ISO and White Balance ISO Refers to the

ISO and White Balance

ISO Refers to the light sensitivity of the sensor ISO – International Standard Organisation HIGH ISO value means the sensor will be MORE sensitive to light, meaning it will take LESS LIGHT to get the right exposure Similar to Film Speeds in 35 mm format

ISO Typically ranges from 100 -1600 Newer Digital cameras have a higher range (up to 64000) Using High ISO values causes the sensor to produce much more heat, which creates digital “noise” in images.

ISO Noise is similar to film grain and causes loss of fine detail in images It is more visible in dark parts of an image and is generally more noticeable when displayed on screen than in print

ISO

ISO

ISO Some cameras claim to have “Digital Image Stabilization” This just means that the camera will automatically increase the ISO in order to allow a faster shutter speed Faster Shutter Speed will reduce the likelihood of camera shake, but high ISO will most likely result in a grainy image.

Exposure Compensation Way to control your exposure 8

Cameras Meter n n Selects an aperture/shutter speed combination that it believes will give a properly exposed picture. sometimes determines the wrong exposure value needed to correctly expose the image. * 9

Exposure Compensation n Slightly over-exposing the image or slightly under-exposing the image. 10

Why do we use it. n To ensure a properly exposed photo. 11

Universal Symbol 12

Exposure Compensation n n Exposure Value + Adds more light to pictures n n Makes Lighter Subtracts light from pictures Makes darker +/- 2 EV * 13

EV COMPARISION EV = -2 EV = -1 EV = 0 EV = +1. 3 EV = +1. 6 EV = +2 14

Normal Exposure n Most average scenes reflect 18% of the light that falls on to them. 15

Bright Scenes n Reflect more than 18% of the light. n n Beach Scenes Bright sand Snow covered landscapes You need to subtract exposure (make darker) 16

Dark Scenes n Reflect less than 18% of the light falling on them. n n Deep shadows Dark Foliage Black Cloth You need to increase your exposure (make lighter) 17

Others n Subject against a very light background. n n Subject against very dark background. n n Main subject will be dark Main subject will be to light. Scenes with High Contrast 18

Summary n n To lighten a picture, you increase the exposure (+). To darken an image, you decrease the exposure (-) 19

White Balance • Critical to “look” of the photograph • Instructs camera computer how to interpret colors it sees • Set based on temperature (degrees Kelvin) of the primary light source • Incorrect White Balance can cause colors that are too warm (red) or too cool (blue)

Here is a list of some common light sources and their colour temperature in Kelvin. Temperature —–> Typical Sources 1000 K —–> Candles; oil lamps 2000 K —–> Very early sunrise; low effect tungsten lamps 2500 K —–> Household light bulbs 3000 K —–> Studio lights, photo floods 4000 K —–> Clear flashbulbs 5000 K —–> Typical daylight; electronic flash 5500 K —–> The sun at noon 6000 K —–> Bright sunshine with clear sky 7000 K —–> Slightly overcast sky 8000 K —–> Hazy sky 9000 K —–> Open shade on clear day 10, 000 K —–> Heavily overcast sky 11, 000 K —–> Sunless blue skies White balance

White Balance Goal • Achieve a neutral colorcast in your photo • Get whites to look white • Get colors to look like what you saw when you took the photo

White Balance Importance • JPEG vs. RAW • When true color rendition is critical – Weddings – Portraits – Product Photos

Setting White Balance • Before shooting – Auto – Camera Menu choices (e. g. , direct sunlight, cloudy, shade, flash, fluorescent (7 choices), incandescent, set color temp) – Manual Preset • Gray card photo • Expodisc • Neutral color photo

Expodisc

White Balance

Adjusting White Balance • After shooting – JPEG – not directly adjustable – RAW – fully adjustable in most processing software • Menu choices • Gray card photo • White point/Gray point tools

Examples Hi Temp Merc Vapor (7200 K) Sodium Vapor (2700 K)

Examples AUTO WB Cool White Fluorescent (4200 K)

Examples Incandescent (3000 K) Set Gray Point on Cheerleader’s Arm

Examples AUTO WB Set Gray Point on Cheerleader’s Arm