The majority of lighting fixture manufacturers are currently employing the IESNA standard recommended file format for luminaire photometry. The most current standard is (IESNA document LM-63-2002, although much photometric data is presented in various older versions of the standard).
The ASCII file format is shown below. This is exactly how any IES format file should appear when listed directly from a text editor. The standard for this format is included in the lighting method documentation LM-63-2002 available through IESNA.
Each line marked with an asterisk must begin a new line. Descriptions enclosed by the brackets"<" and ">" refer to the actual data stored on that line. Lines marked with an "at sign" @ appear only if TILT=INCLUDE.
All data is in standard ASCII format.
*IESNA:LM-63-2002
*<keyword [TEST]>
*<keyword [TESTLAB]>
*<keyword [ISSUEDATE]>
*<keyword [MANUFAC]>
*<keyword 5>
"
*<keyword n>
*TILT=<filespec> or INCLUDE or NONE
@ *<lamp to luminaire geometry>
@ *<# of pairs of angles and multiplying factors>
@ *<angles>
@ *<multiplying factors>
*<# lamps><lumens/lamp><multiplier> <# vertical angles>
<# horizontal angles><photometric type><units type>
<width><length><height>
*<ballast factor><ballast lamp factor><input watts>
*<vertical angles>
*<horizontal angles>
*<candela values for all vertical angles at first horizontal angle>
*<candela values for all vertical angles at second horizontal angle>
* "
* "
<candela values for all vertical angles at last horizontal angle>
NOTE: At the time of release of this publication some luminaire manufacturers do not employ the IESNA:LM-63-2002 keyword scheme. Photometric Toolbox does not require the IESNA:LM-63-2002 keywords, however, the Instabase uses keywords if present. Without keywords, all information preceding the TILT= line is read as descriptive information.