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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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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26 views
The change of focal distance as a result of adding a substance
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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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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37 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 ...
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31 views
How I can add lenses stacked on front of iphone camera to increase magnifying power?
How we can stack different lenses to increase magnifiying power of a smartphone camera? Is there any way to test if stacked lenses will focus light on image sensor of smartphone exactly right before ...
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CalTech has actually filmed light crossing a space of 1 mm of space. How?
In the video https://www.youtube.com/watch?v=7Ys_yKGNFRQ, CalTech has a camera capable of filming the picoseconds it takes for light to travel 1mm in distance.
It can do 10 Trillion frames per second....
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A Cheap Way for Seeing 1000nm to 1600nm Light
I have started a project in infrared where the spectrum covers 1000nm to 1600nm. A silicon based image sensors can see up to about 1000nm, while an iPhone attached FLIR camera can see from 8 – 14 µm, ...
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How can I determine the optics needed for a desk microscope?
As an noob to microscopy, photography, and optics in general, I'm trying to figure out if I can use the KPPACE KP-2100 camera as a desk electronics microscope. I want something I can mount to the ...
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1answer
58 views
Determining lens and sensor distance for narrow focus
I have the following items:
a round target object, approx. 6mm in diameter
a lens, focal length 20mm, F/2.8
a camera sensor, optical size 1/4" (note: I know this camera has a fixed-at-infinity lens, ...
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1answer
28 views
Would Camera Obscura work in low light conditions?
If I were to attempt to create a camera obscura affect in order to capture an image of the stars, or an aurora, would I still be able to get a decent one despite the relatively lower lighting ...
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1answer
50 views
Unable to get interference from milk using Time domain OCT (Michelson Morley interferometer) approach
I was able to construct time domain Optical coherence tomography based on Michelson Morley interferometer using a LED. While testing the interferometer, I used glass slide, layers of scotch tape. I ...
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How to add protective enclosure around exposed thermal camera
First off, let me state that I'm not entirely sure this is the right forum for this question. This was the only section I found multiple questions pertaining to thermal imaging, however, so I thought ...
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How to calculate minimum optical power required from datasheet of camera sensor?
How can I determine from the datasheet of a camera sensor the minimum optical power required to see a spot on the image?
I have 2 lasers with a diameter of 0.35 mm with respectively a power of 12nW/...
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How can I correct a projector's magnification with a simple lens?
I am struggling with a real-life optics problem. At work, I have a projector that makes an image too big for the screen. I think I can reduce the image to the required size by mounting a simple lens ...
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1answer
21 views
How loud does a sound need to be to make pressure waves detectable by a camera?
I've seen Veritasium's video that describes how sound can be picked up by a camera by observing small movements of objects sensitive to pressure changes (bag of chips, aluminium foil, paper...).
That ...
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312 views
How does the diaphragm in a camera work?
I think I am quite good at math and understand basic geometry, but I have problems understanding the function of a diaphragm in cameras.
Let's say a camera is in a specific state. It captures the ...
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2answers
65 views
How can I focus an optical device at infinity, inside a room with limited space?
I have a custom coupled camera/spectrograph imaging system that I need to focus at infinity for a microscope setup. I can't move the device outside, where I would be able to use some distant object to ...
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1answer
42 views
Optics of an all-sky camera
I'm curious about the optics of an all sky camera like this one or this one. My suspicion is that the sensor has an inherently wide field of view - the former has a lens that's 1.55, which doesn't ...
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Calculating required amount of lumen for camera sensor satuation
I am stuck on this problem at work - I hope some of you can help me further.
I work with underwater vision and am trying to find way or methodology to get a somewhat estimate of the required light ...
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1answer
48 views
Are These Guitar Strings Demonstrating Subharmonics?
This video has a fair few instances where there is an exaggerated wiggling of the guitar strings. I rationalise this by saying its a similar effect to rotoscoping, like where wheels appear to spin ...
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Strange optical distortion in a video recorded from an airplane window
I recorded this video from an airplane window while it was decreasing its elevation. What is the explanation for this optical distortion? This distortion appeared only in a certain range of elevation. ...
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1answer
23 views
Photomulitplyer Tubes and NaI(TI) crystals in Gamma Camera, Energy and spatial resolution
I am trying to understand how the PM tubes and NaI(TI) crystals are used for the energy and spatial resolution.
I understand the principle behind how the crystals and PMT work, but very confused to ...
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21 views
Can a controlled lighting environment be a substitute for bandpass light filters?
Could illuminating a subject with different LEDs be used instead of bandpass filters?
I am experimenting with capturing surface reflectance using a monochrome camera. The traditional approach to ...
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Calculating light level radiating back to camera from rough surface
Problem statement: I have an imaging sensor (“camera”) that has a minimal response specified at 1000 lux. This camera is set up to resolve a rough surface at 1 meter distance. Alongside the camera is ...
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1answer
36 views
Solving for $x$ and $y$ image coordinate given a 3D point
I have a 3D point, $(X, Y ,Z)$ and I want to know where it's imaged, $(u, v)$. I'm assuming a pinhole camera model with no lens distortion. I have the distance from the pinhole to the object ($z$), as ...
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How do I calculate the geometric dimensions of the following objects, given the image co-ordinates, and camera information?
I've zero knowledge in optics, but I've to estimate the geometric dimensions of objects from the values of the number of pixels and the camera information given here: https://www.raspberrypi.org/...
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Why doesn't projected image fill all my camera view?
so lets say i take a small lcd, and stick a lens in front of it. a magnified image will be projected on a wall. now lets remove this wall and stick a camera a little behind where the image is formed (...
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Why is the focal length of a camera inextricably linked to a different perspective?
The human eye can focus on different distances without ever changing the perspective. Why is the change of focal length in a camera, on the other hand, always linked to a change in perspective? Is the ...
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4answers
368 views
Focal Length Definition in a Camera
I am having trouble understanding the meaning of focal length. I thought focal length was the distance between the lens and image sensor. These sources validate that definition:
http://ksimek.github....
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2answers
105 views
Why can my camera see the Sun when I can't?
There was a lot of smoke blowing high over the west coast of the United States last summer due to forest fires. It was thick enough that near the horizon, the Sun was all but invisible. It could ...
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1answer
67 views
2 lens microscope with an iphone camera. Where should the imaging plane be?
I am trying to design a 2 lens microscope that can be attached to an iphone camera in Zemax. To optimize the point spread function I need to define an imaging plane at which it should be optimized. ...
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1answer
36 views
Remove lens distorsion with intrinsic or extrinsic parameters?
I'm struggling with the theoretics of camera calibration. There are the intrinsic parameters and the ...
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66 views
What are the difficulties of constructing a camera with $3.10^{8}$FPS? [closed]
what are the difficulties of constructing a camera with $3.10^{8}$ frames per second (FPS)? In order to study the nature and speed of light, can we construct a camera with $3.10^{8}$ FPS?
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Cameras in Voyager probes 2017 [closed]
Riffing off an old thread...
Analog v digital and data transmission aside, I'm wondering how images were captured in such low light at 37,000+mph. Seems like a wide open aperture and slow shutter ...
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Viewing totality though an unfiltered telescope [closed]
DISCLAIMER: This question is for informational purposes only and the ensuing discussion must not be construed as safety advice.
There seems to be a consensus among experts that partial eclipse should ...
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Lens equivalent depth of field
In digital photography, there's the principle of lens equivalency, according to which, when you shoot with a camera which has a smaller sensor than a full frame sensor (which is the same dimension as ...
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3answers
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Why can a regular infrared camera not show temperature (thermography)?
There are a lot of questions here dealing with infrared cameras and thermographic cameras. I think I understand the reason why a thermographic camera is able to retrieve the temperature values from ...
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177 views
Filter for RGB separation
Looking at Bayer filter of a typical consumer camera, one can easily see that sensitivity of the filter for each color is all over the place. Are there filters similar to Bayer that do a better job at ...
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176 views
Will the image of a pinhole camera be shifted if the light source is shifted as well?
If the angle of incidence ray is = to the angle of reflection. Then if the light source is shifted won't the image change too?
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Could aliens observe Curiosity, the rover?
Inspired by:
The color image, taken from a distance of 169 miles, is the combined view of three wavelength bands — red, blue-green and infrared.
Curiosity is not the only Earth visitor that ...
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Matching light flicker rate with camera's FPS
I know you can make water flow backward or make plants seem alive by changing the frame rate per second(FPS) of a camera. But what would happen if the camera took a video in an environment where the ...
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1answer
793 views
How to calculate the size of object in pixels, knowing the camera properties?
I'm trying to calculate the size of an object in pixels in an image, when I have these information:
...
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1answer
123 views
Nonlinear Response of CCD camera
What is meant when it is said a CCD's response is nonlinear? Does it mean the value of a pixel of the camera is not proportional to the number of received photons? Does it involve saturation? What ...
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2answers
2k views
Why a circular camera lens captures rectangular pictures
I want to know how a circular camera lens captures a rectangular picture.
Moreover what will happen if the lens was rectangular.
I have tried a lot to think about it but i could not figure out ...
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Photographing the night sky - How important is fixed alignment of the camera?
If I set up my long exposure camera on a tripod and point it at the sky at night with the pole star in the centre we get a lovely image of concentric circles or arcs of circles depending on exposure ...
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5answers
16k views
Why doesn't Earth appear smudgy or blurred in space photographs due to its fast rotation?
Whenever we take a photograph of something moving at a considerably high speed, its image appears fuzzy/smudgy/distorted due to motion blur. Why doesn't this happen in case of Earth photographs from ...
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4answers
422 views
Does a camera have single slit interference?
Because a camera has an aperture, I would think that there is single slit interference?
Does a camera have mechanisms to account for that?
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1answer
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What causes the Sun to appear to be in front of a building in this picture?
I took this photograph a few days ago, during sunrise, using my smartphone camera and digital zoom:
It seems that the sun is in front of the building. How is this explained?
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Is there any advantage in stacking multiple images vs a single long exposure?
Suppose I have a source object that is not time varying, to be concrete let's say it's a galaxy. Is there anything additional that can be learned or done with multiple short exposure images of exactly ...
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Does Bayer demosaicing from RGB-filter sensors work *because* the color filters are imprecise?
I have an ongoing friendly dispute with another member over on Photo Stack Exchange about the fundamentals of how RAW works, and I'm hoping you can settle it.
My understanding is that Bayer ...
