Question
"I generated a ray file using ProSource 5.2 and inserted a source into TracePro. Everything looks reasonable, I just have a question regarding units: The ProSource file shows a peak intensity of 0.26 Candela while TracePro gives 0.24 W/sr as the peak intensity on the Iso-Candela plot. If I remember my photometry correctly a Candela is a Lumen/sr where 680 Lumens at 555nm = 1 Watt. Are the ""Candelas"" used by ProSource given in ""Lumen/sr"" or ""W/sr""?"
Synopsis
Changing File Source units between Radiometric and Photometric
Solution
In this case, the ray file was defined in photometric units, while the default units for a File Source in TracePro are radiometric units. To change the File Source to photometric units, First select the source in the Source Tree, then double-click on it to open the File Source dialog box. Finally, change Units to Photometric and click Modify. You can also change the units for analysis results in TracePro. Select Analysis/Raytrace Options/Options and you can then choose between Radiometric or Photometric Units, so the Intensity results on the Iso-Candela Plot can be displayed either in Watts/steradian (W/sr) or in Candelas (cd) which are lumens/steradian. Please refer to the TracePro User's Manual for a complete description of the Radiometric and Photometric units displayed within TracePro.
