ITT/American Electric ballast. They had this choke style ballast with aluminum windings in the 70's, 80's and 90s.

Verdeons actually are discontinued now.

I’m not sure either. Not sure if this helps, but I have been using Ecosmart lamps as of late, though they are just regular ones, most being 2700K, one 3000K, and two 5000K.

I have a 2700K snowcone from 2020 that is has just about five years of use in a table lamp, used about three hours a day, but after that generation they made them even lighter, which I don’t like. They still had weight then that gave somewhat of an assurance on how quality would be but now they feel light as a feather unfortunately. I have two other snowcones in use, a 2700K in a closet light (installed in 2023 I think), and 5000K in a garage light (installed in 2022 I think) and those have been working good.

Their filament lamps have been good to me as well. I know you said you tried them but I’m not sure if you tried the ones I used (regular ones). I have some 2700K 60w (closet light) and 100w equivs (floor lamp) installed in December of 2023 and they have been going strong no issues. Along with a 100w equiv 3000K (installed in mid 2023 I believe, room light) and a pair of 5000K versions (outside lights that are D2D, Oct 2023 and Aug 2025). The October 2023 one is a notable one as before that, I was installing Feit filament LEDs and literally the longest I got one of those in those outside lights was a year and a half, no joke, and started getting those in 2018 (dumb I know).

As @HomeBrewLamps says, sourcing older LED lamps might be your way to go. I have 2700K 65w equiv GE BR30s and Feit BR30s from 2018 (kitchen), another from 2021 (kitchen sink), and Feit G25 40w and Great Value 40w equiv (2018, most of the GVs had failed over the years except two, bathroom), and the best ones, a pair of Feit Electric 85w equiv BR30s in 5000K, that have run D2D since January 2019 with no issues. I haven’t had failures from the lamps mentioned above except for the GVs. The only mass failures I had were with the Feit A19 60w and 100w equiv filament LEDs. The longest I got from one of those was I think three years, in a garage opener light out of all places. People trash on Feit but I have great experiences with some of their older LED lamps.

Home Depot is closer to where I live so that’s been where I’ve been getting my LED lamps lol. Can’t say anything about the other brands.

I am sure many of you are aware of the miniaturizations of MH lamps. Commonly available down to 20W and 15W, with prototypes being made down to 3w or maybe even lower (I think I remember seeing a 2w one here but I can't remember).

Recently while browsing Trad Lighting, I came across this post from Max detailing a 15W SON lamp, designed for use with 20W fluorescent chokes. This is very interesting, as I haven't ever heard of HPS below 35W before. As far as I am aware this is the smallest HPS lamp ever made, though feel free to prove me wrong, I would love to hear about it.

That leaves MV behind. The smallest MV lamp I have seen is the North American 40W H45 lamp whish isn't even that small. I would assume that any attempts to miniaturize it would be for scientific/microscopy applications rather than general lighting due to the poor efficiency. Has anyone heard of MV lamps under 40W? Any experimental designs?

@Medved
While yes these sockets were installed on 32A circuits, each socket itself was only rated to carry 13A maximum (the largest fuse that could be safely installed in a plug).

And yes I am making a lot of assumptions here. Assuming the plug has a fuse, assuming the pins are shrouded, assuming the socket is shuttered, etc. Assuming all of those conditions are true, this system is safe. But there is no way to ensure that, which is admittedly a problem.

@Michael
Type J seems relatively similar to others like H, K, N, and O. Often no safety shutters or fuses in the plugs. Which is usually not as much of a problem since the maximum circuit size is 23A (but more often just 16A), but the conductors in the cords seem to not reflect that, just like the US. At least they have shrouded pins, that is definitely a good thing.

Interesting note on three phase compatibility, I did not know that. I can see how that can be useful.

Problem is, the "screw in bulb" is maybe the most LED-hostile format in existence. Rather high intensity on small space, light emission in all directions, means there is not much space where to dissipate the heat. Filament concept works well, but only limited power, like up to 8W for really largeR SIZE bulb. And only when the fixture really allows free cooling air movement around the bulb, so open fixtures only.
With enclosed fixtures the limit is at about 4W, so we are at barely 600lm with the most efficient LEDs on the market (the power figure includes the driver losses), so not that much of light output.

Way better performance you get from purpose built LED lanterns (assume decent design and build quality, so likely not the cheapest trash on the market), but these tend to use propriatery parts, so hard to fix once fails, so you need a completely new lantern.
So more of a "creating a new installation", not a "what to put into existing fixture" thing.

The problem is, in theory you can capture any color accurately (if you usa a sensor that has exactly the same spectral response of its channels like the eye), but you can never display all colors accurately, it is mathemathically impossible without an ability to really accurately form any arbitrary spectrum.
In real life common standadrs rely on 3 channels (R, G, B; or their recalculated equivalents like YUV or so), so not enough information to form all colors correctly. So the system needs some compromise. It is optimized so at least most natural and common colors are displayed correctly (skin tones, nature,...).
The drawback is for certain spectrums the color distortion becomes quite significant, an example being the typical mercury radiation spectrum.
So you can in theory tune the system to display the mercury radiation correctly, but then it will suck for other colors, like e.g. skin color tones (notoriously hard to display, as people are especially sensitive on any error there, yet normally of way higher priority for correct display than back alley mercury lamp).

Plus if you take into account what was the historical driving force for picture capturing (the movie industry), the scary looking greenish hue quite matches the mood of the scenes where this lighting uses to prevail, so such color distortion becomes more a feature than a bug...

I think our Swiss type J is the best. Bescause it’s small, safe and in some cases the 230V plug (T12 or T23) can be plugged into a 230/400V socket (T15 AND T25)

https://en.wikipedia.org/wiki/SN_441011

Well, "simple appliances" (that is how the standard here used to call such devices; like hot melt glue guns, cloth irons,...) don't need switches, they can be controlled just by unplugging them. If done too frequently in one socket, you wear it down at it loses connection sooner or later regardless what mains socket standard we are talking about. Having a switched socket prevents that from happening, but on the other hand the switch itself presents more wear prone parts of the installation.

And for the British mains socket/plugs: Weren't they originally designed to work in 25A or even 32A circuits? So their design needed to anticipate at least 32A upstream fusing. Therefore the need for such beefy construction and the secondary fuse within the plug, as the 32A fuse won't be able to protect the cable from the plug to the device (or the cable would have to be too thick to be practical).

Most (practically all not based on the British one) other standards limit the maximum fuse (breaker) rating for domestic circuits to just 10..16A, so the branch fusing becomes sufficient for practical cable sizes without any need for any in-plug fuse. And allows the sockets/plugs to be way more compact.

So when judging safety, I won't agree the with the statement of the British system to be "the safest", when relying no moron would replace the blown fuse in the plug for a nail or so. With standards from everywhere else the cable is just protected by the breaker in the panel.
Yes, at the time of its origin, the power limitation the other systems impose semed as impractical, at that time the need was to quickly reduce the use of local coal burning stoves and convince people to use electric heaters instead, therefore the need for the rather high power sockets in homes.
Other parts of the world did notface that problem, so did not need such high power capable mains socket system, so went for simpler and more compact solutions.

But if you look on any modern wiring, there use to be way more branches than would be needed if the power rating would be the limit. So no need for 25 or 32A capable socket anymore, then the British standard (of such oversized sockets/plugs) becomes more of a historical relic than anything useful. But as with any other such standard, once set, extremely hard to change, even when others may be way better suited for present day needs.

You could hunt for bulk NOS lamps on ebay. Otherwise I am not sure.