Scalable Camera Selection & Placement Recommendation Guide

Camera Selection & Placement

Camera selection and placement involves a number of inputs, not only technical, but also based on the physical space and end-customer expectations. In many cases, the systems integrator and system designer will have meaningful input in determining which cameras to use and how many are needed.

It is important to consider the aesthetic, function and serviceability requirements of the overall system when finalizing a camera layout. Scalable's software is extremely flexible with camera locations, so prioritize what works best for the customer and installation.

Below is a list of guidelines and recommendations for determining a workable camera configuration, if additional assistance is required. Scalable also offers design services to specify exact locations within a 3D model. Scalable design services and associated requirements can be found at the conclusion of this document

Camera(s) Selection

Camera selection will ultimately determine how many cameras you will need and where those cameras should be located. Scalable Supports a selection of Canon, Logitech, and GigE cameras for calibration. Each offers different advantages and system requirements, summarized below:

GigE Canon Webcam GigE Canon Webcam

Camera(s) Placement

Camera(s) should be placed so that the software can see all display pixels that require calibration. Cameras should have a clear, unobstructed view of the screen or screen section and should not be placed in the light path of the projectors. When physically constrained by the space or the screen geometry, you can use multiple cameras to capture sections of the display. It is important that each camera FOV overlaps at least 1 % with its neighbors‘ images for multi-camera setups,

The camera QTY has no impact on the final results of the calibration, however, adding additional camer-as can add complexity and overall calibration time. As a general rule, you should avoid having more cameras than projectors whenever possible.

If cameras are placed at extreme distances from the display, it is important to ensure the camera has enough resolution to successfully calibrate all screen pixels, The Scalable algorithms are capable of a 5:1 screen-pixel to camera-pixel ratio. A 12mp GigE camera is capable of 60mp on the screen, that's 20 HD projectors with a single camera! The key is to ensure that the FOV is fully utilized, otherwise factor in % camera FOV when calculating the pisel ratio.

For the best calibration results, avoid placing cameras at estreme angles to the screen. If the cameras are placed at acute angles, the calibration patterns can be distorted beyond recognition to the camera(s) which may cause the calibration to fail.

Most accurate results will be achieved with a 3D model. Cameras can be placed in 3D models with the same methods used to place projectors, by moving angular light-cones to cover the screen and avoiding obstructions of the image. Since a 3D file includes the most information to identify obstructions and physical references for mounting, this is the preferred approach for overall accuracy. Using a 2D model is also possible but may require estimations of exact locations due to limited information and uncaptured elements.

See below examples of 2D and 3D files containing the information necessary to properly design camera layouts.

Camera Mounts

Including flexible mounts and pivot arms helps ensure that the cameras will have the freedom of movement to account for real-world deviation from a pre-build design. This gives the most flexibility on-site and reduces risk of a last-minute change or additional camera. Depending on where the camera will be mounted, you may want to consider different camera mounts to adapt to different structures e,g aluminum tubing, 80/20, stage truss etc. When selecting a mount, it's important to account for any ambient vibration in the space to prevent cameras from moving over time.

Scalable always recommends fix-mounted cameras to gain the most value from the auto-calibration and reduce long term maintenance on the system. Below are some examples of different Camera Mounts used on Scalable Projects:

1. Manfrotto 492 Centre Ball Head - ¼” universal screw mount adapter, pivot joint to allow flexible 'aim' of the cameras from a given location - PN: MH492-BHU
   
2. Manfrotto 2-Section Single Articulated Arm w/Camera Bracket - articulating arm to maximize camera movement and adjust camera location (143BKT) - PN:196B-2
   
3. Joby GorillaPod® Magnetic 325 - low cost solution for rapid setup while maintaining aim flexibility - PN: JB01506-BWW
   

Scalable Design Services

Scalable offers design services to assist customers with precise 3D locations within an existing CAD model of the space, Scalable technicians can work with the following 3D file formats¦ .DWG, .DXF,

.STEP, .3DS, .OBJ.

In order to guarantee best possible results, the 3D files should include:

• Screen
• Projector bodies
• Projector light cones
• Objects within the screen volume during calibration that could obstruct the camera view e,g, cockpits, furniture, seating, curtains, design features etc,
• Structural elements around the screen, that may prevent camera placement e,g, trussing, columns, beams, AC ducting, etc,

If you are interested in contracting Scalable design services, please contact your Scalable Sales representative for additional information.