Let There Be LightThe 3 Fundamental Elements of Digital Photography

Photography is light...● The basic principle of all photography is the capture of an image through the

absorption of light onto a medium

● In the past, this was onto silver plates, and eventually film - today it is done

digitally onto a sensor and store on a memory (SD) card.

● The sensor must receive and absorb the light for this to occur.

● The 3 main factors that influence light absorption are:

● APERTURE

● SHUTTER SPEED

● ISO

APERTURE● An aperture is an opening that lets light in

● You can compare the aperture in your camera to the pupil of your eye.

● The wider the aperture is, the greater the amount of light that reaches the sensor.

● Aperture is measured in F-Stops. The SMALLER the F stop the GREATER the

amount of light that enter the camera (F2 = more light - wide open) (F18 = less

light)

● The aperture is controlled by a dial or a ring around the lens.

● Aperture has a DIRECT impact on SHUTTER SPEED, ISO and DEPTH OF

FIELD

● Each F-stop you go up DOUBLES the amount of light let in

Aperture Explained:

A Visual Guide:

Aperture ● APERTURE PRIORITY - in this mode, you choose the aperture and the camera

picks the shutter speed and ISO .

● Your task - discover how to control APERTURE on YOUR camera and the

SCHOOL camera. Try several different apertures. (Small, Middle, Large). record

the ISO and Shutter Speed. What is the impact on the image? Report what you

found.

APERTURE AND DEPTH OF FIELD● depth of field refers to how much of the foreground and background will be in

focus in an image

● Shallow depth of field means that only the foreground will be in focus, the

background will be blurred. This is great for portraits, close-ups (macro) and

sports.

● A small aperture (large f stop #) will create a wider depth of field.

SamplesWhat is the difference?

Shallow DOFNotice the blurred background

F1.8 1000/sec

Wide Depth of FieldForeground and

Background are

sharp.

Why change?

Shutter Speed● Shutter speed refers to how LONG the sensor is exposed to the light

● It is controlled by a metal curtain that opens and closes with a mechanical shutter

or an electronic shutter that turns the sensor on and off

● Shutter speed can be compared to you blinking

● The more light there is (Wide Aperture - low f stop) - the faster the shutter can

open and close

● When there is less light (Small aperture - large f stop #) the shutter has to stay

open longer.

● Shutter speed is measured in fractions of a second 1/500 is faster than 1/60

● To prevent blur, your shutter speed should be equal to of faster than your focal

length. (Amount you are zooming)

A FAST SHUTTER SPEED - FREEZES THE ACTION

F 1.8 , 1/4000 SEC.

SLOW SHUTTER SPEED - absorbs more light - blurs the action

ISO - THE SENSITIVITY OF THE SENSOR● The ISO refers to the sensitivity of the camera’s sensor

● INCREASING the ISO allows the sensor to become more sensitive and require

less light in dark situations

● The trade off is a decrease in picture quality due to digital “noise” or pixelation

● Cameras with larger sensors (Mirrorless, DSLR, Full Frame) can do this better

than “point and shoot” or cell phone cameras.

● You can set the AUTO ISO to a maximum level in your camera to limit noise

APERTURE-SHUTTER SPEED-ISO : THE CONNECTION

CHANGE ONE - IMPACT ALL...