Tempered glass for MH lens...

[sphelps]

Originally Posted by mr.wilson

HQI lamps have a UV filtering quartz outer glass, so you don't need to have a quartz glass lens. You needed a quartz lens with the old Osram Powerstar lamps.

I was under the impression the HQI or DE bulbs don't have the UV filtering outer glass and require tempered "low emissivity" glass. It's the Mogul or SE bulbs which have the UV filtering outer glass and don't require any additional requirements for a glass shield.