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< Product Resources < Lighting Resources
Introduction to Lighting
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Controlling, Modifying Light and Color
Controlling Light
After covering the quantity of light and where it comes from, we need to discuss how we are going to change the quality of light in order to achieve optimum results.
Light coming from a point source will be very specular (undiffused - hard shadows) in nature. There are different ways to diffuse (make light softer – soften shadows) light to make it softer.
A rule regarding the quality of light is: the larger the light source and the closer it is to the subject, the softer the light will be. Bouncing light off an umbrella for example, makes the light source change from the size of the bulb to the size of the umbrella, making it bigger and diffusing the light. Similar effects are achieved by bouncing light off a wall or other large surface.
You can also pass light through a diffusion gel, a large diffusion panel, or a softbox. In each case the light source is now the size of that modifier, in turn making it larger. The modifier scatters the light so that it comes from all directions filling in all the surface angles of the subject thereby reducing the contrast significantly.
Light Modifiers
There are many ways to modify the light reaching the subject. They include umbrellas, reflectors, light banks, soft boxes, filters, diffusers, grids, baffles etc. Creative lighting has almost no limits, thanks to the diversity of products available. The appropriate section of the B&H website will go into greater detail describing the full range of light modifying tools to help you achieve just about any lighting effect you desire.
Light and Color
We use a term called “Light Balancing” to describe how warm or cool the light is (usually referred to in degrees Kelvin). The other term is “Color Correction” which deals more with pure color. In order to achieve accurate color results, you must have the light balanced and color corrected.
Light Balancing
Color temperature is measured in degrees Kelvin. The color temperature of light is measured by taking a black body radiator (an object or system which absorbs all incident radiation upon it and re-radiates that energy back out), When the black body radiator is heated to a certain temperature, it starts to glow orange.
As more heat is applied, the temperature increases, getting bluer (less orange), more towards white light and eventually when the black body radiator gets to the upper heat levels, it becomes even more blue, until it won’t change anymore.
This color is then compared to various light sources, and assigned the temperature of the black body radiator when heated to that color. The following list displays some common light sources with their average color temperatures.
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Kelvin Temperatures
Common Light Sources |
| Clear Blue Sky |
10,000 - 15,000 |
| Overcast Sky |
6000 - 8000 |
| Sunlight, noon high altitude |
6500 |
| Sunlight average |
5400 - 6000 |
| Electronic Flash |
5400 - 5600 |
| On-camera flash |
5400 - 6000 |
| Daylight blue flood lamps |
4800 |
| Studio photo floods |
3400 |
| Studio tungsten bulbs |
3200 or 3400 |
| Studio quarts bulbs |
3200 or 3400 |
| household lighting |
2500 - 3000 |
| 200w bulb |
2980 |
| 100w bulb |
2900 |
| 75w bulb |
2820 |
| 60w bulb |
2800 |
| 40w bulb |
2650 |
| Single candle |
1200 - 1500 |
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To balance the light for this situation, we can either put a blue gel on the light to remove the orange, or attach a blue filter to the camera lens.
In summary, light balancing deals with the warm or cool aspect of the light (color temperature). With this knowledge an overcast day can be made to look sunny or a sunset can be made to look like midday, simply by choosing the appropriate color filter.
See the chart of Light Balancing filters and their shift in degrees Kelvin.
Warming Filters |
| For The Camera |
Shift (°Kelvin) |
| 85 |
5500k - 3200k |
| 85 C |
5500k - 3800k |
| 81C/D |
5500k - 4500k |
| 81 A/B |
5500k - 4900k |
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Cooling Filters |
| For The Camera |
Shift (°Kelvin) |
| 80A |
3200k - 5500k |
| 80 C/D |
3200k - 4100k |
| 82 A/B |
3200k - 3500k |
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The advantage of digital image creation, video or still, is that you are able to white balance or correct the color temperature electronically.
Color Correction
If you have ever taken a picture of someone with daylight film in a room lit by fluorescent lights, you will have noticed that your photos have a green cast to them. Light-balancing filters will only make this color cast warmer or cooler. The only way to eliminate a color cast is to use the opposite or complimentary color of that cast to neutralize it. In this case, a magenta |
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| (the opposite of green) filter of the same intensity of the green shift is used to cancel the green effect. |
The color wheel illustrates how complimentary colors work. Note on each side of the color wheel is the opposite or complimentary color. For instance if the light source is green, add magenta filtration to correct it. If blue, add yellow to correct it. And if red, add cyan to correct it.
The easiest and most accurate way to determine which filter to use to correct your color balance is to use a color meter.
Digital image capture facilitates color correction through the use of image editing computer software. Naturally, starting with the right color balance, saves time.
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