What is Camera: Definition and 304 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. D

    Can a highspeed camera show a laserbeam moving?

    Just wondering if we could make a high speed camera that shows a actually laser beam slowly moving across the room in front of the camera? Given its moving at c, is there a camera that can record fast enough to see it move at walking speed? Like slow mo vids of a bullet flying past the camera.
  2. N

    Can I Use a Disposable Camera Flash for Water Drop Photography?

    Ok so last year I went way over my head and tried to build this http://makezine.com/04/strobe/" . Which ended up being a huge failure, now I want to try doing something simpler. I went to CVS and they handed me 12 disposable camera's then which I figured out that if apply 5 volts to a pin and...
  3. Z

    Simple lens question (camera)

    Homework Statement Was wondering if someone could help... Homework Equations 1/f = 1/u + 1/v m = v/u The Attempt at a Solution Using: 1/f = 1/u + 1/v 1/50 = 1/8000 + 1/(v) v = 50.3 mm Then to calculate the linear magnification of the image, using m = v/u with same v and u...
  4. Z

    Simple Lens Diagram for a Camera

    Homework Statement A simple camera has a converging lens and the image is in focus on the screen. The paths of three rays from the tree to the lens are shown in the attached diagram. Complete these paths to show the formation of the image on the film.Homework Equations The Attempt at a...
  5. Z

    Question from simple lens diagram (camera)

    Homework Statement A simple camera has a converging lens of focal length 50.0 mm. It is used to photograph a tree 3.00 m high. The tree is 8.00 m away from the lens. Calculate the distance v between the lens and the film, giving your answer in mm to three significant figures...
  6. T

    Understanding Camera Zoom Lens Calculations

    Homework Statement A digital camera has a 3x zoom lens whose focal length can be varied between 6-18mm. The lens is assumed to be thin. The image is formed on a CCD sensor whose diameter is 10mm. 1. How large an object can be captured with the camera if the object is at distance of 10m from...
  7. B

    How do I determine a camera projection matrix?

    I'm an undergraduate computer-science student doing research in the field of computer vision, and one of the tasks I've been charged with is calibrating the camera on a robot. I understand the basic principles at work: a vector in 3D world coordinates is transformed into homogeneous 2-space...
  8. E

    Flash Camera Cell Phone Problem

    Hello, I have a Nokia 6300i cell phone with double flash camera. The camera's flash was just working fine in the begining, then in one day I tried to capture a photo in the night with flash turned to automatic and it did not work. Then, I turned the flash to be on all the time, but useless...
  9. G

    Solving Camera Lens Problem for Film Size of 24x36mm

    The actual frame size of "35-mm" film is 24 mm x 36 mm. You want to take a photograph of your friend, who is 1.70 m tall. Your camera has a 60.0 mm focal length lens. How far from the camera should your friend stand in order to produce a 36.0 mm-tall image on the film? i thought you would...
  10. O

    Filtering certain wavelengths from the camera RGB videostream

    Hello, We are using ordinary CCTV cameras to grab color pictures. The representation of the picture in our image processing application is in RGB format. Is it possible to determine wavelength of the light at particular pixel from RGB values ? The purpose is to cut out all the white light...
  11. A

    How far from camera person should stand?

    Homework Statement A 35 mm camera has a lens with a 50 mm focal length. It is used to photograph an object 175 cm in height, such that the image is 30 mm high. (a) How far from the camera should the person stand? Answer is The person should stand 297 cm away from the camera...
  12. W

    Can Breaking a Traffic Rule Change Your Life?

    I'm heart broken to announce that I have broke the law of the land. I made a premeditated red light turn on an intersection 6.4 seconds too early. Not 6.0 seconds but 6.4 seconds. I seek forgiveness for what I have done. I seek to confess my sins - yes everything. I promise to write "I will...
  13. R

    Do Camcorders/ Video camera have Sensors in them?

    Curious. I have a video camera and I've decided to take it apart. I posted a thread a while ago about building a robot, so It would be nice if somehow i could use something from this camera to give it "vision" or "Senses". So I want to know. Do these things have sensors in them? Is that how they...
  14. P

    How Is a Dark Frame Taken in CCD Cameras?

    Hello, I have two question regarding CCD camera technology. How is a dark frame(image) taken ? ( Is this simply the state of the pixel array when the shutter is in close position? How can one determine the camera efficiency as a function of energy from energy dependent measurements...
  15. Y

    Video camera links in Special Relativity

    There's a video camera at a railway station. It can see the driver in the front of a fast moving train going past in the distance. Another camera is on the train itself, again filming that driver. v= (whatever it is)? so that gamma = 3 The train's own camera is filming the driver making a...
  16. W

    What camera should I choose for my wife for Christmas?

    I am here hoping for some geeky advice on a camera for my wife for Christmas. The most important features are going to be speed (meaning "boot up time" and time to capture the image after pressing the button) and taking good pictures in lower light without her having to think a lot about...
  17. S

    Understanding Quaternion Multiplication for 3D FPS Camera: A Simplified Approach

    I'm trying to look how the formula made on this http://www.gamedev.net/reference/programming/features/quatcam/page2.asp" . I want to know how this formula was derived. I tried to look on Quaternions and Rotation Sequences book but they use sin/cos which is so different on this. N.w = a.w*b.w...
  18. A

    Apparent Angular Size in Pinhole Camera Concept

    Hi This is regarding the pinhole camera concept regarding apparent angular size. If we take the simultaneity train and assume the lightning strikes are behind translucent ends of the observers car and that the observer has two pinhole cameras facing forward and back: In the view of the...
  19. I

    Help with my large mirror and camera.

    This isn't homework, I really have this setup. :-) I have an 18" mirror with an 80" focal length. The light from a point light source at twice that distance (and offset to the side slightly) bounces it's beams off the mirror and back to form a perfect image of itself next to the light if you...
  20. R

    Pinhole Camera Question: Calculating Distance for 1-Inch Image of a 20 Ft Tree

    How far would you have to stand from 20 ft tree so the image in a pinhole camera is 1 inch long? I feel like the teacher left out a piece of information...please help I am stumped.
  21. Andre

    Capturing Nature's Small Wonders: Comparison of Camera Configurations

    It's a great joy to capture small creatures big on the screen without them even noticing it. There are several ways to do that. I used to utilize my old Panasonic FZ-18 bridge camera with a close up lens. Preferably #2 or 2 dioptries or 50 cm focus distance, with a moderate zoom 8-12x you get...
  22. DaveC426913

    Better in my eye than in my camera

    This was really cool in-person. I didn't take the time to check my camera settings, so it didn't record as well as I'd have liked. I am calling it a crepuscular rainbow. This is a pic of sun beams (crepuscular rays) streaming through the clouds - into a mist of raindrops. So, this tiny...
  23. 0

    Can I Use a 2/3" CCTV Lens on a 1/3" Camera?

    i have a camera with 1/3 " format. I have a cctv lens in front of it with a focal length of 50mm. In order to improve my FOV i intend to use a cctv lens of a smaller focal length, and the vendor is providing me a smaller focal length for a 2/3 " format. i want to know if a cctv of say 25mm...
  24. F

    Triggering a Camera for Train Detection: Ideas and Resources

    What do you guys think would be the best way to trip a camera so that it goes off only for when a train is passing through it? Sorry I can't get anymore specific than that. I was thinking laser tripping device but was wondering if there is anything out there that maybe used that ya'll might...
  25. 0

    Increase FOV of Camera: Simple Tips & Tricks

    i have a camera with the horizontal field of view as 40 cm, and vertical around 30 cm noted at around 5m from the camera. I wish to increase the FOV of the camera. Please suggest me a few ways to accomplish that. thanx
  26. D

    Exploring the Physics of Cameras: Tips and Resources for Your Project

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  27. M

    10.1 megapixel camera, object is 18,877.90 feet away from me, can I see it?

    I have a 10.1 megapixel camera. If an object is 18,877.90 feet away from me, will my camera be able to see it? This is a non-school related project that I am doing in order to be awarded scholarships. If anybody knows how I can calculate this answer please let me know. Please include all...
  28. E

    Making photos under the water with common camera

    Making photos under the water with common camera. Is this possible. Or this need different optics.
  29. L

    Can my digital camera function at -20 degrees Celcius?

    After 5 loyal years, my Canon Digital IXUS 400 has given in... i can take pictures, but there are red stripes all over them. Maybe it is something fixable, but I've been meaning to replace the thing anyway. So, i put it in a plastic sealed bag in the freezer, which the thermometer indicates...
  30. rootX

    Build Your Own Network with Linksys & Camera

    I want to use Linksys wireless router and camera such that camera can communicate with my adapter and broadcast the video to the network. Then I want to access the information sent by my camera on the computer. It doesn't have to be a camera - even a led light (I guess simpleer..the better)_...
  31. X

    Troubleshooting Vivitar Camera Vivicam 3765

    I have a vivitar vivicam 3765. I installed the software on my computer that came with the camera, and I have the cord. But I can't seem to put the pictures from my camera onto my computer. The batteries are new, and I have it on PC mode, but it still won't work. Suggestions?
  32. russ_watters

    Stargazing Saturn with new DMK, grayscale camera

    I have a new camera - a DMK, grayscale camera. Here's one of my first Saturn shots with it... My best yet.
  33. J

    Total Energy of Camera Capacitor

    Homework Statement A flash attatchment for a professional camera stores energy in a capactior. When a picture is taken, all of the charge is converted to energy, and the capacitor is fully discharged. A.Assume the battery charging the capacitor is a 300V battery. When the light flashes, it...
  34. Andre

    Buying a new (compact) camera?

    That's what somebody thought about on chat, yesterday (MiH). So you could go to the shop and exchange a random piece of hardware for some paper sheets with portraits of past presidents. But you could also look into the matter somewhat closer and see what the specialists recommend based on...
  35. G

    How does the f-number of camera lenses affect image area?

    I was reading on the f-number of lenses for cameras...somewhere in the text, they stated that the area of the image is proportional to q2, in which q is image distance. I figured the area to be proportional to q, but I don't really see it as q2...so how does this work out?
  36. wolram

    New Camera Owner: A Journey Through Time

    Criticism is welcome, but seeing as this is the first camara i have owned since the box brownie please be kind http://picasaweb.google.co.uk/marlow.robin The farm house is circa 1650 but parts of it go way back in time.
  37. M

    Infra red port for board camera

    Does anyone know how to make an infrared port for a board camera to transfer video to a pocket pc, the camera is analog with RCA output.
  38. R

    Calculating Slide Distance from Projector Lens & Image Dimensions on Screen

    the dimensions of the picture on a 35mm color slide are 24X36 mm,an image of the slide is projected on a screen 9.00 m from the projector lens.the focal length of projectorlens is 150mm. 1-- how far is the slide from the lens 2-- what are the image on the screen. Plz some body help me...i m...
  39. Cyrus

    Find the Best Digital Camera Under $200.00

    I need to get a new digital camera that's under $200.00 and has good quality pictures and video. What do I look for in a good camera? I know its not the MegaPix because the camera I have now is 5.0MP but sucks. So, its got to do with the quality of the lense. Any ideas? Thanks!
  40. M

    How to add memory to board camera

    hello, I have a small 2x2cm board camera that I want to add video storage capability (about 10 seconds of video at VGA resolution). How much would this increase the size of the camera? and approximately how much would it cost. Thank you.
  41. V

    Calculating Resolution of Space Camera for Imaging Earth

    If I have a camera orbiting in space way above the Earth, and it has a diffraction limited resolution of 4.1*10^-7 m (diameter of airy disc), then how can I find out the corresponding value if the lens is supposed to take images of the Earth?
  42. C

    Does the Thin Lens Formula Apply to Pinhole Cameras?

    Homework Statement It's not a specific problem, persay... I'm working on a science lab and I'm supposed to be deriving the height of an image created by a pinhole camera. Since I'm in a condensed Physics course, we are expected to figure out formulas on our own. I keep finding this formula...
  43. W

    High speed camera projectile motion

    We are trying to calculate the acceleration of gravity using a quarter inch ball bearing and a high speed video camera. The ball bearing it shot at 6 m/s across a grid .5 meters long. The high speed camera is 1.8 meters away and records the position of the ball at 250 frames per second. We...
  44. W

    Help Projectile Motion and High Speed Camera

    We are trying to calculate the acceleration of gravity using a quarter inch ball bearing and a high speed video camera. The ball bearing it shot at 6 m/s across a grid .5 meters long. The high speed camera is 1.8 meters away and records the position of the ball at 250 frames per second. We...
  45. W

    Help Projectile Motion High Speed Camera

    We are trying to measure the accleration due to gravity with a high speed camera. The set up is as follows. A 1/4 inch ball bearing is shot at 6 m/s across a half meter grid. The high speed camera is 1.8 meters away and perpendicular to the grid. The camera is records the ball at 250 frames...
  46. P

    Optimal Aperture Width for Solar Eclipse Pinhole Camera

    Homework Statement Consider a pinhole camera with depth R = 0.1 m used to observe a solar eclipse. Suppose the sunlight has wavelength \lambda = 5.8 \times 10^{-7} m. Estimate the optimal value of the aperture width w. Homework Equations Hint: balance the geometetrical distortion of...
  47. J

    Rotating a Camera on a Sphere: Finding a Coherent Direction

    Homework Statement I have a task to move a camera attached to a robot arm along the surface of a sphere. The requirments are, * Z axis of the camera coordinate system should always point to the origin of the sphere. * X-Y plane of the camera coordinate system shold be always in the...
  48. ~christina~

    Has this happened to your camera?

    Well, it was not fun yesterday. I went to the zoo and when I arrived there my camera was working fine. Then after I went to eat, I tried using it again, but could not preview the pictures I took. I would press the preview button and the picture would show for 1 second and then flash...
  49. N

    Camera Translations: Find Translation & Rotation

    I'm making a physics game engine, and I have some decent camera functionality. Essentially, the camera has a translation (vector) and a rotation (quaternion), and functions exist to easily move the camera along any of seven degrees of freedom (pitch, yaw, roll, strafe, elevate, move, zoom)...
  50. P

    Electrim CCD camera EDC-1000TE

    hi, I have ccd camera EDC-1000TE and i want how to interfcace with matlab thanks a lot sorry for my english
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