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April 2005
Why Use Robotic Cameras?
By Richard van Pelt
Before committing to a robotic camera system many questions must be answered. One of the first questions is "What advantages does a robotic camera system offer over manual camera operation?"
First, there is only a single operator required to position and control all of the cameras. This is in contrast to manual operation, which requires each camera to have a dedicated operator. Often additional personnel are required to direct the shoot. This savings in manpower is often motivation enough to commit to a robotic camera system.
Second, robotic cameras are less intrusive than manually operated cameras. Robotic cameras are installed in non-intrusive locations, which do not distract from the service. Typical locations include robotics discreetly mounted on walls, at the rear of the church, under balconies or tastefully behind the pulpit. Manually operated cameras require the operator to be visible to the congregation and can detract from the message of the service.
Third, robotic cameras have the ability to go to preset positions. A preset position is a pan, tilt, zoom and focus setting stored in the robotic system. When commanded, the robotic camera will automatically go to this preset position with the simple press of a button. Most robotic systems have 8 to 16 preset positions per robotic camera position. Typical shots stored as presets include pulpit close-ups, wide shots of the congregation, choir shots or special event shots. Manually operated cameras do not have preset capability.
Control Room of Briarwood Presbyterian Church
James Hulgan, the video director of the Briarwood Presbyterian Church uses such a robotic system. "Briarwood Presbyterian Church in Birmingham, Alabama uses the ESI 180 robotic controller to operate 4 cameras in our worship center. Services in the Worship Center are video taped using four robotic controlled cameras. These cameras are smaller than traditional broadcast cameras and are less distracting to the congregation since they do not have an operator standing behind the camera. When we videotape dramas or ballets, they often have total blackouts on the stage. With 16 presets per head, we are able to pan, tilt, zoom and focus each to its assigned point on the stage with all of the lights out. That is almost impossible to do in the dark without presets. The other advantage for us is that I can operate 4 cameras, and switch the show live by myself. This is a huge cost savings when I don't have to hire 4 camera operators."
Less manpower, non-intrusive cameras and presets are only three of the reasons robotic camera systems are becoming more and more prevalent in today's church services.
How do I define a robotic camera system?
Once the decision is made to use robotic cameras, many new questions arise. How many cameras do I need? Where do I put them? These are only a couple of the questions that must be answered when designing a robotic camera system. To determine the number of robotic cameras, analyze the worship center for specific areas to be included as video shots. Typical worship center shots include the pulpit, choir, organist, soloist, baptismal, stage and congregation. Determine how many camera angles are desired for each of the worship center shots. This will also help to locate the robotic camera mounting locations. The drawing below illustrates typical robotic camera locations.
Of the seven camera locations shown, usually only 2 to 4 cameras are used for a church service. The most common four camera configuration is camera locations 1, 3, 4 and 6.
When designing the robotic camera layout, be careful of a couple of common pitfalls. One of my favorites is a shaky balcony. Balconies provide ideal locations for mounting robotic cameras but the balcony must be stable. A shaky balcony has motion that will result in a camera shot with undesired motion.
Ideally all camera locations will be virtually invisible to the congregation. Be careful not to pick a camera mounting location that will get the congregations attention and distract from the service.
Selecting the Ideal Robotic Camera Lens
There is a variety of camera and lens combinations used in robotic camera applications. These include camcorders, single CCD cameras with C-mount lens and 3 CCD cameras with bayonet or C mount lenses. While all of these are viable offerings, the most common camera and lens combination used in robotic camera systems is a quarter inch 3 CCD camera with a bayonet mount teleconferencing lens. These cameras have an inherent low light capability and the lens selections available are ideal for church applications. Further, teleconferencing lenses have zoom and focus presets necessary for church robotic camera applications. There are two dominant manufacturers of these teleconferencing lenses: Fujinon and Canon. Typical lenses from the two manufactures are presented in the table below:
As shown in the table above, there are a variety of lenses available to be used in robotic camera applications. When selecting a lens, be sure the wide and narrow fields of view encompass the desired areas of coverage. Shot selections requiring close-ups are normally head and shoulder shots with an area of coverage of a maximum of four by six feet. Wide shots that include the choir or congregation must have a wide enough area of coverage to easily accommodate the subject. The table below illustrates the areas of coverage for several popular teleconferencing lenses.
To use the area of coverage table, pick a focal length within the zoom range of the lens you have selected and note the area of coverage for the distances from 50 feet to 150 feet. For example, An S16x7.3BMD lens has a minimum focal length of 7.3 mm. This is approximately half way between the 5 and 10 mm entries. Therefore at a distance of 100 feet, the area of coverage at the minimum zoom position yields approximately 96 feet in horizontal by 72 feet in vertical.
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