Festool syslite KAL II-set

[pingvinlakrits]

For a very simplified distinction between a few of the units:

candela: intensity of a light source (similar to a unit of power like the watt)

lumen: the flux of photons (with an intensity given in candelas) passing through a given solid angle - e.g. a sphere around a candle (lumens = candelas x steradians)

lux: flux of photons passing through a given surface area (lumens per sq. meter)

 

[sae]

Also, there's little correlation between the number of LEDs and the spread/intensity of the light.

Technically you're right, however LEDs by their very nature are more of a pinpoint light than a broad/diffused light.  That's not to say you can't put a diffuser around them (ala LED light bulbs).  LEDs are nice bright, spot lights.  The challenge is to diffuse it properly to get coverage.  Just look at reviews of early (and to this day) LED light bulbs and you'll read about ones with a black spot at the top, where light isn't emitted/diffused from.

Using more LEDs in a unit, appears to make it easier to diffuse.  A good example is CREE's LED bulbs.  They're not using a single LED, they have 80 in there.  They technically have 4 LEDs grouped together into what looks like a first glance 1 LED.
http://www.designingwithleds.com/cree-60w-led-replacement-bulb-review-and-tear-down/

So I guess it would've been better in my make believe example to say better diffused light (like the syslite) lights an area better.  My point was more about lumen vs lux than the technology behind producing LED lights.  In that context a single 5 megawatt LED vs 5 million 1watt LEDs, I'd wager my house that the 5million LEDs have a higher lux rating.

Sorry, but none of this is correct. Even Cree has LED dies that range from sub-90 degree beam patterns to much greater, on a single die, without the use of reflectors or projectors.

The reason for multiple LED dies in a light bulb is for two reasons, efficiency, and heat management. Their most efficient LED dies are nearing 100 lumens per watt, but not in a single die at the output necessary for lighting a room. It's also much easier to manage heat over a larger area with more dies, and doesn't require expensive aluminum heat sinks to dissipate the heat.