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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6
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1answer
590 views

How is a CCD able to collect images in drastically different lighting conditions?

I have read the basics of how a digital camera works. As much as I have understood, the digital cameras have a device called a CCD on which photons coming from the lens are incident. The CCD then ...
0
votes
1answer
19 views

Bayer filter mosaic [closed]

Hello, How a yellow or any other color that is not rgb light, get throw the Bayer filter since only allows the RGB value to pass ?
0
votes
0answers
23 views

Is it possible to create a magnetic field camera that resolves magnetic fields to their source?

Is is possible to build a camera that is composed of an array of compasses that can resolve its magnetic field readings to sources outside of the sensor similar to the way an optic camera creates ...
-2
votes
1answer
72 views

How do you detect the colors of a traffic light? (exam question) [closed]

I just took an exam where the question was: give three ways you can detect the colors of a traffic light given only a gray scale camera. You're allowed to use any optical devices. We learned about ...
-1
votes
1answer
37 views

Which gives the most realistic pictures, Mirror, camera or their combination?

By googling, I have found several different opinions about how to take one's own facial images more realistically: Some said photos taken by cameras (smartphone's cameras, if specific) are more ...
1
vote
1answer
105 views

why shadows become dark when light intensity increases? [closed]

I observed following phenomena today: in my room with some lightings, there is a stuff toy placed in front of a wall. The ambient lighting doesn't cause any shadow on the wall currently. Scene 1: ...
0
votes
1answer
41 views

Does 'focal length' mean something different with lenses and pinhole cameras?

Sometimes different but related things have the same name by some tradition or accident, causing a lot of headache to newcomers to a field. I would like to come to clear terms with this: does the ...
0
votes
0answers
19 views

What mega pixel are human eyes? [duplicate]

I always wonder with cameras improving still what I see from eye can almost never come close to that of camera particularly in low light. So what is the mega pixel resolution of human eyes?
0
votes
0answers
27 views

What are the physics principles behind “amphibious” camera lens windows?

Underwater camera housings have a window through which the lens looks. When the camera surfaces, a couple of things can happen, and I've seen both captured in the camera footage. In one case, water ...
0
votes
1answer
84 views

Would a camera that only takes light at 90 degrees work?

From what I understand cameras and biological eyes work in a similar fashion, they all take light in a cone and distances are perceived as the angle which the object takes up rather than it's physical ...
1
vote
1answer
37 views

What sizes are detectable from 1m using a fairly good cmos camera?

I haven't ordered a CMOS camera module yet, but I am planning to use it to detect a small object from ~1-1.5 meters. Just too be specific, say I am using the following CMOS camera (although if you ...
0
votes
0answers
18 views

Interferences while using two ToF cameras

Im using two time-of-flight (ToF) cameras, a DS325 from SoftKinetic and a Creative Senz3D, at the same time with the DepthSense-SDK and the Point-Cloud-Library (on Ubuntu 15.04). But I got strong ...
17
votes
1answer
1k views

Land proportions in NASA blue marble photographs

What is the explanation for the apparent size difference of North America in these two photos from NASA? Image source Image source
4
votes
1answer
66 views

How to obtain initial conditions to image Kerr black hole?

I'm reading Gravitational Lensing by Spinning Black Holes in Astrophysics, and in the Movie Interstellar to make a raytracer code to image Kerr black holes. The paper introduces a Fiducial Observer ...
28
votes
3answers
6k views

Why are there no stars visible in this photograph?

Pluto and Charon, photo taken by New Horizons on July 8, 2015 from a distance of 6 gigameters. it's hard for me to believe there were no stars behind the twin dwarf planets in the field of vision. ...
2
votes
0answers
29 views

Searching for a textbook on Imaging

I'm hoping someone can recommend a book that will cover the physics involved in optical range image capture. I have a degree in physics, so I am looking for something on the technical end. To expand, ...
0
votes
1answer
130 views

How to calculate the diameter of a thin lense?

A photo produced with a single thin lense is provided. Only based on the photo I should calculate the diameter of the lense. The photo shows a ruler in the foreground and a point source of light in ...
4
votes
3answers
298 views

Why does shining a laser into an iPhone camera create these shapes?

When I shine a laser light into an iPhone 6 camera I get these weird shapes: The shapes are in no way in the background behind the laser. What causes these to appear? I know about typical lense ...
1
vote
2answers
131 views

Is it possible to calculate the dimensions of ANY object in a picture having at some known distance an object on know dimensions?

Is it possible to calculate the dimensions of ANY object in a picture having at some known distance an object on know dimensions? I'm thinking about the scenario where someone is holding a smartphone ...
0
votes
2answers
109 views

Video of light passing through water

How is this possible? https://www.youtube.com/watch?v=EtsXgODHMWk Video shows beam of light travelling through water. I was under impression that Einstein's equations showed that light speed is ...
0
votes
1answer
122 views

Size of object from its image [duplicate]

If the quality of the camera (i.e. the megapixels) (assume to be $x$) of the camera is known and an object is kept a known distance from the camera (assume to be $d$), can the actual width and length ...
0
votes
1answer
111 views

What is the visible spectrum to common mobile phone cameras? [closed]

With my iPhone I can see the IR emitter on a tv remote, which could be around 940nm, but I thought cameras generally tried to filter for the human visible spectrum (i.e. sub 700nm). I'm trying an ...
3
votes
1answer
152 views

Can I catch a single photon with webcam's CMOS or CCD sensors?

I thought it would be nice to capturing single photons using a webcam's sensor due to simplicity. I've read that ccd and cmos sensors have a certain percent of quantum efficiency. What about ...
1
vote
1answer
127 views

How to extract depth of a pixel from an image?

I'll have a few pictures that show the same scene, but only a few things move around a little bit. Now I don't have an information about any size in real life but I'd like to extract a scaling factor ...
2
votes
1answer
30 views

Common CCDs and photons

Is it possible to capture single (refracted?) photons with a CCD in a typical digital camera? Are these more likely due to coatings, etc? I have minimal knowledge of physics, but am curious.
1
vote
0answers
41 views

Constant part of a photo taken [closed]

(56th Polish Olympiad in Physics, II stage) A photographer has a camera with a lens of focal $f$ with can be set to a value from the interval $[f_{min}, f_{max}]$. The diameter of the diaphragm is ...
23
votes
7answers
6k views

Is there a maximum frames per second (FPS)?

Take a video camera and crank up the frames per second rate. Disregarding current technological advancements, could a camera's FPS go so fast that any two captured images be identical? Would ...
2
votes
3answers
2k views

What are ADU (analog-to-digital units)?

Can someone explain simply what are ADU's? I was reading this post here: http://www.qsimaging.com/blog/understanding-gain-on-a-ccd-camera/ However, I still don't quite understand this statement: ...
0
votes
1answer
94 views

Calculating distance between two objects viewed from an angle [closed]

I'm trying to determine the location of this vehicles rear bumper and the front edge of the white road marker. I can't tell if the vehicle is before, at the edge, or just ahead of the marker. The ...
0
votes
1answer
942 views

Are there any radiation emitted from the cameras? [closed]

Do modern video cameras emit any kind of radiation? If so, what range of frequencies they have? I was wondering if we can detect any radiation so any help regarding detection will also be appreciated. ...
-1
votes
5answers
341 views

Is there a limit to the frame rate achievable with a high-speed camera?

A high-speed camera is a device used for recording fast- moving objects as a photographic image(s) onto a storage medium. A normal motion picture is filmed and played back at 24 frames per second, ...
2
votes
1answer
88 views

Increase contrast on the image taken by CCD camera

I project a pattern on a reflecting object and I capture the reflected pattern (reflected via the object) using a CCD camera. However, the reflected pattern has a very low contrast (due to volume ...
1
vote
1answer
480 views

Creating large aspheric lens profile for CNC cutting out of Acrylic plastic for huge Camera Obscura

I plan to use a CNC mill to cut a plano-convex aspheric lens from a large (300mm dia) thick(30mm) block of Acrylic (PMMA/Plexiglass). I need a focal length on the order of 800-2000mm The purpose of ...
3
votes
1answer
300 views

Help calculating field of view for ball lens I just bought

I have a 5 mm (diameter) solid ball lens that I intend to place in front of a 36mm X 24mm camera sensor (I have already made preparations for the image to be focused and for the sensor to not be ...
0
votes
2answers
154 views

How camera flash can send information

Nikon have CLS a system that allow to trigger one flash with other flash. I don't know how exactly it work from user point of view, I think that one flash (in command mode) can send information like ...
5
votes
0answers
98 views

Why does the video recorded by a falling, rotating camera seem to stabilize?

Here is a video of a GoPro falling from a plane: http://www.youtube.com/watch?v=QrxPuk0JefA Any idea what is happening when the image "stabilizes" around 0:35? I think it is because the camera's ...
0
votes
1answer
520 views

Why do people look different in a photo and in a mirror? [closed]

Edit: Why do people look different in a photo and in a mirror? What is more accurate of the two? P.S. I've edited this question and I suppose it is no longer opinion based.
2
votes
1answer
199 views

Thermographic camera vs infrared camera

AFAIK, all objects above 0K emit infrared radiation. It is an electromagnetic radiation, like visible light. I guess thermographic and infrared cameras work on the same principles, but their images ...
1
vote
2answers
465 views

How to test cutoff frequency of IR filter on camera?

Modern cell phones seems to come with IR filters on their cameras. I want to do an experiment to figure out what wavelengths these filters allow to pass and which they block. How would I go about ...
5
votes
2answers
484 views

Is there a limit to frames per second to be captured?

Today we see ~100,000 fps cameras for hyper slo-mo. Is there a physical limit for frames per second for a camera? Speed of light maybe? How?
0
votes
4answers
999 views

Blocking an IR camera [closed]

What kind of material would be best to block an IR camera? Would Silicon work? (e.g the Silicon typically used in iPhone cases) Rather than covering the object/subject, I'm interested in fully ...
2
votes
2answers
119 views

What is “field size” when referring to perspective?

I'm trying to get my head around perspective. If you look at the animation in Wikipedia : You can see that the cube looks very distorted, then the edges go more parallel. From my understanding, ...
1
vote
1answer
2k views

Calculate the distance between two points from iPhone Camera

I want to calculate the distance between two objects using an iPhone camera. Suppose I'm standing with my iPhone 10 feet away from the objects. Now, I want to calculate the distance between those ...
4
votes
1answer
160 views

Optics, lenses and our eyes

When we view an image, is the focal point of our eye on our retina? Shouldn't that hurt? Also, if that is how our eye works, then why don't lenses put the focal point their equivalent retina? I was ...
1
vote
2answers
239 views

Flashlights and Capacitors

Why capacitors are used in flashlights of cameras instead of attaching the light directly to the battery? How this leads more light?
1
vote
5answers
3k views

The rule breaker, emissivity + reflectivity = 1

If emissivity and reflectivity are inversely proportionate, why does glass have a high emissivity of around 0.95-0.97 as well as being very reflective for IR Radiation? normally it works but not with ...
9
votes
3answers
976 views

Put a sensor at the focal length, behind, or in front?

My intuition tell me that at the focal length a convex lens all the light converges to a point. Following that logic, it would make sense to me that a camera chip would either need to go slightly in ...
1
vote
0answers
58 views

Modeling the probability of a photodiode measuring photons targets at a neighbor

In current digital cameras, sensors are arrays of photodiodes which "transform" photons energy to electrons. I am aware that the probability of a photon to generate an electron is modeled by a Poisson ...
1
vote
0answers
171 views

Digital camera as a measurement device [closed]

It is know that digital camera is not the best device for quantitative measurements. However, it is often used in all sorts of atmospheric physics research, maily due to: Low cost and availability. ...
9
votes
2answers
3k views

Infrared remote flashes blue light in camera

I know that if you held an infrared remote in front of a digital camera, it'll flash a blue/purplish light when you press the buttons. Why? (Image by Zombie Rider.)