1 / 16

Camera Basics

Camera Basics. How cameras work Film vs Digital Taking control. Film Camera. Viewfinder Cameras Image viewed through a simple lens providing an image of how the final picture will look. Light travels from the subject through the lens to the film Parallax error. Film Camera.

wayne-mcdowell
Download Presentation

Camera Basics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Camera Basics How cameras work Film vs Digital Taking control

  2. Film Camera • Viewfinder Cameras • Image viewed through a simple lens providing an image of how the final picture will look. • Light travels from the subject through the lens to the film • Parallax error

  3. Film Camera • Single Lens Reflex (SLR) • Photographer looks directly through the lens to see the picture. • Light from the lens reflects off an internal mirror up to the viewing system. • Mirror swings out of the way to allow light to expose the film. • Includes a prism to invert the reversed image

  4. Digital Camera • Lenses work just like film cameras • BUT, lenses refract light onto computer chips rather than film • Contains a logic board with microprocessors and transistors. • Microcontroller unit (MCU) – main chip • Image sensor – converts light refracted by lens element into a series of electrical charges

  5. Parts of the camera • Diaphragm • Opens and closes to control the amount of light entering the camera • Diameter of the diaphragm is the aperture • Shutter • Controls how long the film is exposed to light • Digital – shields the image sensor from constant exposure

  6. Making Images • Film responds chemically • Active ingredient – gelatinous emulsion filled with light-sensitive crystals • Crystals contain traces of silver • When light hits the film impurities in the crystals attract the silver atoms into clumps • Stronger light = larger clumps • Development process enlarges the clumps making them visible

  7. Image Sensor • Image sensor responds electronically • Sensor is composed of a layer of silicon covered with a grid of square electrodes • Silicon has negatively charged particles – electrons • When light passes through the electrodes - the electrons scatter • Voltage applied to the electrodes attracts the free electrons into clusters - photosites

  8. Image Information • Images are stored as a collection of tiny squares • Pixels = picture elements • Resolution: number of pixels captured by the image sensor. • Masking: pixels clipped away around the perimeter of the image • Interpolation: invention of extra pixels

  9. Image size and Compression • JPEG • Joint Photographic Experts Group • Compresses image data • Smaller picture files • Utilizes a lossy compression scheme • Some image data is sacrificed during the compression process • Common WWW format

  10. Image size and Compression • TIFF • Tagged Image File Format • Uncompressed image information • Can utilize LZW compression • Lossless compression scheme • Only redundant image data is dumped • Larger file sizes • Used when quality is important • Print and publishing format

  11. Example • Uncompressed • Sheep, sheep, sheep, sheep, sheep • Lossless compression • Seven sheep • JPEG • sheep

  12. Exposure • ISO – International Standards Organization ratings • The image sensors’ sensitivity • Comparable to film rating • Lower ISO – more light necessary for picture • Ordinary film 200 - 400

  13. Exposure • Aperture • Opening of the diaphragm to let in light • F-stops • Each stop represents a factor of 2 in the amount of light permitted. • Affects the depth of field • How much in front of or behind the object will be in focus. • The smaller the aperture, the greater the depth of field, the more of the photograph is in focus.

  14. Aperture f/22 f/8 f/2.8 f/2 f/5.6 f/11

  15. Shutter Speed • Shutter speed controls the length of the exposure • Closed shutter means no light • Numbers indicate fractions of a second • Each is either half or double the length of time of the one next to it. • Parallel to the aperture

  16. Equivalent Exposure Settings

More Related