HP Sodium C50S68M vs C50S68/D/M

[Hamilton Felix]

I just pulled the bulb on a 50 watt sodium yard light that's been in use for a few years now. It's clear and marked C50S68/M. I have replacement bulbs available, that are milky white coated and marked C50S68/D/M.

OK, I know they'll run fine on the S68 ballast. Will I really see better color rendition with the same light output?

Mostly, I just want it to last. But I'm curious.

 

[Hamilton Felix]

Never mind. I found a good S68 ballast at work, and fired up a C50S68/D/M bulb. The white coating maybe helps a bit over the clear C50S68/M bulb, but it's still pretty darned "orange." And I'm not just saying that because I was next to a "cool white" fluorescent fixture and in a generator hall lit with mercury vapor lights while I was testing it.

Oh well. HPS is HPS.