Last time i was at the thrift shop, i grabbed a Calex GU10 CFL spotlight and it is just hilariously bad.

Why? You're looking at the tops of the U-bends of the discharge tube. The 'reflector' is cylindrical so most light just gets bounced around the cylinder. It runs extremely hot, you cannot touch the thing after it's been running for 15 minutes. The internal reflector is a piece of aluminium so almost all heat emitted by the discharge tube just gets sent right back into itself. The rest of the housing is plastic.
It draws 9w of power and puts out a claimed 190lm, so the efficiency is essentially on par with some of the better halogen spotlights. Yet it claims to offer 80% energy savings.

So what are your worst ones, that you keep around just because they're so awful?

Another one worth a mention here is a self ballasted blacklight MV lamp. I'll dig that one up later and post it. Very sloppy construction, mediocre output.

Wow, that is an efficiency nightmare.

My pick is probably my purple Diazotype reprographic 400W MH lamp (my profile picture). Don't get me wrong, it does look cool when lit, that is why I chose it as my profile picture. But there are a few reasons I am not exactly a fan of it:

- First HID lamp I ever got, looks 100% normal, was expecting it to be normal/usable
- Light output is not usable, may or may not contain harmful UV (nobody seems to know)
- Cycles on it's appropriate ballast (even though arc tube looks pretty new), can only be run up nicely with added CWA capacitance
- BT-37 takes up a lot of my space, and I don't ever even take it out of the box anymore
- Even if it did work right and wasn't harmful, the hour rating of these kinds of lamps is apparently crud anyway

Honestly if I could magically wake up and have this lamp transformed into a normal 400W MH, that would be great. It is just a waste of my space. But I am not gonna just throw it away because they aren't super common, maybe some day someone will give it a loving home lol.

1. Suralux 10w tube and 15w tube. On the 10w tube they forgot to dip the electrodes in emission coating, so it doesn't start on electronic. On the 15w tube, they made it the wrong size (F14T8 instead of F15T8) and they got the phosphor color to be 5000k though it's labelled 6500k.

2. Madhab neon flicker flame lamp. I have no issue with the glass part of the lamp, it's the base. Its made of cheap bright flashy plastic, and the B22 pins are plastic too. The B22 contacts are just screws. It just looks too hideous. A metal B22 base with ceramic filling would look 10 times better.

3. Philips 15w blue glazed incandescent. Blue glaze is a very dim color, not suitable for a low wattage like 15w. Hence, the lamp is half as bright as a small led, and consumes 15w. The other 15w incandescents like green, yellow and red are brighter than the blue one. I don't understand why they didn't use translucent blue lacquer instead of blue glaze.

4. Mysore 160w SBMV. They used the design from philips, who made a flawed design. They placed the starting electrode too close to the main electrode, which meant mercury would short the electrodes resulting in the lamp shutting off after 10 secs. The lamp had to be run at a 45 angle to even function.

These are just non-LED lamps. I have had many brand new led lamps just burn out minutes after they were turned on. Like this led bulb and this led strip.


Worst fixture I made is putting 6x 18w led spotlights of different colors in a 250w HID fixture. The hideous fixture is here.
There was also an idol frame that had leds on it, but it's power supply was horrendous and dangerous.

It is hard to beat the cheapest LED lamps from Ebay of the mid 2010s off the top of the list....

I had a friend who was all into buying that sort of stuff just for entertainment. (Had, he was an old guy and not too healthy, and passed away since)

When the lamps died (with the series string of LEDs going open circuit, which leads to electrolytic cap charging to full line voltage, going past its voltage rating and blowing up with smoke), we would get out the soldering iron and blob some solder over the dead LED to keep the lamp going for another couple days. (Soldering iron also straight from China, ungrounded plug, makes the LEDs on the PCB light up as you are soldering them. Sitting in Lotus position in the plastic chair helped reduce risk of electric shock)



Excluding them, it is still hard to beat many other LED lamps off the top of the list. I'll summarize this with a quote from a salesperson of Z&S, an importer of cheap lamps. (Context : Was his answer when i asked why a LED panel light they sell does not have a lifetime hour rating on the box, but only some ridiculous number in years with small print)

"Our LED lamps are the highest quality, such that their lifetime is measured in years and not in hours"



Of non LED lamps, i'd say most 4-6-8W T5's sold in stores nowadays, and a few 15W and 18W T8's

They have virtually no emitter on one or both cathodes. They appear to be either slightly rectifying, or even "rectifying" on both electrodes (ie. formally not rectifying, but running with abnormal crest factor) from the first start. They may start flashing like EOL randomly while running. They are flashing a lot when starting

Connecting such lamp with a shorted starter reveals that the electrode filaments may be different from each other or even shorted - One lights, one doesn't or they are of different brightness by a few times



Of older lamps, it's a tie between...

CFLs of the early 00's which keep burning up the circuit (scorching hot, no light, no cathode glow) many days or weeks after they EOL'd. Ballast case plastic crushes to dust in hand when trying to remove the lamp from the socket

Festoon incandescent lamps which paint coat goes up in smoke after the lamp heats up (not EOL)

Incandescent lamps with the wires in the cap twisted (short circuit) from the factory

Incandescent lamps which cement is loose from the factory (during screwing the lamp into the socket)

Circlines that work normally once, have no vacuum (or poisoned ?) when switched on 2nd time next day. Replace with new one and same thing happens again

Starters stuck new from the factory

Starters which bimetal presses the glow lamp wall from inside and pops it open after a few uses

Starters which bimetal is broken and just lays loose inside the lamp. Those catch fire when put into use

SON-T lamp with E40 base which doesn't go into most E40 sockets (it's not E39 either, it's something incorrectly shaped not compatible with any of them)