Blender Guru - Did you know that Cycles now allows for IES lighting? Download the add-on by Lockal here: http://blenderartists.org/forum/showthread.php?276063-IES-Lamps-to-Cycles It's great for realistic architectural lighting! | Facebook
Using IES Light Profiles in Unreal Engine | Unreal Engine 5.1 Documentation
Utilizing IES lights in Blender and Cycles - Lesterbanks