EXPOSURE What is a camera and how does it take pictures? What is a camera and how does it take...

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Transcript of EXPOSURE What is a camera and how does it take pictures? What is a camera and how does it take...

  • EXPOSUREWhat is a camera and how does it take pictures?

  • What is a camera?A device that records and stores images by capturing reflected light and projecting it onto a film or sensorThe word camera comes from the latin word camera obscura which means dark chamber

  • Light bounces off objects?Ever worn a black shirt outside in the sun?What happens when you wear a white shirt in the sun?Ever seen a shiny, metal object bounce light all over the ceiling?

  • Pin Hole CamerasFirst camera-like device invented by the Ancient Chinese & GreeksConsists of a pin-sized hole that allows light to enter a box through a tiny hole and project an image of the object onto a surfaceFilm or Sensor

  • How does a camera take pictures?Cameras have a small opening at one end (called the aperture) that allows light to enter through a lensThe light travels through the lens and a light sensitive film or digital sensor is exposed to the lightA picture is a copy of the reflected light that bounces off of the objects in the scene

  • EXPOSUREThe total amount of light that is allowed into the camera during the process of taking a pictureOften measured as Exposure Value - EVControls how light and dark our pictures are when we take them.

  • MANIPULATABLESSHUTTER SPEEDAPERTUREISO (Film Speed)Photographers can adjust these three settings ontheir cameras to adjust how much light is let into the camera:

  • Camera SettingsManual - you adjust everything yourselfAperture Priority - you set the aperture, the camera will set everything else to matchShutter Priority - you set the shutter speed, the camera will set everything else to matchProgram / Automatic - the camera does it all for you (but it might not do it the way youd like it to!)

  • SHUTTER SPEEDThe length of time that the cameras shutter is openDetermines the length of time that light can reach the film or sensorThe longer the shutter is open, the more light that is let throughDark places (indoors) require a slower shutter speedSlow speeds will blur movementFast speeds will stop movement

  • Shutter

  • SHUTTER SPEEDSMeasured in fractions of a second1/60 is the slowest shutter speed for hand held pictures to avoid blur from hand movement1/250 slowest speed to stop action (running, cars, sports, water moving, etc)Bulb - stays open for as long as you hold the shutter down

  • SHUTTER SPEEDSFreezing movement1 second1/3 second1/30 second1/200 second1/800 secondNotice how the water is blurry with slower shutterspeeds (1, 1/3, 1/30) and is more crisp and frozen in motionwith the faster shutter speeds (1/200, 1/800)

  • Slow, long shutter speeds captures light over a longer period of time

  • Long ExposureSlow Shutter Speed

  • Want to take a picture in low light?Night timeIndoorsTRIPOD

  • Dont have a tripod?You can use ANY FLAT, STILL surface as a tripod!TableChairLedgeLadderCabinetCounter topthe floor

  • Does your camera have a timer setting?Set the camera up, put it on a short timerStep back and let the camera take the pic!

  • Long ExposureSlow Shutter Speed

  • Long ExposureSlow Shutter Speed

  • Long Exposure

  • Long Exposure

  • Long Exposure

  • ACTION!Fast Shutter Speeds to stop movement

  • Short ExposureFast Shutter SpeedStops Action!

  • Short ExposureFast Shutter Speed

  • Short ExposureFast Shutter Speed

  • Short ExposureFast Shutter SpeedStops the speed of a bullet!

  • Short ExposureFast Shutter Speed

  • Short ExposureFast Shutter Speed

  • Short ExposureFast Shutter Speed

  • ApertureThe opening in the lens that opens and closesBigger the opening, more light let inSmaller the opening, less light let inWorks just like your pupil in your eye!

  • Measured in f-stopSmaller number = bigger hole = more lightLarger number = smaller hole = less light

  • How do shutter and aperture work together?As a photographer, your job is to... find a balance between the shutter speed you want and the necessary aperture to capture the image.Accurately capture the light to get a good value scale (blacks, grays and whites)Stop action and avoid blurriness

  • ISO aka Film SpeedThe level of sensitivity of the film or sensorLow ISO = less sensitive = need a lot of lightHigh ISO = very sensitive = dont need as much lightLow ISO = outdoors, sunlight, flashHigh ISO = indoors, sports, night, low light

  • Why not use a high ISO all the time?The higher your ISO, the more you will see grain and digital noise in your pictureUse as low an ISO as possible!Better cameras cope with this better than cheaper onesMore important that megapixels!Pixels

  • Low vs High ISO200 ISO800 ISO

  • Which has the high ISO?

  • Which has the high ISO?

  • RECAPCamera = device that captures reflected lightFirst camera was the pin-hole invented by the Ancient Chinese & GreekExposure = the amount of light the film or sensor is exposed toPhotographers control how much light is let into the camera by manipulating:shutter speed - how fast the mirror opens/closes aperture - the opening in the lens bigger opening, smaller f-stop number, more light let in.smaller opening, bigger f-stop number, less light let in.ISO - how sensitive the film or sensor is to lightlower ISO = less sensitive = less grain = less noiseHigher ISO = more sensitive = more grain = more noise