Thanks, folks... I'd decided the common claim of "aircraft grade" aluminium given for low-end torches was (usually) specious, but didn't know about "LED fade," nor thought about switch quality. I realise you get what you pay for, but as you can often buy 10
cheapies for the cost of one
high-end torch, it becomes harder to decide what's the better deal.
I hadn't thought about hand-cranked torches either, but having one around would clearly be a good idea. They're widely available in the UK, but look very low-end. I checked both Brinkmann and Garrity on Amazon UK; the former look the same price as other top brands, and Amazon don't offer Garrity hand-cranked models.
To light up a room, I have a fluorescent camping lantern that takes 4*D batteries, but it only really gives enough light to see your way around, not enough to actually do
anything. Fluorescent tube lanterns have also been superseded by LED lanterns, but look quite large. I've seen a recommendation for the pen-sized RIL50 8 LED Mini Inspection Light
. It doesn't really look big enough to light a whole room, but good for working in small areas, like vehicle engine compartments.
An expensive recommendation I saw recently, and that appealed to me, was for the LED Lenser V2 Aviator Torch
because it has a ring of white LEDs surrounding a single separately-switchable red LED. The idea is to use the latter for things where you don't want to affect your night vision, like map-reading, but to have full illumination readily available as well.
LED torches are making my old incandescent Petzl head torch look decidedly dim, so maybe I'll start looking at head torches again. Sigh...
I think skwire's right about LED light quality. It may be something to do with the output not being full-spectrum, just a narrow band of frequencies. I've even seen that stated as a reason why they can't be used for hunting at night, the lack of full-colour vision also spoiling one's depth/distance perception.