Osram (UK) 150w SON-DL E Deluxe

Two NOS British-made 150w deluxe high pressure sodium lamps.
SON-DL lamps run at higher temperature and pressure than regular SON lamps and therefore have a cooler colour temperature and greatly increased colour rendering.
Efficiency is sacrificed as the lamp has a slightly lower luminous output compared with regular SON.

2300k
20,000h
12,500lm
65% CRI

I used one of these in a home-made uplighter made from an old lowbay luminaire :) In use during the photo as you can see in the reflection :)