IES Photometric file accuracy

  • When you import an IES photometric file for a light fixture, just above the IES file selection Enscape enacts the Luminous Intensity slider to adjust candlepower. How do you know if the photometric file is actually being rendered correctly if you can adjust the candlepower slider to an arbitrary number? Is Enscape determining that the initial candlepower number that comes up IS the actual IES file as tested by the manufacturer? I would think you would just "dim" the fixture down from "full power" for different output levels, rather than change a candlepower value that falls ambiguously on a sliding scale. You have to write down that candlepower value in case you change it and need to return to the tested value. That could be disastrous for an accurate calculation. Thanks in advance for any help.

  • Hey michaeldnoon , the luminous intensity configuration which comes included in any IES file, is currently not being used by Enscape, since the light receives gets a separate adjustable brightness which overwrites that.

    The ability to use the original luminous intensity of the IES file directly would be a logical feature request. I'll gladly file it accordingly, just let me know if you want to add anything further to it? :)

  • Then my question remains; what is the baseline lumen / candlepower performance when I select an IES file and Enscape renders the output? How do I know if it is remotely close to the actual fixture performance?

  • Ok. So when I load an IES file, the Luminous Intensity slider opens with 1,000 cd value in the middle of the slider, but that value doesn't really mean anything. It's an arbitrary number in the middle of the sliding scale. The fixture is opened at the highest value provided in the IES file, BUT I can actually slide up or down from there and make it brighter than supplied by the factory? I guess seeing a candela value was confusing me. It's really just a slider where the IES file's max candlepower value is reflected as the middle of the slider, not defaulted all the way to the right. Correct?

  • Hey michaeldnoon , as mentioned by Simon, the profile itself of the IES file is used, but for the luminosity of the brightest part, the value of the slider is being used instead. In this case, it is set to 1,000 cd by default when you first open an IES light, and you're free to adjust this value afterward. I hope this helps, let me know in case something is still unclear to you. :)