|
Many churches are now incorporating live video projection into
their services. Others broadcast their services to local and national
television affiliates. In order to produce a high-quality result,
lighting designers must have an understanding of video lighting
techniques to meet the challenges of this technology. This article
will cover a full range of techniques for video lighting design,
from the simple parish with one camcorder, to broadcast-quality
design.
Having lit numerous broadcasts of live and taped events for local
and national organizations including lighting video productions
for PBS, NBC, and A&E networks, the first question I ask when
lighting a video production is: How many cameras are you using,
and where will they be located? This will tell me how many
angles I have to be concerned about. Remember, the camera is the
moving eye of the audience. Unlike the audiences
static placement in the house, the camera is able to view the subject
from any angle. Therefore, you must be sure that the subject is
lit correctly from multiple positions.
When lighting for the camera, some very important points must be
understood. First, it is crucial to realize that the camera is not
as sensitive as your eye. Video equipment sees intensity
and color differently from you and I. In addition, since video is
a two-dimensional medium, people and objects that are not lit correctly
tend to look flat and blend into the background. These concepts
may be basic, but are critical when designing lighting for video.
Although advances in video cameras are producing improved results,
it is still a fact that most moderately priced video equipment will
not see objects clearly in very dim light. This is due to the video
equipments limited dynamic range. This is the term used to
describe the range between the dimmest light the camera can see
without excessive noise, and the brightest light before the object
blooms in a mass of white light. Since video cameras are equipped
with irises, you can always close down the iris to reduce the amount
of light entering the lens. However, if you push the gain or sensitivity
to capture a dim subject, electronic noise is created which reduces
the clarity of the image. The latest digital cameras have extremely
sensitive lenses and low-light capability. However, your margin
for error is reduced greatly at such low lighting levels.
The lighting director must provide a reasonable amount of consistent
light when illuminating the stage for video. This means that the
lighting intensity for the entire area that the subject will be
walking through should not deviate more than 10%. If the lighting
intensity deviates much more than that, then dark holes
will be exaggerated on video as the person walks in and out of these
areas. A good digital light meter is an invaluable tool for this
test.
Although many cameras have auto-irises to compensate for darker
areas, if the iris has to open for a dimmer foreground, then the
background will get brighter too. This inconsistency is certainly
not desirable, especially when dissolving from camera to camera.
In large multi-camera productions, large variables in lighting intensities
will drive the video engineer crazy as the cameras must be continually
adjusted, or shaded, for these inconsistencies.
It is a good idea to keep the background areas illuminated within
30% of the foreground intensity. This is so the cameras irises
dont close too much from a bright foreground object, making
the background too dark. Great care should be given to lighting
to this as good foreground-to-background lighting also helps add
depth.
Another consideration regarding lighting intensity levels is when
you use multiple follow-spots. Extreme care must be taken when two
subjects in separate follow-spots move near each other and the lights
overlap. The lighting intensity will usually double when this happens
and the irises on the cameras must quickly close to compensaterendering
the background darker. The correct technique is to have one follow-spot
fade out as they cross to keep a consistent lighting level. This
is why good spot operators are worth their weight in gold when lighting
for video.
Remember, the camera can only see what the lighting designer illuminates.
The camera may not be able to see dimly lit objects that can otherwise
be seen by the human eye. If you wish the camera to see the audience,
then the audience must be sufficiently lit. The same idea applies
for architectural walls, ceilings, aisles, and entrances.
When planning your lighting cues, it is wise to avoid blackouts
and wide variables of lighting intensities. A lighting blackout
leaves the television screen in total darknessnot nearly as
effective as when you experience a lighting blackout as a live audience
member. Sudden increases in intensities may cause the image to bloom
or become over-saturated with light. If you have many cameras that
are moving around, it may be impossible for the camera operator
to focus on the subject if there is no light available. When shooting
a live show I always call lights up cues a few seconds
early to allow the camera operator a chance to focus before that
camera is cut to.
As video is basically a two-dimensional medium, objects lit just
from the front tend to look flat and blend into the
background. It is imperative that the lighting director help create
the sense of a three-dimensional world. This is partially accomplished
through the use of backlight. This is trickier than it sounds as
the correct intensity, color, and angle of light is critical in
achieving this effect. I suggest that the intensity of the backlight
is at least 50% brighter than the foreground. It is also important
to choose a color that will flatter the hair, skin, and clothes
of the people being lit. Usually a pale color correction of clear
light is used for this effect. This is usually accomplished by adding
a color correction filter to the backlight. Or, if using automated
lighting, you can dial-in the color remotely to highlight
the clothes and hair of the subject.
Regarding angle, the key is to use an angle that highlights the
rim of the hair and the shoulders. If the angle is too high, then
unattractive shadows of the nose, chin, and cheeks appear. If the
angle is too low, then the three-dimensional effect is reduced.
Another good idea is to make sure that the color of the background
offers a good contrast to the foreground. This is why you usually
see a lot of green plants behind pastors. Green is a good contrasting
color to human skin. Avoid colors that incorporate flesh tones as
this causes subjects to blend in with the background.
Another important consideration is how video sees color.
White balancing is the process in which the camera is adjusted for
its relative white color. This is a complex subject that certainly
deserves its own article. However, suffice it to say that
the lighting director must decide what color the relative white
will be and make sure that all the cameras are balanced to it. This
is accomplished by focusing a light with the relative white color
on a perfectly white card that reflects all wavelengths of color.
The cameras are focused on this card and the electronics are adjusted
to treat this color as white. All other colors that the camera sees
are then based on this relative white color.
Color can also be a challenge when mixing arc and incandescent
sources. It is important to understand that the color of an incandescent
light will change as it is dimmed downa situation called amber
drift. This is not true when using arc sources in most automated
lights as the dimming process is mechanical and does not cause the
color to shift. This is another reason why I prefer arc fixtures
for many of my video productions.
Most incandescent lamps have a color temperature of 3,200K, while
arc sources have a color temperature of 5,600K (hence the blue tint
to its clear color). Most automated lighting fixtures
have color correction filters that will balance its source color
to 3,200K to closely match the incandescent sources in your light
plot. You could also color balance your cameras to 5,600K, and color
correct your incandescent sources closer to that temperature if
you want your saturated automated lighting colors to read correctly
on video. I use this technique often on large automated lighting
productions that also use supplemental incandescent sources (for
audience lighting, fill lighting, etc.)
Speaking of audience lighting, I recently worked on the lighting
design at Riverbend Church in Austin, Texas. This church has a large
arched window upstage of the pulpit that allows a huge amount of
natural daylight to flood into the sanctuary. Due to this bold architectural
design, it was necessary to color balance all the interior stage
and audience lighting to 5,600K to better match the daylight. As
the camera angle from upstage past the pastor toward the audience
is a common one used in worship productions, the audience house
lights were also matched to this natural daylight color. We designed
metal-halide arc house-light fixtures with a color temperature of
5,600K to be used for the daytime services. As the church also broadcasts
their evening services, a second system of incandescent house lights
is used. If we did not do this, the video would have the pastor
in one color of light and the color of the congregation would look
totally different.
Finally, when lighting a production for video, figure on spending
most of your time in the control room or video truck watching how
the lighting looks though the monitors. If there is no control room,
then at least look though the camera. This is the only way you can
efficiently and accurately do your job. Remember, when lighting
for video, the eye of the camera is the eye that counts.
David Martin Jacques is a professional lighting designer
and architectural lighting consultant. His lighting designs have
included productions and systems for many churches and theological
events including the Southern Baptist Convention Pastors Conference
in Salt Lake City, Riverbend Church in Austin, Texas, First Baptist
Church of Ft. Lauderdale, and the First Baptist Church of Euless,
Texas. David also heads the Graduate Stage Design Program for California
State University, Long Beach. He can be reached at djacques@csulb.edu.
|