Everything I had to produce light produced a lot of light. One time, Kartographer put on an article by Selco and he spoke of the need for very little light. That really hit me for I had nothing that produced just a bit of light.
Selco said he had need of a tiny light so he could go outside at night without being spotted by the bad guys. Remember he was in a town of active fighting. If he needed to get something that was outside or needed to go father away from the house for something, he didn't want to be spotted and killed on the spot.
I went to Amazon right then and bought penlights, the kind medical people use to check eyes. I had one of those in my medical bag that was many years old and didn't function anymore. The ones I got have a pressure point and you can press that for the light to come and immediately release your finger and the light is off.
If I went into my back yard at night, I would only need to press that button one time quickly to know where I was. I know where objects are back there, I would just need to get oriented quickly to where I was. If I needed to press it again quickly, it would be fast. That tiny amount of light would be hard to be seen very far away.
So, in thinking about bright lights, don't forget practically no light is important, too.
An example of an excellent survival light is a Fenix LD12, it is a small single AA light suitable for the belt, or pocket, yet it is regulated and it has four brightness settings and readily accepts filters and diffusers designed for it, such as red filters, or diffusers to turn it into a lamp.
The LD12 has a low setting of 3 lumens and it will deliver that for 97 hours, it also has a high setting of 120 lumens for a couple of hours, with settings in between such as 27 lumens for 11 hours.
If you want something tinier, then the Fenix LD01 uses a single aaa, is perfect for the key chain and will deliver 3 lumens for 27 hours, 26 lumens for 3 hours, and 72 lumens for 1.5 hours, it is brighter than the old 2D Maglites.
Thanks for the reminder to look at the flip side of light, which is to be minimalist!
On the upper range of lighting.... I have a generator, pure carbon 3/8" rods, and a 30" parabolic reflector. Some assembly required, but I could make an arc-light suitable for shooting down Zeros if I was required to.
Nothing like having a good scrap pile.
/johnny