technical Issues capturing the art of motion
The art of concert dance
documentation, like all arts, requires dedication to technical training.
Effective documentation requires proficiency with features of the video
camera, as well as mastery of camera movement involving sensitivity, coordination,
and control. Below is a list of technical issues, followed by techniques/recommendations
for improving performance behind the camera.
Issue
– Focus
Clarity of image is essential in producing high quality documentation products.
Accomplishing this requires clearly focused recordings that simulate the
experience of live performance viewed with the details of 20/20 vision.
One issue, quite unique to dance performance, is that the subject area for
documentation is typically a large-scale surface containing movement simultaneously
in the foreground and background. Keeping the entire depth of the stage
in focus throughout a dance, or evening of dances, is no easy task. This
can be especially problematic for follow shots that encounter a constantly
changing distance between lens and subject. Maintaining sharp focus involves
familiarity with a number of camera features, as well as an understanding
of depth of field (DOF).

Focus Point 1/3 Distance into the Performance Space
Techniques/Recommendations
We’ve probably all witnessed poorly documented dance that included
blurring, breathing focus each time a dancer passed in the foreground of
the shot. Because of the ever-changing spatial arrangements in dance it
is recommended that manual focus be used for documentation purposes. This
involves locking in the most ideal focus and preventing the camera from
thinking for itself. When defining a focus it is important to understand
that there will be only one distance from the lens that is in perfect focus,
and all other points are gradually less focused the further they are form
this point.
The range of distances from the camera at which acceptably sharp focus can
be obtained is known as depth of field (DOF). Areas outside this range are
often referred to as being in Soft Focus. DOF will tend to extend 1/3 in
front of the focus point, and 2/3 behind it. This fact determines the placement
of a focus card as 1/3 of the distance into the dancing area of the stage.
A focus card placed at this location should include a high contrast, hard-edged
image that the camera can easily use for focusing. This card may also include
a large white area for use in white balance. See White Balance below.
DOF is basically determined by the iris setting: the smaller the iris aperture,
the greater the depth of field. This means that the more light you have
on stage, the easier it is to focus. Unfortunately, abundant light is rarely
the case in concert dance performances. In very low-light situations where
the iris is open wide, depth of field is significantly reduced and focus
becomes quite a challenge.
Factors which influence depth of field:
- Lighting conditions
- Camera filter
- Shutter
- Gain
- Lens angle (zoom)
The more DOF you have,
the easier it is to maintain focus. If you need more DOF, you can:
- Add more light.
- Move the camera closer to the stage, therefore closer to the lighting
source.
- Add some digital gain, although this compromises picture quality.
- Reduce shutter speed, although not recommended for fast moving images,
like dance.
This excerpt from Salon
by Nancy Smith Fichter poses the challenge of documenting a duet which
includes a variety of depths.
Based on the idea that sharp focus is determined by defining a focal point
at a specified distance from the lens, it must be true that any point along
an arc at that distance will also be in focus. One technique I have used
for resetting a focus during a pause in performance involves the use of
a predetermined point in the theater, equal in distance from the camera
as the ideal focal point located 1/3 of the distance into the stage. As
the house lights briefly illuminate the theater for the audience to see
their programs one can zoom in on this predetermined spot, reset a focus,
zoom out, and pan back to the stage with a newly confirmed focal distance.
This is especially useful if the focus ring is accidentally bumped during
performance.

The Focal Arc
Some cameras have focus limitations related to color of light. Lighting
designs containing a large degree of red may result in a “bleeding”
image that appears out of focus. Also, the use of haze and smoke on the
stage can present challenges for sharp focus. One may want to discuss these
issues when designing lights to determine if priority should be given to
lighting that videotape well.
Basic steps for setting focus:
- Determine placement of tripod and camera. This establishes
one of the coordinates used to determine
distance between camera and focal point.
- Set camera in Manual Focus Mode.
- Place a focus card at a depth 1/3 of the distance into
the performance space.
- Zoom in as tightly as possible to the focal point.
- Press and hold the Auto Focus button, or temporarily
place camera in Auto Focus Mode until image
comes into focus. This defines the second coordinate used to determine
focal distance. Return camera to Manual Mode to lock in focus.
- Zoom out
- Repeat this sequence if camera placement is modified.
Moving the camera alters distance between
lens and focal point and can change DOF.
With all the video production resources available on the web, I would never
attempt to reinvent the wheel. Here are but a few of the links I have found
to be useful:
Depth of Field
http://www.mediacollege.com/video/camera/focus/depth-of-field.html
http://www.dvinfo.net/articles/optics/dofskinny.php
http://www.luminous-landscape.com/tutorials/understanding-series/dof.shtml
http://journalism.berkeley.edu/multimedia/tutorials/shooting_tips/depthfield.html

Blurred and Overexposed
Documentation
Issue
– Exposure
White blobs of washed out dancers with no apparent detail, sound familiar?
What about faintly lit silhouettes and shadows hardly distinguishable as
moving bodies? Whether overexposed or underexposed, documentation footage
may be improved by controlling the amount of light entering the camera.
Footage shot of a brightly lit stage recorded without monitoring the excess
light allowed into the camera is an irreversible tragedy. Even the best
editors in the world cannot magically bring back the lost detail of costumes,
faces, and subtle gestures. Add this problem to the frequent lighting changes
within a dance and one is faced with many challenges when videotaping concert
dance. The human eye has a much greater value range than the camera and
therefore requires constant attention to exposure. See Lighting in the Aesthetic
Issues section for more details.

White costumes and projections,
two very challenging elements, are combined here in Blank on Blank
by Alwin Nikolais.
Techniques/Recommendations
Whether shooting in live performance or during a session specifically for
documentation, a number of related techniques may be applied to improve
video quality. In both situations, it is important to develop a partnership
with the lighting designer. Manual exposure is always recommended. When
shooting during live performance it is recommended that the initial cue
for a dance be predetermined, so the videographer is able to anticipate
the first look on the stage. From here the task of compensating for light
changes on the stage is up to the videographer standing by with their thumb
on the iris wheel. In an ideal situation, all videographers would be on
headsets and would be given warnings prior to lighting changes. If time
permitted, a cue list including iris settings could be created for each
lighting change. In the situation of a video shoot for documentation a brighter
lighting cue is recommended, which will allow for a higher shutter speed,
more closed iris, and no gain. The combination of these will allow for control
of exposure, while increasing the DOF. Some cameras have a Zebra Stripe
function that provides visual evidence of overexposed areas within the viewfinder.
This function may be set to depict different percentages of washout. This
can be very useful when manually monitoring iris settings during a shoot.
Unfortunately, it is not always possible to have this feature appear on
an external monitor.

Resident Videographer Peter Richards conducts a white balance with his video
intern at Bates Dance Festival.
Issue
– White
Balance
Accuracy of color on video is an issue worthy of attention. We’ve
probably all wondered why costume colors or skin tones seem to have been
mysteriously modified by some form of hue adjustment. This problem is similar
to that of adjusting the tint on your television monitor. This issue becomes
even more problematic in stage performances due to the use of colored gels
on the lighting instruments. White Balance, joins Focus and Exposure to
become “The Big Three” technical issues that can most drastically
improve or destroy video footage for dance documentation.

Comparison of Accurate
and Inaccurate Colors Based on White Balance Settings
Techniques/Recommendations
Overcoming the problem of inaccurate color representation involves conducting
a white balance prior to each video session. The purpose of a white balance
is simply to define true white for the camera. Once this is accomplished,
the camera will see all colors in relation to the defined white. Without
getting into great detail, cameras see colors differently depending on the
temperature of the lighting source. Since different types of lights have
different temperatures (incandescent, halogen, fluorescent, sunlight), it
is necessary to set the white balance whenever there is a change in lighting
source.

Conducting a white balance involves the use of a white balance card, basically
any truly white surface that the camera can use as a representation of white.
A medium intensity lighting cue containing no colored gels should be used
to create a neutral light situation. Gain should be eliminated. Set the
camera’s white balance feature in Manual Mode. Zoom in to fill as
much of the frame as possible with white and adjust the iris to prevent
overexposure. Press and hold the white balance button until camera adjusts
to display white as white. Lock in this setting for the duration of the
shoot. As gels are added to the lights, colors should appropriately be represented
on video. Most cameras retain their last white balance setting as long as
they are not unplugged from the power source, or have a charged battery.



White balance determines the accuracy of colors on stage in works such as
these by Alwin Nikolais.
Issue
– Camera Movement
Virtuosic performance
behind the camera involves both the development of kinetic awareness and
complete understanding of the nuts and bolts of movement potential within
the camera itself and through the extended movement capabilities made available
through the use of a tripod. Camera movement along the X, Y, and Z axis
allows for an infinite number of choreographed combinations. An expertly
trained dance videographer appreciates the ways in which motion on various
planes may add meaning or impact to subjects in the eye of the camera. Such
partnering with the camera requires manual zooming skills and a developed
sense of pressure and resistance with the camera. In general, camera movement
for documentation should never draw attention to itself, but should flow
in accord with choreographic intent.
Techniques/Recommendations
Prior to beginning a documentation session videographers must finely tune
their tripods, including setting the sensitivity, or resistance, for panning
and tilting. Tensions should be determined as to allow for smooth initiations
and controlled movements in all directions. One must become comfortable
with a grip on the camera that allows for delicately pressing the camera
into motion, coordinated with the body’s shifts of weight. One hand
may be primarily assigned to the zoom ring for adjusting depth on the Z
axis, while the other hand counterbalances the camera from the other side.
Care should be taken when gripping and releasing the camera, as the smallest
bump of the camera can be detected on video. Similar techniques and sensitivity
to motion apply when utilizing a handheld technique without a tripod.

Video Intern at Work
at Jacob's Pillow Dance
More information related to camera movement may be found in the Spatial
Intent in the Aesthetic Issues section.
Contribute
to this list of issues and techniques/recommendations by contacting
DanceDocumentation.com, or
by visiting the Dance
Documentation Blog.