The Art of Photography

Taking a great artistic photo (versus just shooting a random snapshot and hoping for the best) requires two fundamental things:

  1. a well-developed artistic eye that composes pictures using the elements and principles of design
  2. an understanding of how the camera controls and lighting conditions affect the resulting image

 

Main Parts of a Camera

We’ll look at some of these in more detail, but let’s begin by knowing the most important parts of any camera.  These all have strong effects on the image exposure and quality:

  1. Light-sensitive medium. (we’ll call it the sensor from now on).  Film or digital sensor (CCD or CMOS).  This is at the back of the camera, in the focal plane.  It captures the image so it can be stored in memory and transferred to a printer or computer, or developed in the case of film.  More on Sensors
  2. Lens – focuses light on the sensor, and can also magnify the image  More on Lenses
  3. Aperture – the opening that light passes through between the lens and the sensor, reducing or increasing the amount of light the sensor is exposed to.  Also affects Depth of Field.  Created by a mechanical Iris, similar to the human eye.  Measured in “F-stops”.  Each standard F-stop represents a doubling of the amount of light.  Low F-stop = larger aperture = more light and shallower Depth of Field.  The highest F-stop on most cameras is 16 or 22, meaning a small pinhole with deep Depth of Field.  Typical digitals have a lowest F-stop around 5.6, not as wide as SLR lens that can open to 2.8 or even 1.8.  Zoom lenses tend to have smaller apertures, so they can’t let as much light in.  More on Aperture    More on Depth of Field
  4. Shutter – mechanism to allow light to pass through to the sensor only for a certain time period.  The faster the shutter speed, the less light the sensor is exposed to, and also the less blur from camera shake or movement of the subject.  Mechanical curtains in an SLR, and electronic in most digitals.  Measured in fractions of a second.  E.g. shutter speed 60 means an exposure of 1/60th of a second.  Common high speeds are up to 1000 or 2000, whereas a long exposure might be ¼ of a second, or even several seconds.  More on Shutter Speed Effects: Motion Blur and Frozen Action

 

CMOS sensor (images from How-Stuff-Works.com)

Iris showing narrow and wide aperture  (F-16 and F-2.8)