam spot
I am trying to measure the gaussian profile of a laser beam, which is supposed to be T00. The profile shown in the specifications looks very Gaussian, and the laser is brand new. I am using this ...
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How our eye see real images formed by pinhole camera? [duplicate]
How do we(eye) see real image form in pinhole camera?
1.Are rays that are forming image pass through screen and reach our eye help us too see it ?
OR
Light rays from hole from where we are looking at ...
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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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Is it possible to use a distributed camera array to fake an interferometric sensor without phase data?
Astronomical interferometry is a technique which uses multiple small telescopes to mimic one giant telescope. It requires the phase of the light to be captured for it to work. It is widely used in ...
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Can there be multiple shot noise sources? For example: laser & camera
Suppose you have a system consisting of a laser, a filter (with transmission $T$), and a camera. To my understanding, both the laser and the detector produce shot noise. Is that correct?
For a camera ...
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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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Resolution of a Michelson Interferometer using a Webcam
I've built a Michelson interferometer which uses a webcam as screen. This setup shall measure and correct drifts in optical path difference of the two interferometer arms.
I have problems determining ...
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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 a thermal camera detect distant objects colder?
Thermal cameras are often calibrated and display the temperature color-coded in $^\circ$C and I wonder how that works...
A black body emits photons because of it's thermal energy. The hotter it is, ...
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Damage from the Sun on a Raspberry Pi Camera Sensor with a Fisheye Lens
I'm working on a CubeSat mission which uses two Raspberry Pi V2 cameras (without special filters) as sensors. I am trying to estimate if they could suffer thermal damage if they were to have the Sun ...
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Does the size of CCD/CMOS of a telescope affects the magnification?
For a normal, traditional telescope, the magnification level should equal to focal length divided by eyepiece diameter, i.e.,
$$Res=\frac{f}{D}$$
So does the size of the CCD/CMOS the same as eyepiece ...
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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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Why do images not appear inverted when looking directly through a pinhole camera?
I understand that the way light takes through a pinhole creates an inverted image on a surface behind the pinhole. I remember this effect from school experiments, it's also described in this wikipedia ...
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Relativistic-speed cameras [closed]
I am asking on behalf of someone else. Here is their question:
Two cameras, each recording video at 500 trillion fps, are speeding toward each other at $0.6c$, on a direct collision course. When the ...
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What is the right camera lens for imaging this experiment?
I am conducting an experiment in our lab where we are using an ICCD camera to image a very short-duration (ns) physical phenomenon. The area of interest of the test is about 25mm x 25mm and I need to ...
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Why is the geometric spread and dispersion spread in a pinhole camera independent?
About 6:08 of this video, the equation for geometric spread($ x_{geo}$) is derived for a pinhole camera:
$$ x_{geo} = \frac{d}{s} (f+s) = d(1+ M)$$
Where,
$f$ is focal length
$s$ is subject length
$d$ ...
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Technical name (radiometric/photometric/ray-optic) of the physical field that is measured with a camera
A camera (that is FPA and objective) is a device that measures [intensity][1] or radiant intensity vs. two angles (horizontal & vertical). So it generates a representation of the physical quantity
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Relating exposure time of a camera to number of photoelectrons
How can we relate the exposure time of a camera to the number of photoelectrons created on the detector? We know the power and the wavelength of light hitting on the camera, quantum efficiency of the ...
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Can a curtain create a focused image on an opposite wall?
This video* (linked at the correct time of 0:26 sec) shows a scene inside a room of a home. Apparently projected on the wall is an imperfect but recognizable image of the outside street scene. The ...
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Type of camera that is used in a double slit experiment [closed]
I need to know the type of camera that is used in a double slit experiment. Both with photons, and that with electrons? Can someone please answer. The type of camera that is used for observation. Is ...
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How do single-pixel cameras work?
To obtain images using a single-pixel camera we need a Digital Micromirror Device (DMD) because single-pixel cameras only possess a single detector (article).
From my understanding, a single-pixel ...
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If image formed by a plane mirror is virtual, then how are we able to capture that in a camera?
What I have learnt in school is that, we are able to see images behind a mirror(virtual image) because our brain assumes that the diverging rays that our eyes see, are coming from a point behind the ...
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Specular Reflection of IR Light
I have started to use thermal imaging cameras more and more and realized that I can see the reflection of my self bouncing off of a glass window through the IR camera. When viewing it on my monitor, I ...
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Pinhole camera as a device to develope photos of distant stars? [closed]
Could a transparent slab coated with photosensitive film be placed inside a pinhole camera nearly paralel to the path of the light emitted by a source of light(star) to produce a picture wich due to ...
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Vision: eyes vs cameras
I think this is related to physics, and light waves.
Is there some materials that can be seen by human eyes and can't be seen by cameras? (Imagine a special writing) Is that even possible therotically?...
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Why hyperbolic shapes of colour distortion in this image? [duplicate]
I took a photo of my computer screen through my mobile phone camera. Why are these color distortions in hyperbolic shape?
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Limits of zooming in (for camera/telescope)
What limits the ability of a camera/telescope to zoom in on distant objects?
The question is twofold:
What zoom really is?
Firstly, I would like to gain clear understanding of what we mean by zoom ...
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Estimating the focus plane of camera via thin lens equation [closed]
I have a camera that outputs a JSON file for every image taken. In the JSON file, I can find camera-specific and also the photo-specific acquisition parameters used. The issue is I wish to estimate ...
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