Photographic Lighting - Contrast and Shadow Fill (4.5c)

Requirement

6 images

Purpose

To experiment with contrast using flash as the light source (by diffusion, reflection and distance from the subject)

Technical learning

• Contrast is the difference between light and shadow
• 2 important roles for strong shadow: it adds to (a) the graphic design of an image and (b) the atmosphere and emotional appeal (see below)
• However, shadow sacrifices detail. Shadow in-fill can enhance detail but increasingly makes for a flatter image.

Strong shadows - graphic design

Stairs
Aleksandr Rodchenko

Girl with a Leica
Aleksandr Rodchenko

Light Contour Map
Ralph Morse

Strong shadows - emotional impact

Lionel Shriver
Manuel Vazquez

Miles Davis
Irving Penn

Truman Capote
Irving Penn

Big Cloud, Los Angeles
Mitch Dobrowner

Trees Clouds
Mitch Dobrowner

• Difficult to change outdoors in daylight (other than waiting for the light to change), it can be managed indoors with photographic lighting with/without reflectors
• 3 ways to change contrast: (a) alter distance between light source and subject (further away increases contrast), (b) set up a second light source and (c) use a reflector (reduce contrast), or not/ using black card/ velvet
• Reflectors fill in shadows when set up opposite to the light source: their strength depends on the shininess of their surface
• Shadow fill adds more detail but as its effect increases so does the flatness of the image

Exercise instructions

• Set up a still life
• Obtain a large white card (2 x 3 feet) and aluminium foil (as a reflector)
• Choose a background away from walls that allows access from the sides
• Place the camera on a tripod level with the subject
• Set up a flash unit 2/3 feet away from and at right angles to the subject

Take 6 images as follows:

• 2 x flash unit: 1 with diffuser, 1 without
• 2 x reflector (white card): at 3 feet from subject, then 1.5 feet from subject
• 2x aluminium foil: 1 x dull surface outwards, 1 x shiny surface outwards
• Organise images in order of contrast, highest first

Images and review

The Petrol Can

Naked Flash
Hard Shadows, particularly of cap
on front of petrol can

Flash diffused by Soft Box
Soft edges and moderately more
detail in the shadows

...White Card Reflector at 36 inches
more detail emerges on side of can

...White Card Reflector at 18 inches
even more detail than at 36 inches

...Aluminium Foil (dull side) at 18 inches
slightly more detail than using a white card
reflector at the same distance

...Aluminium Foil (shiny side) at 18 inches
more detail again, although the position
of the reflector is evident on the side of the can
(unintended effect)

...Aluminium Foil (shiny side) at 36 inches,
more detail than white card reflector at that distance

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Photographic Lighting - The Lighting Angle (4.5b)

Requirement

11 images

Purpose

• To experiment with using diffused light at different angles

Technical learning

Direction and elevation

• 2 dimensions to the position of light source: (a) direction and (b) elevation
• Both have a major impact on how viewer reads image
• Photographers describe direction variously - by angles, points of compass, clock positions or relationship to the subject (as in chart below)
• Photographers sometimes describe elevation as between 'high' and 'low', but more useful to consider the angle at which light strikes the subject, since this takes account of the height of the light and its distance from the subject

Impact of lightening angles
David Praekel, 'Lighting'

Backlighting and rim-lighting

• Both are effective in revealing shape
• Back light is behind the subject directed towards the camera. This creates a silhouette sitting in a bright background. 
• Rim light comes round the edge of the subject from a source behind or to the side so that it reveals the edges of the subject

Top and base lighting

• Top lighting with a softbox, with reflectors to throw light towards the front of the subject, is common in product advertising
• Base lighting requires the subject to be placed on a transparent surface and lit from below

Exercise instructions

• Pick a small subject (e.g. sculpture) so that you have several planes to show differences in shadow and light
• Use a tripod (and keep in the same location during shoot)
• Set the subject against a plain background
• Move the flash and diffuser around the subject as you shoot
• With the light level with the subject, (1) front, (2/3/4) side, (5) behind
• With the light 45 degrees above the subject, (6) front, (7) side, (8) behind
• With the light 90 degrees above the subject, (9) directly overhead, (10) slightly in front, (11) slightly behind
• Compare the results 

Images and review

Still life# 1 Bowl

• The 2nd attempt: the 1st attempt was OK for learning, I just didn't like the images much. So having another go, in addition to reinforcing the learning, made me happier with the result
• Improvements were mainly from the use of a black card background and conversion to monochrome

Still life# 2 Tennis Ball

• Use of yellow tennis ball on a red rush table mat, provides contrasts: one of adjacent warm colours, the other of textures. 
• The shape of the ball provides a useful way to show the modelling effect of the flash. 

Key points of flash impact

• Location, surface area, diffusion of shadow
• Subject and background
• Intensity on illuminated surfaces

1. Bowl

1. Front - level with subject

No back shadow but some light
reflection from inner glass onto black surface,
with shadow pattern as well.
Detail bleached out by flash, but for the difference
in the reflection from the black card 
the image has no depth

2. Three quarter - level with subject

Shadow thrown onto background in the opposite
direction to the flash, right hand edge of bowl
is also in shadow. More texture revealed.

3. Direct left  - level with subject

Shadow cast to the side, but light seeping through
glass lights up inside right of bowl.
Not particularly appealing - mildly chaotic
Strange shadow at 8 o'clock (unsure what
caused it - might be light reflected from the background?)

4. One quarter - level with subject

Unexplained shadow (however, can this really
be reflected light at work? Doubt it)

5. Back - level with subject

Replaced the black back board with my DIY
polythene A3 diffuser.
Reveals the shape in silhouette.

6. Front - at 45° elevation

Bleaches detail but 45 degree elevation 
casts a small shadow behind to add some depth, 
compared to image #1 above

7. Direct left - at 45° elevation

The diagonal shadow across the face of the bowl
is interrupted by light passing through the
lattice. Neat shadow on the base of the set.

8. Back - at 45° elevation

Interesting illumination of the structure, almost
a film negative or infrared effect.
Shadow on the base is nearly as
appealing as the rendering of the image.

9. Overhead

Top half illuminated, bottom half of bowl not.
Slight loss of symmetry of shadow on base suggests
that flash wasn't directly overhead.

10. Overhead - slightly backward

Again the effect of light passing through the structure
is evident here

11. Overhead - slightly forward

Top 2/3 rds lit by flash, soft shadow
across remaining 1/3rd of bowl

2. Tennis Ball

1. Front - level with subject

Eliminates nearly all shadow on ball and mat

2. Three quarter - level with subject

Creates a shadow on the ball (25% of its
surface) and makes illuminated side look brighter. 
Also, diffuser creates a graduated shadow,
light to dark in the direction of the light source.
Long hard shadow on mat.

3. Direct left  - level with subject

Shadow now covers c. 50% of subject,
left hand edge has a luminous glow
(Is this an illusion caused by contrast, or is
this is a real increase in brightness?)

4. One quarter - level with subject

The ball is in silhouette, but for a
crescent shaped area of brightness on
the same side as the flash. 
Rear side of mat lit, front side not.
Faint lens flare.

5. Back - level with subject

A silhouette (created by shooting through the 
framed greaseproof paper).
Lens flare corrected in Photoshop.

6. Front - at 45° elevation

Mostly even lighting, modest
shadow at base of ball, diffused on ball but
hard on mat.

7. Direct left - at 45° elevation

Diagonal shadow on subject, oblong shadow 
on the mat

8. Back - at 45° elevation

Near silhouette. 
Edge round top half of ball
is rim lit

9. Overhead

Shadow covers 25% of lower part of ball
and is highly diffused on the subject. Hard shadow
thrown underneath, mimics shape

10. Overhead - slightly forward

Shadow covers lower half of ball.

Hard shadow

underneath, distorted shape

11. Overhead - slightly backward

Shadow covers bottom 2/3rds
of subject and appears harder
on the face of the ball. Hard shadow

underneath, even more misshapen

Photographic Lighting - Softening the Light (4.5a)

Requirement

2 images

Purpose

• To compare diffused with naked flash light
• To develop still life photography skills

Technical learning

Still life - key pointers

• Use a simple backdrop (to avoid distraction from subject)
• Make light contrasty: vary the strength of light from different sources (e.g. main light = strongest, 2nd light = fill in shadows)
• Pay attention to light angles: (a) light(s) to subject, (b) subject to camera. Varying light angle and viewpoint is key to discovering best presentation of perspective
• Light for texture and depth: side light works best
• Light for shape: side light also works best, also add highlights across the edge of subject

Role of photo lighting

• Treat photographic lighting as a supplement with unique possibilities
• Some advantages of photographic lighting (vs. natural light) are:  (a) useful for shooting small subjects that the photographer can control and (b) more effective for photographing indoors

Lighting options

• Options include: camera in-built flash, separate flash unit (battery or mains) and tungsten (mains powered) unit
• Some advantages of tungsten (vs. mains flash) are: (a) it is cheaper, (b) you can preview the lighting effect, (c) it does not need synchronisation with the shutter and (d) it does not require a separate light meter
• Some advantages of mains flash (vs. tungsten) are: it (a) can drown ambient light and
•  (b) produces less heat so enabling the use of important light modelling attachments (e.g. soft box diffusers, umbrellas etc)

Managing light intensity

• The intensity of light falling on the subject varies by distance by the Inverse Square Law, doubling the distance, reduces the light intensity four fold

Using diffusers

• Naked lights produce bright highlights and hard shadows as well as distribute light indiscriminately around the scene. This effect can be softened by diffusers 
• Diffusion models more softly, reduces shadow and reveals more detail

Exercise instructions

Create a DIY diffuser

• Create a frame of cardboard or wood
• Tape white greaseproof paper over window (other options: specialist 'scrim' or 'spun', milky plexiglas)
• Attach frame to stand and place between flash and subject 

Set up a still life

• Experiment with the placement of the flash unit before deciding where to position it
• Take 1 shot with naked flash, another with diffused light
• Compare the results in the treatment of highlights and shadows

Images and review
I made 2 identical diffusers from greaseproof paper taped to a cardboard frame, so that I could assess the impact of doubling up on diffusing the flash light.

Tennis Ball

Naked Flash
Hard shadow on the grey card and
high contrast between lit side and shadow
side of the ball

1 x diffuser
Softer transition to shadow across the face of
the ball and weaker shadow on the grey card 

2 x diffuser
Even softer effect than in the previous image

Available Light - Outdoors at Night (4.4b)

Requirement
12 to 20 images

Purpose
To explore the range of lighting and colour effects in low light

Technical learning

• Dusk rather than night enhances the skyline of any night time cityscape

Camera craft issues to consider:

• Camera Shake - Low light lowers shutter. Use a tripod and a cable release 
• Noise - Raising ISO to increase shutter speed to offset motion blur will increase the risk of noise, the extent depends on the quality of the camera's sensor. So, minimise the increase in ISO consistent with motion effect required
• Improper Auto Focus - Auto focus tends to malfunction, so use manual focus
• White Balance - Colour temperature of light sources are often difficult to anticipate, so shoot RAW and adjust colour in post processing
• Exposure - Some conditions are likely to exceed the camera's ability to operate at an acceptable exposure, so you may have to set shutter speed manually (bulb). This requires experimentation to get the correct exposure
• Shadows - Flash or other artificial light creates strong shadow, so consider background lighting as well as lighting the subject

Exercise

• Go to a well lit city centre
• Use a tripod and cable release
• Shoot as many images of (a) floodlit buildings, (b) brightly lit store fronts, (c) large interiors with many people and (d) a raised view over a busy road

Images and Review

City see from Hays Galleria in twilight
Dark enough to reduce shadow, light enough
to retain some detail

HMS Belfast in Twilight
Eyes adjust, camera doesn't
Lower light enhances colours

London Bus crossing Tower Bridge
Lower light enables moving lit objects
to create dramatic motion blur

Burlington Arcade at night
Pattern of colour and light adds
to sense of perspective

Office block, More London
Glass buildings become well lit
and rich in detail

Waterloo Station, 7.30pm
High ISO (6400) to freeze movement