Exposure- Shutter speed, Aperture and ISO

My tutor offered an optional session, to go over the concept of Exposure and its components; Shutter speed, Aperture and ISO. I found this session so useful, as I had knowledge on each area, however this just confirmed what I knew and further enhanced my knowledge on areas that I was not so sure on. This will be very helpful and important information for my assignment one, as it is using film photograph, where getting all these components right first time is very important as you don’t have photoshop or live previews to improve and see where you have gone wrong. Making sure your settings on your camera are very important, especially on film cameras, as you have to wait to process and develop each film, so to find out you have all the wrong settings would be extremely annoying. When working on my assignment, I will always keep in mind all this information and make sure I use it.

ISO– how sensitive your sensor of film is to light

  • Bigger the number= greater sensitivity to light
  • bigger number= more grain/ ‘noise’
  • low ISO needs lots of light but its not as grainy
  • 3200- Very high grain, high sensitivity, could be used for low lit, indoor rooms at night
  • 1600- High grain, high sensitivity, could be used for low lit, indoor rooms in the day, dusk outside
  • 400- Medium grain, medium sensitivity, good for overcast days or well lit indoor spaces
  • 100- Low grain, low sensitivity, primarily used outside on brighter days or with studio lighting
  • 50- Very low grain, low sensitivity, bright days or long exposures

Aperture– how wide your lens is: will dictate how much light hits the film, ‘a hole’

  • F16= not much light
  • bigger the F number= smaller hole, less light in
  • smaller aperture (bigger number)= greater depth of field (how much is in focus)
  • shallow depth of field= less in focus
  • deep depth of field= lots in focus
  • in darkroom if you want your print to be darker, you need a lower F number as it lets more light hit the developing paper meaning the print is darker, you could also increase the light exposure time because this would also mean more light hits the paper. If you want your print lighter then do the opposite, so reduce the light exposure time or increase the F number.

Shutter speed– the length of time the camera allows light to enter, dictates how much light will hit the film

  • bigger the number= faster shutter speed, less light allowed to hit the film/sensor
  • bigger the number= freeze in action, as number gets smaller if there is movement in the shot the picture will become blurred.

Measure light in Stops

  • increasing the stops= increasing the amount of light
  • An increase of 1 stop is twice the amount of lightAn increase of 2 stops is 4 times the amount of lightAn increase of 3 stops is 8 times the amount of light
  • An decrease of 1 stop is 1/2 the amount of lightAn decrease of 2 stops is 4 times less lightAn decrease of 3 stops is 8 times less light
  • with each setting there is a different of one stop between the main numbers.
  • for shutter speed the main numbers are: 1, 2, 4, 8, 15, 30, 60, 125, 250
  • for aperture: f2.8, f4, f5.6, f8, f11, f16, f22, f32
  • for ISO: 3200, 1600, 400, 100, 50
  • in the Zone System there is one stop of light between each zone
  • to maintain the exposure the same- if you increase the shutter speed, you need to decrease the F number, and visa versa

_iso_chart

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