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.
162
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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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11 views
Can I able to detect (by long exposure shot) infra red region when black body is heated to its necessary temperature
When we heat a body ,it emits radiation in full spectrum with maximum spectral density at a particular wavelength depending on its temperature. When I heat the body to particular temperature , ...
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0answers
19 views
How to measure physical luminance just with regular camera? [closed]
Maybe there is some software for that task? Theoretically, it's able to realize. I guess it's may work somehow like bracketing in photography (making HDR shots from several shots with different ...
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0answers
15 views
Spatial Resolution and pixel smear and camera devices
Can anyone recommend a good source (video, textbook, online course) that I can use to learn more about spatial frequency, exposure, pixel smear, how cameras work. I only have some basic optical ...
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2answers
63 views
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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3answers
102 views
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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2answers
82 views
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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34 views
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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1answer
52 views
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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1answer
77 views
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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0answers
20 views
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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2answers
49 views
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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1answer
79 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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1answer
53 views
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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1answer
27 views
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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1answer
57 views
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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1answer
46 views
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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1answer
36 views
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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1answer
83 views
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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12answers
5k views
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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3answers
107 views
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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0answers
7 views
Estimate off axis source light loss with lens?
Issue:
I'm trying to measure some light sources very accurately. I'm finding an issue with light detected by the camera falls off as you move off the axis of the lens. Our objects are not ideal point ...
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0answers
23 views
Optical power collected by a detector coming from a Lambertian disk object in an active illuminated camera
I would like to estimate reduction of optical power in an active illuminated camera when a flat lambertian target is moved away from the camera. Below is formal description of the problem, I’m just ...
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0answers
21 views
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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2answers
52 views
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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1answer
44 views
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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0answers
22 views
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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1answer
77 views
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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1answer
120 views
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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0answers
76 views
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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3answers
129 views
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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1answer
37 views
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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1answer
35 views
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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1answer
56 views
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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0answers
24 views
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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2answers
373 views
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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0answers
27 views
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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0answers
28 views
Understanding atmospheric transmission's effect on IR camera [closed]
I'm using an IR camera to view a person at 1 meter, and then 5 meters. When I view them at 5 meters the max temperature I see for them drops by about 1 degree Fahrenheit. I assume this is because the ...
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2answers
678 views
Difference Between Angular Resolution and Spatial Resolution of optical device (Camera)
As per wikipedia angular resolution is the ability of device to capture minute details of an object and is the same definition in case of spatial resolution.
Whats the difference Between Angular ...
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5answers
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Why does a pinhole create an image of the Sun?
When I was a kid I happened to encounter a solar eclipse. I was taught that I should not look at the Sun directly when it is undergoing an eclipse, but I was extremely curious to see it.
Somebody ...
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1answer
58 views
Flicking a ruler (Camera optics)
A while ago I found this post on reddit which showed a ruler vibrating differently depending on the light: https://www.reddit.com/r/blackmagicfuckery/comments/ccymjq/...
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1answer
1k views
What is the white spot in the sky in this phone-camera photograph?
Consider the image below, taken with a phone camera. There is a white spot near to the Sun, which is dependent on the orientation of the phone. I know it is not a planet nor some sort of star but it ...
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1answer
90 views
Astigmatism and focusing a camera
A thought experiment: assume I have poor eyesight, but using a viewfinder or an LCD screen I was able to focus a camera on an object or landscape with what seemed to me perfect clarity. I took the ...
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0answers
85 views
Finding exposure time of a satellite camera
Note: I am not sure if this is the correct stack for this question
I'm working on a cubesat project, specifically on the camera payload. I've been tasked to find the exposure time of a VIIRS ...
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1answer
173 views
What are the objects that are like a crescent and blue sphere? (while taking shots of a solar eclipse)
This is the picture I have took while the solar eclipse. What are the objects that are like a crescent and blue sphere? I know that such (rays) appear whenever we photograph the Sun but what is the ...
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1answer
42 views
Why is the room converted into a camera?
Our physics teacher turns off the lights and has a tiny square of light open through the window, everything else being completely dark. There is a parking lot outside of our class and she is holding a ...
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1answer
79 views
Basics of camera calibration
I tried to find some useful explanation about camera calibration and stereo camera setup in the web but was completely overwhelmed by the hairiness of the content: but seriously though, does it have ...
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1answer
33 views
The change of focal distance as a result of adding a substance [closed]
I have a given focal distance between lens and an image sensor (in air). Now I add a protective glass with a known refractive index and width between the lens and the sensor. How can I calculate the ...
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1answer
44 views
Unique optical map of a uniform metal object
Given a metal object (let us say a perfect planner uniform surface) that has been exposed to external environment factors such as sun, wind, rain and others for couple of years.
This object has been ...
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1answer
78 views
Calculate dark noise in CCD given a pixel's counts for two exposures
Suppose I took two pictures with the same CCD camera in totally dark room.
The first picture was exposed for 1 microsecond, and the pixel given was 20 scales of grey.
The second picture was exposed ...
