CASTLEFORD CAMERA CLUB DSLR Introduction-Session 1 The Exposure Triangle

Co"Correct” Exposure May be defined as an exposure that achieves the effect the photographer intended

“Correct Exposure” as determined by the camera “Underexposed” – but achieving the picture the photographer wanted

“Overexposed” to achieve the effect the photographer wanted

3 major factors in creating an exposure ISO Aperture Shutter Speed If you adjust one, the others will need adjusting The Exposure Triangle

THE EXPOSURE TRIANGLE

ISO International Standards Organization

Choosing the film sensitivity was one of the many factors photographers had to consider when using film in their cameras

ISO Since digital cameras do not use film but use image sensors instead, the ISO equivalent is usually given.

The Camera Sensor

ISO The important thing to understand, is that each step between the numbers effectively doubles the sensitivity of the sensor. So, ISO 200 is twice more sensitive than ISO 100, while ISO 400 is twice more sensitive than ISO 200. ISO 1600 is sixteen times more sensitive to light than ISO 100, so on and so forth.

ISO The downside to having a high ISO is that we lose clarity in our images. Increasing the ISO tends to mean the resulting photographs get more grain/noise.

Typical ISO Settings 100 or 200 ISO for sunny and bright daylight 400 ISO for cloudy days, or indoors for window light portraits 800 ISO for indoors without a flash 1600+ ISO for really low light situations

THE EXPOSURE TRIANGLE

Aperture

The aperture is made up of a number of interlocking diaphragm blades that open to allow the light into the camera.

Depth Of Field

THE EXPOSURE TRIANGLE

Shutter Speed

Shutter Speeds

Shutter speeds are measured in fractions of seconds e. g Shutter speeds are measured in fractions of seconds e.g. 1/60 of a second or 1/2500 of a second.

Aperture / Shutter Speed Relationship

Aperture / Speed Relationship

Aperture / Speed Relationship

Taking The Picture

The first thing you need to determine is the type of effect you want from your image: Depth of field Frozen action shot Motion blur Once this has been determined you can either set your Aperture or Shutter speed and then adjust the other to produce the intended exposure.

BRINGING IT ALL TOGETHER Aperture: Small F number = big hole in lens  = more light into the camera Shutter Speed: Slower shutter speed = more light into the camera ISO: Higher number = more sensitivity (but may be grainy)

Final Thought ! Remember –if at first, you are getting a bit confused or you are still trying to master your camera “ Its a million times better that someone be amazed by your photographs then your technical prowess”