Camera Definition and 27 Discussions

A camera is an optical instrument that captures a visual image. At their most basic, cameras are sealed boxes (the camera body) with a small hole (the aperture) that allows light in to capture an image on a light-sensitive surface (usually photographic film or a digital sensor). Cameras have various mechanisms to control how the light falls onto the light-sensitive surface. Lenses focus the light entering the camera, the size of the aperture can be widened or narrowed to let more or less light into the camera, and a shutter mechanism determines the amount of time the photo-sensitive surface is exposed to the light.
The still image camera is the main instrument in the art of photography and captured images may be reproduced later as a part of the process of photography, digital imaging, photographic printing. The similar artistic fields in the moving image camera domain are film, videography, and cinematography.
The word camera comes from camera obscura, which means "dark chamber" and is the Latin name of the original device for projecting an image of external reality onto a flat surface. The modern photographic camera evolved from the camera obscura. The functioning of the camera is very similar to the functioning of the human eye. The first permanent photograph was made in 1825 by Joseph Nicéphore Niépce.

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  1. N

    I Lens angle of coverage/image circle

    Hello, I was wondering what parameters determine the angle of coverage/size of the image circle of a lens. For example, for a fixed focal length, aperture and flange focal distance of a camera, what can a lens designer do to change the size of the image circle. I'd also like to know how the...
  2. Citronnier

    Film Advance system research for DIY Camera

    Dear All, I'm a french professional photographer working on Still Life and Architecture. As a long time and personnal project I'm working on a 3D printed/Laser cut analog camera that will shoot 6x4.5 frames. In the end it will be some kind of rangefinder with integrated electronic light...
  3. E

    Camera focusing motion: can you solve this math?

    This problem arose in modeling camera focusing movement, such as a control system might do. It assumes a simple (thin) lens, rays close to the optical axis, and monochromatic light. While most camera lenses are not simple, this is a first approximation. Camera lenses project an image of a...
  4. S

    A Focal length and focus point

    First of all, Let me present some of the things I found from research. (considering convex lens) Interpretation 1 => Focal length is the distance from the center of the lens to the point where all rays converge. Interpretation2 => Focal length is the distance from the point of convergence to...
  5. pairofstrings

    Digital Transparent Glass; what's its name?

    Hi. I need to know the name of the transparent glass which can display objects like Line, Circle, Numbers, or maybe my name. Thanks!
  6. C

    I What causes disturbance on my phone camera?

    Hi I have a cheap smart phone with a low quality camera when I go to take a picture there is what I would describe as like old television static appearing in front of the image as it appears on the phone screen (although what is beyond it can still be seen). I am wondering if this is just dust...
  7. V

    Optical geometry of smartphone camera.

    I posted the following on a phone forum and got no replies, as expected. It's a bit out-of-the-way and technical. Thought this might be a better place since the question still interests me. I'm using my phone to take photos of assembly procedures on my electronics workbench. However, the focus...
  8. A

    Unknown light-based Phenomenon

    Can you help me figure out how this light-based phenomenon works? Please explain with an intuitive answer using the simplest principles possible. Note how the location and width of the dark horizontal bands is constant with respect to the edge of the video frame. The LED light looks normal...
  9. T

    I Quantum entangled image sensor for space camera-telescope

    Could this be a possibility at some point? Since entanglement is not affected by distance, could we send cameras out to extremely distant places and get instantaneous signals? Only the image sensor would have to be entangled. It would still take the same amount of time as usual to get the camera...
  10. G

    Lens engineering for virtual reality

    What type of lens/prism would be needed to allow a image sensor to see 180 degrees, so the sensor could see a hemisphere. It doesn't matter if the input is distorted. I thought that a glass pyramid with a square base might work.
  11. J

    How to determine the range of sensitivity for a camera sensor?

    I am not sure if this is the best place to ask and I will change locations if need be, but I need some guidance on how to choose a proper sensor for my project. I am currently working as part of a team on a polarimetric camera for ocean imaging. The basic premise is that images, from above the...
  12. Sneaky6666

    How to create a camera mount with basic materials?

    I have a project which requires me to get 5 very specific images of an object from various angles. The user can't use their hands because it would be too shakey and introduce error. These images have to be precise and steady. So that's why I need to build a helper camera mounting device to help...
  13. O

    I 1 trillion frames per second

    First I am not sure if this is the correct place to post this thread, but the thread will be about optics, quantum physics and special relativity, so it is a mixed subject. Please watch this video first: This technology allows capturing videos at mind blowing 1 trillion fps, which allows us...
  14. Angela Ituriaga

    Space Camera Project

    Hey everyone, So, my school club was approached by a local entrepreneur that sends up cubesats as well as ping-pong ball sized "satellites." The original intent of these (what he likes to call) Pongsats was to get kids excited about STEM and space. He send them up for free via weather balloon...
  15. hackhard

    Tweet photos with Arduino Uno

    i ve got an Arduino Uno R3 and the OV7670 camera module SD Module and a Wifi shield . ive done tweeting with arduino using twitter library i was wondering Is there any library to post images in a tweet? or some other hack?
  16. Tareq Naushad

    How mirror/camera/tv work without human eye like system?

    Mirror/camera/TV etc. don't have a complex visual cortex system/perception like our eyes. Human eyes use rod,cone,neuron and above all perception of brain to make image. How come these devices create the same clear images/scenes at their surfaces by themselves without having the advance...
  17. C

    Camera which measures distance?

    Hi all, I'm having trouble finding something online which isn't a very complicated device, but I don't know if it has a specific name, which would help me in a google search. I have a motor in an MBE which moves the sample, and I need a camera which can read to a computer what the distance is...
  18. R

    Near Point Distance of 25cm, how far should object be?

    Homework Statement A magnifier has a magnification of 9× How far from the lens should an object be held so that its image is seen at the near-point distance of 25 cm? Assume that your eye is immediately behind the lens. Express your answer to two significant figures and include the...
  19. R

    What is the speed of sprinter running away from lens?

    Firsts of this is not my problem I don't even take physics but it is my girlfriends. She doesn't know how to get the answer an neither do I. I took some physics but not enough for this. 1. Homework Statement A sports photographer has a 160-mm-focal-length lens on his camera. The photographer...
  20. stalin

    Why shadows become dark when light intensity increases?

    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. Now, I switched ON a torch and pointed it to a stuff toy which was kept in front of a wall and a shadow...
  21. Serhatee

    How can I deactivate the shutter button?

    Hey guys, as a freshman, I want to deactivate this shutter button. I don't know how it works and its structure. I want to be able to connect two cables so that by giving current, I can take a photo. Which terminals should I use? Or different ways...
  22. GiantSheeps

    Stargazing Remote Controlling Truss Dobsonian Telescope?

    Is it possible to rig a Truss Dobsonian telescope like this one so that you can control it remotely from inside of a building while the telescope itself is on the roof of the building? Then is it possible to attach some sort of adapter to the telescope that would allow you to hook up a camera...
  23. D

    When I record a video of a projector screen, why are there black lines moving across the screen?

    from a bit of googling, i realize it's because the frame rate of the camera and the projector are different. however, i have tried recording videos with cameras of 60fps, 30fps and 15fps, and the projector is likely 60 fps. That's why I'm curious about this - which frame rate is faster (the...
  24. F

    Finding lens diameter - German physics task

    Hey everybody, I'm right now trying to solve a question I found in a German physics competition 2006 concerning the diameter of a thin camera lens. I'm not able to find a solution, since there is basically nothing given. Here the task (I underlined phrases which might be important): A ruler...
  25. A

    Emitting vs. Reflecting

    Hello, I was wondering how one would be able to tell the difference between an object emitting a certain wavelength of the EM spectrum, vs. an object reflecting that same wavelength of the EM spectrum. For example: 1) Suppose I have an IR source at 7 microns. I point this source at water, and...
  26. B

    Lens diameter calculation

    Homework Statement How we can determine The diameter of the lens of the camera approximitly that this picture took with that? ( we know that lens of the camera made by some parts but we count them as a thin one in Practical calculations ) Homework Equations m = q / p 1/f = 1/q + 1/p f =...
  27. W

    Lens's Diameter

    Hello guys, I was wondering if you could guess or even calculate the diameter of a camera lens with a picture of a ruler.