In the last time I've used my Osram HQI-TS 70W/WDL Excellence, which contains thalium-sodium-rare-earths + lithium as an impurity from the quartz, I've noticed it is much dimmer than my Electra rebranded Venture MH-DE 70W/UVS/4K having sodium-scandium chemistry.
I thought the main rare-earth in the Osram lamp is Cerium, but Max think differently.
What are the rare-earths that are used in this lamp? Are they're the usual dysprosium-holmium-thulium?

I thought the main rare-earth in the Osram lamp is Cerium, but Max think differently.

Please don't misquote me. I never said that the lamp does not contain cerium, I only asked you where you got the information that the lamp contains cerium - nothing more than that!

Honestly, beside sodium and thallium, I have no idea what the warm-white HQI-TS Excellence contains. Also, what I know for sure is that if there is cerium, this cannot be the only rare earth element present in the burner as its operating temperature is not high enough to ensure an efficient operation with Ce only, you need a CMH burner for that, and in that case the arc is so contracted that only an electronic ballast will enable a proper lamp operation.

Sorry. I didn't understood you in my thread that you have commented.