Ever noticed that and LED flashlight seems to not be that bright until you look into it, at which point it nearly blinds you? You can take a comparable bulb flashlight and it seems to illuminate your path much better yet you can still look into the bulb (probably not a good idea at all) and focus your eyes on the filament. This has been my observation anyway, maybe some would not agree. I was wondering if that has something to do with wavelength or focus. Would it be possible to get the same performance from an LED as I can get from a bulb? I'm thinking NO, or else LED flashlights already wouldn't suck.

 

It is mainly the size differences. The bulb has a long tightly coiled wire with a large surface area, when compared to the, almost, point source size of the LED element. Comparable lumens but spread out in one form and concentrated to a pinpoint in another.

 

The quality of these things varies enormously. There are a lot of cheap-and-nasty little lights on sale, and in some cases the LED life is nothing like as long as it is claimed to be. The types which connect three AAA cells directly to a few white LEDs seem particularly suspect.

The better ones do put out more light than their tungsten equivalents, at least in small and medium sizes. Something like a 1W Cree LED will beat a 1W tungsten bulb quite conclusively. There are also some pretty good portable lamps (as opposed to flash-lights), typically using several dozen smaller LEDs. These seem to be a viable alternative to small fluorescents, and of course can be considerably more robust.

What possibly is not yet available is a good replacement for the more powerful parabolic reflector lanterns. The lens optics used with LEDs so far do not seem to be able to give such a concentrated long-range beam.