A Visual Comparison of Lighting Setups


Generally, light is more widely distributed when a light source is larger, and the reflections of that light sourceseen on the subject as highlightsare larger as well. The shape of the light source also influences the shape of the highlights. For example, a rectangular soft box will create rectangular highlights on a flat glass or metal object like a beer stein or knife, while a round reflector creates more rounded highlights. The difference is not as pronounced on spherical objects, such as fruit.

The following tables illustrate the impact that a variety of reflectors, umbrellas, soft boxes, and mirrors have on the highlights, shadows, contrast, and detail of the same food subject. You can clearly see the exposure range of each light source in the photos that follow. They are documented by incident light meter readings, which show the numerical difference in exposure between the highlights and shadows. It is important to understand what these numbers represent. When the difference between two readings is great, less detail is captured because there is a large degree of contrast between the highlights and shadows. In addition, the shadows become darker and have less detail. The edges do become sharper. For example, when the difference in exposure between the highlights and shadows is three f-stops, the photograph has more contrast and less detail in the shadows than if the difference between the highlights and shadows is one f-stop.

Note

As mentioned earlier, it is very important to expose properly for the highlights because it is difficult to put detail back into the image during the retouching process.


The following chart shows the numerical relationship between f-stops. Each box represents a difference of one full f-stop, moving vertically in the same column. The difference between f2.8 and f4, or between f10 and f14, is one f-stop. The difference between f8 and f22, or between f3.5 and f10, is three f-stops. Moving left or right, each box in the chart represents a change of one-third of an f-stop. Simply count the number of whole and one-third f-stops between two incident light meter readings to determine the difference in proper exposure. For example, the difference between f5.6 and f14 is two and two-thirds f-stops. The difference between f2.8 and f5, or between f9 and f16, is one and two-thirds f-stops. The difference between f7.1 and f8 is one-third f-stop, because f8 is one box away from f7.1 moving left to right. Similarly, the difference between f5 and f11 is two and one-third f-stops.

Let me attempt to make sense out of these numbers through the following tables. The tables have a photo of each light source accompanied by a verbal description, my light reading from an incident light meter of the highlights and shadows, and the f-stop setting on my camera when I took the picture. In most cases, I chose a setting halfway between the two extremes (when the difference was two or fewer f-stops) in order to achieve a properly exposed photograph. In other cases, when the extremes were greater, I chose a setting closer to the highlight meter reading. This ensured that I would get enough detail in the highlights.

ReflectorsLight Source 6 Feet Away

Table 7.1 visually illustrates the difference in the light output and quality of some reflectors that I own and use. Standard reflectors typically come with flash heads when you purchase them.

Table 7.1. Reflector Light Output Table

Photos

Description

Incident Meter Reading: Highlights/Shadows

Camera Setting: f-stop

5" reflector: Medium light output, medium shadow, and medium contrast range

2 1/3 f-stop range

 

Wide shot

f7.1/f3.2

f4.5

Close up

f7.1/f3.2

f4.5

9" reflector: High light output, sharp shadow, and high contrast range

2 2/3 f-stop range

 

Wide shot

f14/f5.6

f10

Close up

f14/f5.6

f10

10" reflector: Medium light output, medium shadow, and medium contrast range

2 1/3 f-stop range

 

Wide shot

f11/f5

f7.1

Close up

f11/f5

f7.1

22" reflector: Low light output, soft shadow, and low contrast range

1 f-stop range

 

Wide shot

f7.1/f.5

f4

Close up

f7.1/f.5

f4


Tip

Don't forget that the bare flash tube is an excellent light source on its own without any attachments. I often use a bare flash bulb to mimic sunlight when shooting in my studio. After all, the sun doesn't use any reflectors, umbrellas, or soft boxes.


Note

Be aware that manufacturers do offer reflectors that are other sizes. They have different reflective surfaces and various lighting characteristics. Try them out and see how the quality of the light varies.


UmbrellasLight Source 6 Feet Away

Umbrellas are very portable and useful lighting tools to have on location and in the studio. They are also very economical. Because of their round shape, umbrellas reflect a circle of light onto the subject. This is visible as white spots or highlights. The size of the umbrella and its distance from the subject affect the size of the reflection. The color of the umbrella's surface materialsilver, white, zebra (silver and white), gold, or what have youaffects the detail and sharpness of shadows and the overall color cast of the photograph. Table 7.2 illustrates the effect of using various umbrellas.

Table 7.2. Umbrella Light Output Table

Photos

Description

Incident Meter Reading: Highlights/Shadows

Camera Setting: f-stop

33" umbrella with silver interior and black exterior: Highlight output, sharp shadow, and high contrast range

3 f-stop range

 

Wide shot

f8/f2.8

f5.6

Close up

f8/f2.8

f5.6

40" umbrella with white interior and black exterior: Medium light output, soft shadow, and low contrast range

1 2/3 f-stop range

 

Wide shot

f8/f4

f4

Close up

f8/f4

f4

White 40" shoot-through umbrella: High light output, medium shadow, and medium contrast range

2 f-stop range

 

Wide shot

f8/f4

f5.6

Close up

f8/f4

f5.6

Zebra (silver and white) 60" umbrella: Medium light output, soft shadow, and low contrast range

1 2/3 f-stop range

 

Wide shot

f5.6/f3.2

f4

Close up

f5.6/f3.2

f4


With the 33-inch umbrella with silver interior and black exterior, the difference in proper exposure between the highlights and shadows is three f-stops. These photographs have a lot of contrast and less detail in the shadows. The silver surface is highly efficient at reflecting light, and shows more texture than a white surface. It provides a brighter light. In food terms, I would call it "zesty." With the 40-inch umbrella with white interior and black exterior, the difference between the highlights and shadows is one and two-thirds f-stops. The resulting photographs have a lighter shadow with softer edges. As you can see with the 40-inch white shoot-through umbrella, the difference between the highlight and the shadow is two f-stops. I set my camera for the f-stop halfway between the two settings to get a photo with detail in both the highlights and the shadows. The 60-inch zebra umbrella uses a similar contrast range and exposure to the 40-inch white umbrella; the main difference is the size of the highlight. The combination of silver and white surfaces provides a good balance of reflection, texture, and softness in the shadows.

Soft BoxLight Source 6 Feet Away

A soft box is another diffusion lighting tool that creates the quality of light similar to the light that shines through a north-facing window. It has a good f-stop range for capturing detail in the highlights and in the shadows of an image. The soft box (or bank light) is portable and breaks down easily for use on location. It is more expensive and is not as time-efficient in setting up as an umbrella. Most soft boxes have internal diffusion materials that help soften the light even further to distribute light evenly over the entire set. Various soft boxes have interchangeable panels for the interior reflective surfaces. The exterior shape of the soft box varies as well, and there are many sizes available to purchase. This influences the size and shape of the reflections that are visible on shiny objects in the food photograph. Table 7.3 illustrates the effect of using a 22x30-inch soft box from various positions.

Table 7.3. Soft Box Light Output Table

Photos

Description

Incident Meter Reading: Highlights/Shadows

Camera Setting: f-stop

22x30" soft box: Medium light output, soft shadow, and medium contrast range

2 f-stop range

 

Wide shot

f5.6/f2.8

f4

Close up

f5.6/f2.8

f4

Wide shot with soft box angled down

f6.3/f2.8

f4

Wide shot with soft box at a straight angle

f5.6/f2.8

f4


Tip

In general, I prefer to use a 2x3-foot soft box with a silver interior and an internal diffuser when I photograph food, and a white shoot-through umbrella when I photograph people. The catch lights are different shapes, and the quality of the light varies. How I want the shot to look will determine what type of lighting I ultimately use.


Soft Box with Grid Spot BacklightLight Source 4 Feet Away

In Table 7.4, I kept both my camera settings and my main light source (a soft box) constant. The only variation involved the power setting to the grid spot that I used as a backlight.

Table 7.4. Soft Box/Grid Spot Light Output Table

Photos

Description

Main/Grid Spot

Camera Setting: f-stop

Lighting setup

f6.3/Not used

f22

Wide shot without grid spot

f6.3/Not used

f22

Wide shot with grid spot, small highlight

f6.3/f8 (2/3 f-stop range)

f22

Wide shot with grid spot, medium highlight

f6.3/f16 (2 2/3 f-stop range)

f22

Wide shot with grid spot, large bright highlight

f6.3/f32 (42/3 f-stop range)

f22


Soft Box with Grid Spot Backlight and MirrorsLight Source 4 Feet Away

Table 7.5 illustrates the use of a grid spot backlight and mirrors. The results show that by adding mirrors, you add specular highlights. Depending on the angle, distance, and shape of the mirrors, the catch light will vary on the subject. This is the professional way to achieve detail and highlights that make my food photographs stand out.

Table 7.5. Soft Box/Grid Spot/Mirrors Light Output

Photos

Description

Main/Grid Spot

Camera Setting: f-stop

Lighting setup: Soft box only

f5.0/Not used

f3.5

Fruit shot: Wide shot, no highlights in shadow

f5.0/Not used

f3.5

Lighting setup: 32x40" white board

f5.0/Not used

f3.5

Fruit shot: Wide shot, large soft milky white reflection in shadow

f5.0/Not used

f3.5

Lighting setup: 32x40" white board

f5.0/f5.6 (2/3 f-stop range)

f5

Fruit shot: Wide shot, specular highlight toward back

f5.0/f5.6 (1/3 f-stop range)

f5

Lighting setup: 32x40" white board, one mirror

f8/f8 (no f-stop range)

f7.1

Fruit shot: Wide shot, specular highlight toward back, new highlight on right front

f8/f8 (no f-stop range)

f7.1

Lighting setup: 32x40" white board, two mirrors

f8/f8 (no f-stop range)

f7.1

Fruit shot: Wide shot, additional highlight on toward left back

f8/f8 (no f-stop range)

f7.1

Lighting setup: 32x40" white board, three mirrors, overhead shot

f8/f8 (no f-stop range)

f7.1

Lighting setup: 32x40" white board, three mirrors, overhead shot

f8/f8 (no f-stop range)

f7.1

Fruit shot: Wide shot, additional highlight on left toward front

f8/f8 (no f-stop range)

f7.1


Soft Box from Different Angles

In Table 7.6, I moved the soft box and showed you how the highlights, shadows, and background change. The last photograph in Table 7.6 used direct flash, which yields no depth. Not surprisingly, it's the worst photo of the bunch.

Table 7.6. Soft Box Light Output

Photos

Description

Main/Grid Spot

Camera Setting: f-stop

Lighting setup: Soft box from above at a level angle

f16/f8

f11

Fruit shot: Wide shot

f16/f8

f11

Lighting setup: Soft box from above tilted at a forward angle

f14/f7.1

f10

Fruit shot: Wide shot

f14/f7.1

f10

Lighting setup: Soft box from the right

f11/f5.6

f8

Fruit shot: Wide shot

f11/f5.6

f8

Lighting setup: Soft box aimed directly at the subject

f16/f8

f16

Fruit shot: Wide shot

f16/f8

f16





Digital Food Photography
Digital Food Photography
ISBN: 1592008208
EAN: 2147483647
Year: 2006
Pages: 84
Authors: Lou Manna

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