Vintage light bulb

[Mike Watterson]

Our USA friends had an advantage because of lower voltage. Thicker filaments allowed them to get more light output for a given power and life. Eg a 100W, 1000h lamp was 1330lm here, 1600lm there.

I think that's not always true. Or maybe never true. The lumens per watt for tungsten, and the colour temperature, depend on the gas in the bulb, the filament construction and the operating temperature.
Also some 100V - 115V lamps use different construction to 220-240V lamps, apart from the base. Curiously the European ES is supposedly 1mm larger than USA version. I read France and Greece used to use the 22mm BC of UK and all former British Territories.

I note B&Q are selling BC to European ES adaptors. Any comments?

IMO these are the best non-filament lamps yet since CFL and tubes went to Electronic Ballast. ZERO RFI and the decent ones have the best colour rendition I've seen apart from halogen. Don't confuse with Colour temperature.

https://en.wikipedia.org/wiki/LED_filament

They may be longer life due to not having an Electronic PSU/ballast to fail and lower LED temperature?

The lowest power are available with half as much power in USA.