While doing some research on the lighting used in Japan, I have discovered this interesting technical report that discusses the characteristics of Mitsubishi’s 90 CRI BOC quartz metal halide lamps, deluxe high pressure sodium retrofit lamps, and energy saving mercury vapor lamps from about 1983. If you can’t understand the Japanese, you can use Google Translate to reveal some interesting information:

https://www.giho.mitsubishielectric.co.jp/giho/pdf/1983/8302.pdf