AGi32 positions luminaire photometry with respect to the counterclockwise from East (CCE) system approved and published by the IES in document LM-72-97. All four aiming angles can be applied sequentially to any luminaire and are (in order): Orient, Tilt, Roll, Spin.
The CCE system states that with all four angles equal to zero, the luminaire's zero-degree plane of photometry is pointing due East. All subsequently applied angles are positive when rotated in a counterclockwise direction following the right-hand rule.
The Procedures tab describes the Orient, Tilt, Roll and Spin aiming processes. It refers to Global and Local axes. The Global axes don't change; they are the axes that represent the luminaire's environment. The Local axes are affixed to the luminaire. When the luminaire is reoriented, its axes rotate with it.
It cannot be over emphasized that when aiming luminaires, you must have knowledge of the luminaire distribution and how it is represented by the photometric file. Manufacturer and testing laboratory alike have exercised a fair amount of liberty when testing luminaires photometrically. Alignment of the luminaire on the testing apparatus can vary for similar luminaires when tested by different laboratories. This essentially changes the location of the zero-degree plane of photometry with respect to the luminaire. Needless to say, an incorrect assumption can render all computations performed by AGi32 inaccurate.
Loading any file into our Photometric Toolbox program will allow you to examine the luminaire's distribution via its polar curve and offers the easiest way to visualize the light distribution. A knowledge of the LM-63-95 document (IES format for photometry) is also extremely valuable.
Application of the aiming angles
AGi32 allows the Orient and Tilt angles to be easily adjusted using the mouse when locating or modifying a luminaire. Using the Locate and Orient option from the Luminaire Define Toolbar will allow you to adjust the luminaire Orient angle by simply moving the mouse in the direction you would like to point the zero-degree plane of photometry. Using the Locate and Aim option, both the Orient and Tilt angles are adjusted when moving the mouse to an aiming-point location.
Applying Roll and Spin to a luminaire can only be done by entering the angle value in the appropriate cell on the Luminaire Define Toolbar; it cannot be adjusted using the mouse. Orient and Tilt can, of course, be applied from the toolbar as well. However, the Static Aiming option should be employed when specifying Orient and Tilt on the toolbar. Using Locate and Orient or Locate and Aim will adjust the angle values.
The four aiming angles are always applied in succession, beginning with Orient, followed by Tilt, then Roll, and finally Spin. Thus, when visualizing a combination of aiming angles, always apply them in order.
Note that all luminaire positions are possible by applying a combination of three aiming angles. The ability to use four aiming angles is simply for ease of operation. Please note that it is also possible to manipulate luminaire position beyond what is possible with conventional mounting hardware!
TIP: In AGi32, you can turn on the Photometric Web (in the Luminaire toolkit) to help with aiming! You will be able to see a three-dimensional representation of the luminaire's candela distribution, which can help tremendously when aiming a luminaire.