Digital Photography 103

Digital Photography 103 Learning Exposure

Presented by

Rick Hicaro

v 3.0

GOAL:

To have a better command over exposure and learn how to use it effectively to express your vision as a photographer

PURPOSE:

To understand the principles of photographic exposure

Learn how to correctly set exposure

Learn how to use exposure creatively

OBJECTIVES:

Learn how exposure works

Learn how a digital camera meters exposure

Hands-on exercises

Morning Session: 9:00AM to Noon

Exposure Defined

Steps to Proper Exposure

Lunch Break: Noon to 12:45PM

Afternoon Session: 12:45PM to 4:00PM

Hands-on Workshop

Part 1 - Exposure Defined

Exposure Defined Trinity of Photography

Exposure

Total amount of light used to create a photographic image, either on film or digitally. Exposure metering determines aperture and shutter speed settings for correct exposure.

Composition

The arrangement of subject, foreground, and background, coupled with the effects of lighting and shadow in a photographic image.

Lighting

The natural illumination from ambient light, and/or the subjective placement of artificial lighting in a photograph.

Exposure Defined Trinity of Photography

Exposure

Total amount of light used to create a photographic image, either on film or digitally. Exposure metering determines aperture and shutter speed settings for correct exposure.

Composition

The arrangement of subject, foreground, and background, coupled with the effects of lighting and shadow in a photographic image.

Lighting

The natural illumination from ambient light, and/or the subjective placement of artificial lighting in a photograph.

Exposure Defined Principles of Light for Photography

LIGHT…

… is the ‘paint’ of the photographer

… varies in intensity, direction, and color

… paints highlights, renders color, creates shadow

… falls off geometrically with distance

… is metered by the camera

This measurement of light is called, “ Exposure ”

Exposure Defined Sources of Light

Natural light

Direct, unshaded sun light is pure white

Skies and clouds are indirect sources

Moonlight is reflected, indirect sunlight

Artificial light

Candle light

Tungsten lighting - light bulbs, photofloods

Fluorescent lighting - standards and balanced

Electronic flash - Approximates sunlight

Unusual light sources

Infrared

Phosphorescence / Chemiluminescence (“glow sticks”)

Lightning

Plasma (neon signs)

Nuclear decay

Exposure Defined Why “What you see is not always what you get”

The Human Eye

Very high resolution (125 MP)

Wide exposure range from extreme high to low light

Infinitely variable focus, exposure, & white balance

Continuous and continual exposure

Camera

Low resolution (3 to 39 MP)

Narrow exposure range

Single exposure

Pre-determined focus, exposure, & white balance values

Small computer processes and stores image

Exposure Defined Dynamic Range

Dynamic (luminance) range covers gradations of light from total blackness to full white.

Human eye can cover wide dynamic range (24 stops)

Digital cameras cover narrow dynamic range

Higher ISO can push dynamic range off the edges.

Exposure Defined Why Control Exposure?

Cameras are programmed to take ideal photos

The camera’s metering doesn’t fit all circumstances

Camera seeks to average all exposures

Camera’s Goal: 50% light level = 18% gray

Extremes (white/black) become gray

Low light = muddy contrast and color

Camera fails in extreme circumstances

Adverse or mixed lighting

Motion in subject

High contrast (lighting or color)

No creative control

Going beyond Program mode

Exposure Defined What is Exposure?

Exposure is a metering of the amount of light that will eventually strike a photographic medium (film or image sensor) in order to control the effect of light and shadow on that medium.

Exposure determines both the technical and aesthetic qualities of a photograph.

Technically perfect exposure does not always make for the most aesthetically pleasing photo.

Exposure Defined How is Exposure Measured?

Exposure is measured by the camera’s internal metering system

Level of Exposure determined by the ISO number

The camera ‘sees’ the image according to the metering mode (dynamic, center weighted, spot)

You can control what the camera sees by metering mode and framing of the subject

Exposure Defined How is Exposure Metered?

Exposure is metered by aperture size and shutter speed

The optimum level of Exposure is set by ISO number

There is a reciprocal relationship between shutter speed and aperture, i.e., as one increases, the other decreases

Exposure is measured in STOPS

Each STOPS represents a stepped change in aperture, shutter speed, or ISO

Each STOP doubles exposure

Exposure Defined What is Exposure?

A Technically “perfect” exposure does not always make for the most aesthetically pleasing photo.

Exposure Defined Controlling Exposure

Exposure is controlled though:

Aperture

Controls the intensity of light entering the camera

Controls the sharpness of image (depth-of-field)

Shutter speed

Controls the timing of light entering the camera

Controls motion of subject

Fast shutter = freeze motion

Slow shutter = blur motion

ISO number

Adjusts the sensor’s ability to capture light

High ISO - Less light for proper exposure

Low ISO - More light for proper exposure

Governs aperture and shutter speed settings

Exposure Defined Controlling Exposure - Definitions

Aperture

Designated by ‘f/[number]’ where ‘f’ is the focal length of lens

Example: 200mm lens/2.8 = 71.4mm aperture size

Shutter speed

Designated by fractions of a second

Example: 1/15 sec, 1/30 sec

Times > 1 sec denoted by quotes

Double quote (“) = # seconds

Single quote (‘) = # minutes

Example: 1’ 30” = one minute, 30 seconds

ISO number

Follows geometric multiples of 100

50, 100, 200, 400, 800, 1600, 3200, 6400, etc.

Close relative of ASA numbers (film speed)

“ Stops” - The Units of Exposure :

Shutter speeds stops (in seconds, slow to fast)

Aperture stops (“f-stops”, wide to narrow opening)

Example of how shutter speed (top) and aperture (bottom) relate over a constant exposure

Exposure Defined Controlling Exposure via Shutter Speed

Shutter speed meters the timing of the exposure

Controls blur = apparent movement

Fast shutter freezes motion (sports, wildlife)

Slow shutter blurs motion (waterfalls, fountains)

Exposure Defined Controlling Exposure via Aperture

Aperture size controls depth of field (DoF)

Wide (f/2.8 to f/5.6) = shallow DoF

Narrow (f/8 and up) = deep DoF

Exposure Defined Priority Modes

Scenic modes (Landscape, portrait, Cloudy, Night time, Close-up)

Camera sets aperture, shutter, ISO, resolution, and flash

No control

Program Mode

Camera sets shutter speed and aperture

You control ISO and flash (if applicable)

A perture Priority

You control aperture, camera controls shutter

S hutter Priority

You control shutter speed, camera controls aperture

Manual Mode

You control both aperture and shutter speed

Camera acts as a ‘dumb’ meter

Exposure Defined Which Mode to Use?

The Camera runs the show

You have NO control

( P )rogram Mode

You can control ISO and flash (if applicable)

You + Camera = Semi-automatic control

( A )perture Priority

( S )hutter Priority

Total Manual control

( M )anual Mode

You control aperture and shutter speed

Camera is a ‘dumb’ meter

The Camera = Total automatic control

You have no control

(P)rogram Mode

You control ISO and flash (if applicable)

You + Camera = Semi-automatic control

( A )perture Priority

( S )hutter Priority

Total Manual control

( M )anual Mode

You control aperture and shutter speed

Camera is a ‘dumb’ meter

Program Mode (P)

Camera in controls both aperture and shutter speed

Use for quick shots (no time to prepare)

Aperture Mode (A)

User controls aperture / camera controls shutter speed

Controls depth-of-field

Blur background

Landscapes

Shutter Mode (S)

User controls shutter speed / camera controls aperture

Freezes action: sports, moving subject

Creative blurring: waterfalls, rain, dynamic movement, light streaking

Manual Mod e (M)

Expert mode / full creative control over exposure

Onboard meter only indicates exposure

User controls both aperture and shutter speed

Exposure Defined Exposure Modes – Aperture Preferred

Aperture preferred mode - water and bucket analogy

Shallow Depth of Field - Photo taken at f/4.2

Deep Depth of Field - Photo taken at f/22

Exposure Defined Exposure Modes – Shutter Priority

Shutter preferred mode - water and bucket analogy

Exposure Defined Shutter Priority Mode

Freeze action

Exposure Defined Shutter Priority Mode

Blur action

Exposure Defined ISO Number

What is ISO?

ISO - International Organization of Standards

Sets exposure requirements for photography and other imaging media

Digital camera ISO range: 80 to 3200 (varies by camera)

What do ISO numbers do?

ISO numbers determine the correct level of exposure (EV)

Low ISO increases light requirement for proper exposure

High ISO decreases light requirement for proper exposure

Lower ISO = better image quality

Higher ISO = More digital noise in photos

Auto ISO

Automatically adjust ISO number according to conditions

Takes away photographer’s control

Exposure Defined Exposure Control – ISO Number

How ISO setting affects exposure

Exposure Defined Which ISO Number to Use?

Native ISO (100 or 200 typically) - Best for all around use

ISO 400

Overcast day

Well-lit interior shots

Action shots (faster shutter speed)

Long telephoto lens (300mm+)

ISO 800

Dim lighting

Fast action (fast shutter + small aperture)

Ultra telephoto (600mm+)

ISO 1600 and up

Very dim lighting, moonlight

Fast action (fast shutter + small aperture)

NOTE: will introduce visible noise, esp. dark areas

Exposure Defined Using ISO Numbers

Lower ISO

Pro’s

Better quality photos, more even exposure

Moderate contrast

Little or no noise in photo

Con’s

Increases light requirement for proper exposure

Blurry or underexposed photos in low lighting

High ISO

Pro’s

Shoot in low light with no flash

Helps capture action/motion

Allows use of less expensive lenses

Con’s

Contrasty photos

Digital noise (especially dark areas)

Exposure Defined Basics of Exposure - Quiz

What mode would you use to make a waterfall appear soft and billowy?

To keep a bee on a flower in focus, but blurring the background, which exposure mode would you use?

Aperture priority

What stops are between f/2 and f/16?

f/2.8, f/4, f/5.6, f/8, f/11

Part 2 - Steps to Proper Exposure

Steps to Proper Exposure Know where the Camera is “Looking”

Metering zones define where a camera is metering

Main types: Dynamic, center weighted, spot

Exposure (and focus) can be ‘locked’ in some cameras

Steps to Proper Exposure Which Metering Mode to Use

Matrix/dynamic metering - Use when subject, foreground, and background have even contrast and lighting.

Center weighted metering - Use when subject has distinct exposure difference with foreground and background (color, lighting, movement, etc.).

Spot metering - Targets a small portion of subject to meter . Use with high contrast or strong lighting, especially backlighting.

Steps to Proper Exposure Basic Technique - Matrix metering

1. Aim viewfinder center on main subject

Steps to Proper Exposure Basic Technique - Center Weighted

1. Aim viewfinder center on main subject

Steps to Proper Exposure Basic Technique - Spot metering

1. Aim spot meter center on main subject

Steps to Proper Exposure Getting the Color Right - White Balance

White Balance

Determines overall tonality and hue of the image

Camera automatically sets white balance

Corrections can be made with filters or by white balance adjustment

“White” varies by light source

Tungsten (red-orange tint, indoor incandescent, candles)

Fluorescents (greenish tint)

Outdoor (white light, direct sunlight)

Shade (bluish tint, indirect sunlight)

Cloudy (bluish tint, indirect sunlight)

Electronic flash (for electronic flash)

Set manually in mixed lighting situations

White balance is measured in °Kelvin

Always correct for white balance if you are shooting .jpg

Set using white balance function

Use custom white balance if in mixed lighting

If shooting RAW, W/B can be corrected in post-processing

Use a gray card or a pure white surface as a calibration target while shooting.

Steps to Proper Exposure Using a Gray Card to Lock Exposure

A gray card can help your camera’s ‘dynamic’ / ‘evaluative’ metering make a better exposure judgement

How:

Hold gray card in subject’s lighting

Zoom in on gray (fill frame)

Take exposure reading (lock exposure)

Recompose and take the photo

Camera ignores large swings in tone

Full tonality in photo is insured

Steps to Proper Exposure Using your Camera - Quiz

Depth-of-field is controlled by which exposure factor?

To blur the motion of a fountain, which mode would you use?

Shutter priority

Which metering setting measures a very small area?

Spot metering

Lunch Break!

Hands-on Workshop

Hands-on Workshop Exercise - Learning Your Exposure Modes

Set camera to (S)hutter Priority mode

Change shutter speed

How does aperture change?

Set camera to (A)perture mode

Change aperture

How does shutter speed change?

Set camera to (M)anual mode

Change aperture and shutter

How does meter display correct exposure?

Locate and change EV compensation

Change to +1, +2, –1, –2

How do exposure settings change?

Locate and change white balance settings

Hands-on Workshop Exercise - Understanding Manual Mode

Set camera to (M)anual mode

Find exposure meter scale

Adjust aperture and shutter to center meter reading

Take a photo

Adjust aperture/shutter to over- and under expose

Take photo

Report observations

Q: How can manual mode give you added control over exposure?

Hands-on Workshop Exercise - Working with ISO numbers

Set ISO to lowest setting (ISO 100 or 200)

Set camera to any priority mode

Take photo in a low light scene (note settings)

Increase ISO number

Take photo in same scene (note different settings)

Repeat until all ISO level are used

Compare photos taken

Report observations

Q: How would you use ISO creatively?

Hands-on Workshop Exercise - Controlling Depth-of-Field

Set camera for Aperture Preferred Mode (A Mode)

If camera has no ‘A’ mode

Set to ‘Portrait’ mode for shallow depth-of-field

Set to ‘Landscape’ mode for deep depth-of-field

Take depth-of-field shots

Use f/8 or higher for long depth-of-field

Use f/5.6 or lower of shallow depth-of-field

Watch shutter speed, adjust ISO is necessary

Report observations

Q: How would you know when to use Aperture mode?

Hands-on Workshop Exercise - Capturing Motion

Set camera for Shutter Priority Mode (S Mode; T v on Canon )

If camera has no ‘S’ mode

Set to ‘Night’ mode for blurring motion

Set to ‘Action’ mode for freezing motion

Take action shots

Slow shutter (<1/30 S) = Blurs motion

Fast shutter (>1/125 S) = Stops action

Try panning shots

(use <1/15 s)

Continue panning after pressing shutter

Report observations

Q: How could you catch a fast sequence of movement?

Hands-on Workshop Exercise - Working with EV compensation

Set camera for any priority mode

Take photo of a subject against black background

Adjust EV compensation, take photo

Black object: –1, –2, –3

White object: +1, +2, +3

Try Manual mode to control exposure

Compare photos

Which setting shows true colors?

Repeat with subject against white background

Report observations

Q: How can you use EV compensation creatively?

Hands-on Workshop Exercise - Comparing Metering Modes

Set camera for aperture mode, dynamic metering

Set subject against a brightly lit background (e.g., window) and take photo

Set camera to center-weighted metering and take photo

Repeat with spot metering

Report observations

Q: How does metering affect exposure?

Q: How can you use metering creatively?

Hands-on Workshop Exercise - Getting Creative with White Balance

While under tungsten or florescent lighting, set W/B to “Daylight” or “Flash”

Take a photo and observe result

Q: Where can this be used artistically?

While under sunlight, set W/B to “Tungsten” or “Florescent”

Take a photo and observe result

Q: Where can this be used artistically?

Shoot a photo under mixed lighting

Set any white balance and take a photo

Use a gray card or white surface to set a custom white balance

Retake same photo and compare

Q: When would you use a custom W/B?

Hands-on Workshop Exercise - Setting Exposure with a Gray Card

Set camera to any priority mode (manual preferred)

Place subject in light

Take photo of subject using dynamic metering

Have subject hold gray card (or place in scene facing light)

Zoom-in on gray card

Lock-in exposure reading

P, A, or S mode: half depress shutter and hold

Manual: set aperture and shutter manually

Take photo

Compare to first photo

Q: How did the gray card affect the outcome?

Part 3 - Exposure Hints and Tips

Exposure Hints & Tips When & How to Override Exposure Controls

When to override automatic modes (P, S, or A)

Extremes in exposure (snow, very light/darks subjects, fast moving)

Creative use of exposure (deliberate over- or underexposure)

To override, use Manual mode or ±EV compensation

±EV compensation

Use in either P, A, or S mode

+ EV increases exposure

– EV decreases exposure

Does not work in (M)anual mode

Be sure to reset before next shot or turning off camera

Exposure Hints & Tips Shooting in Natural Lighting

Avoid hard, overhead, direct sunlight

Causes squinting and hard shadows in eyes

High contrast and loss of shadow detail

Shoot in shadows to even out lighting

Watch out for blue cast (set WB to shadow or cloud)

Overcast days are best

Soft, even lighting with soft shadows

Medium to low contrast (greater detail)

Watch out for blue tinting (set WB to shadow or cloud)

Use fill flash for backlight or shadowed situations

To bring out surface detail, bring in light from an angle

Exposure Hints & Tips Shooting in Artificial Lighting

Watch white balance (use WB presets)

Always set WB for fluorescent lighting (remember to reset)

Watch for mixed lighting (daylight + tungsten, etc.)

Use a tripod if shutter speed longer than 1/60 sec

No tripod? Brace on wall, pole, back of chair, etc.

Raise ISO only if others methods fail

Exposure Hints & Tips Shooting High Contrast

Problem: High contrast scenes

Bright sun = very high contrast

Deep, featureless shadows

Blown out highlights

Wide color variations (white on black, bright colors, etc.)

Solution 1 : Meter an area representing 18% gray (gray card)

Solution 2 : Block sunlight from subject (if possible)

Solution 3: Use reflector to open shadows and add detail

Solution 4 : Shoot in the shadows (use ‘Cloudy’ WB setting)

Solution 5 : Meter brightest area, adjust EV +1/2 stop

Exposure Hints & Tips Shooting with Backlighting

Problem: Light source comes from behind subject

Solution 1: Use flash to fill-in subject and balance lighting

Solution 2: Use reflector to reflect light onto subject

Solution 3: Meter very close to subject. Lock setting (some cameras). Pull back, compose photo and shoot

Solution 4: Meter your hand facing towards you (simulates shadow level on subject). Lock exposure, recompose on subject, shoot.

Solution 5: Change ±EV compensation to properly exposure subject (background may be overexposed) .

Exposure Hints & Tips Freezing Action

Use high shutter speed (1/250 or higher)

Use higher ISO to allow faster shutter speeds

Use tripod for maximum sharpness

Electronic flash can also freeze action

Exposure Hints & Tips Light Modifiers - Lens Filters

Most useful filters:

Neutral density - reduces light input (‘slows’ exposure)

Use if light is too bright for long shutter speed (blurring motion)

‘Slows down’ exposure (longer shutter, wider aperture)

Graduated ND great for sunsets/sunrises, bright sky/dark foreground

Circular polarizer - reduces glare, intensifies colors

Better sky coloration, more cloud contrast

Eliminates unwanted glare and reflections

Deepens coloration

Acts like neutral density filter adding 2-3 stops

Exposure Hints & Tips Sunrise & Sunsets

Great colors, but very hard to determine exposure

Do not look or point camera directly into sun

Meter on a nearby cloud

Test & reshoot

Use graduated neutral density filter to lower exposure on sun while preserving foreground detail

Impossible to get foreground and sun in perfect exposure without post-processing help

Digital Photography 103 - Learning Exposure Conclusion - Remember the Basics

Take control of your photographs…

Move away from (P)rogram mode

Use (A)perture and (S)hutter modes for creative shots

Shoot, shoot, then shoot some more

Success comes through persistence

Shoot intentional photos

Even with pros, 1% success rate is good

Read books, take classes, ask questions

Digital Photography 103

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