Luminaire Define - Metrics Section

 

The Metrics section does not require any input, it is simply a technical display to assist in evaluation of the selected luminaire photometry. There are three unique displays plus a More button that enlarges the two graphs and makes them interactive.

Luminous Intensity Graph

The polar graph of luminous intensity is also known informally as a graph of candela curves. The industry standard display of information for Type C photometry includes the Horizontal Cone through maximum candela (shown in red) and the vertical plane of the horizontal angle containing the maximum candela (in blue). The default display of information can be user controlled using the More button (images below).

This graphical information is often difficult for all but the most seasoned professionals to understand and we encourage you to use the More button to adjust the angles and experiment. Both a Plan view (red) and an elevation view (blue) are plotted on the same graph. The graph represents different angles for each. For a quick lesson see our YouTube video.

Horizontal Cone - This is a conical slice (though it does not look like a cone) viewed looking down from above (Plan view) through the maximum candela value. In the case below this occurs at 60 degrees up from Nadir (Nadir is straight down). That's why it is referred to as conical, it's not flat.

Vertical Plane - This is a graph of candea for each vertical angle measured when sliced through the horizontal plane containing the maximum candela value. In this case it is at 70 degrees H (horizontal). This is an elevation view of that plane.

For a great explanation of the graphs for Type C photometric reports please watch our YouTube video.

Type B Photometry

The candela graph for Type B photometry (specific to floodlight and projection luminaires) is displayed in a Cartesian format which is industry standard for type B data. This displays the axial intensity distribution left to right (H in blue) and bottom to top (V in red). The center beam intensity is in the middle for both graphs. Type B angles range from -90 to +90 in both axial displays. Type B data has no backlight (light behind the luminaire.

The red curve represents a vertical slice through the center of the light distribution from below beam center (left side of graph) to above beam center (right side of graph), (imagine the luminaire is aimed at the horizon). The Blue curve represents a horizontal slice through the center of the light distribution from left to right. Visualize the Red curve as being the vertical beam spread and the blue curve as the horizontal beam spread.

Related Topics

Type B Photometrics

Type C Photometrics

Luminaire Classification System (LCS) Graph

This refers to the Backlight, Uplight and Glare rating system (BUG), as established by the Illuminating Engineering Society (IES) and the International Dark-Sky Association (IDA). BUG is calculated for Type C photometry only. The details of this system are described in the IES document TM-15-11, Luminaire Classification System for Outdoor Luminaires. The LCS system replaces the legacy Cutoff system previously based on relative photometric testing for HID (and other sources) luminaires. The LCS system is based on total lumen output as opposed to lamp lumens and is more suitable for LED sources.

Calculated Metrics

LCS / BUG / LER metrics - Details

Printing from the More dialog

The print button within the More dialog will print a pre-formatted output page with the candela curves you have selected. Included in the output are: the photographic image associated with the selected luminaire (if it exists); your logo or the AGi32 logo (set your logo from the AGi32 File Menu, Banner setting); an echo of the description section from the IES file; the classification as computed by AGi32 and a description of the candela information plotted.