Jason are you saying if the reflector size and shape was different by “x” amount here or there then it would have a bearing on where exactly the emitter should sit in order to achieve maximum performance ?
When someone designs a reflector, they have to choose a focal point for the emitter. The shape of the reflector is based on this focal point. If you look at the picture I posted earlier and look at the red lines, those lines represent a focused beam going straight out and if you follow those back they will always converge on a single focal point.
Scannerguy tested the BLF GT at BLF GT Worlds Farthest Throw LED Flashlight - YouTube. Calculated throwing distance of 1776,28 meter. Measured 49300 lux at 4 meters.
Does anyone know the exact LED bin or the color temp of it ?
That’s quite intriguing. So, let’s just imagine someone plans to mod the MF04 with an expensive CFT-90 emitter, probably a LED with another die size, it’s not just a matter of changing the LED and driver but also a matter of the right alignment of the LED in the reflector? The CFT-90 is supposed to make a larger spot on the BLF GT as far as I have learned. Besides that, I’m curious what kind of alternative emitters might be suitable for the MF04….like OBF or CFT-90.
4 meters are not far enough. I think his calculation is not really reliable.
The CFT-90 is 3mm2 compared to Cree xhp35-HI at 2.35mm2.
Yes, Vinh has to get the emitter and reflector lined up on all 3 axis. Same with OBF. Getting it centered left and right is the easy part because you can see it with your eyes. Finding the proper depth requires experimentation.
As far as other emitters are concerned, it just depends on what you’re looking for. If you want even more distance you can go with an XP-G2 or Olsen black flat. It goes further, but it’s a small hot spot and less lumens.
Or you can go with a bigger emitter like xhp50.2 or 70.2. Distance goes down, but you get a bigger hotspot and more lumens.
The reason the CFT-90 has a bigger hotspot yet can equal or exceed the distance of the xhp35hi is due to it’s higher efficacy. It puts out more light per cubic mm than anything else.
All of this applies for any light, not just the MF04…
Does it make sense to say lights should be designed with the intention of the emitter sitting flush with bottom of the reflector to achieve the best possible beam? The reason I ask is because with the emitter being recessed it seems like some of those precious photons (or lumens) otherwise are being bounced around between the emitter and the bottom of the reflector rather than being focused out the front?
Only about 50% of the emitters light is hitting the reflector anyway, so loosing a little at the bottom is not any big deal.
Order placed, thanks freeme.
Mr McLumen, have you seen my L6 reflector? I cut the bottom out of it so I could experiment with emitter depths.
I thought you might find it neat.
That is interesting Jason . I would think there are an “infinite number of angles” so to speak as the light hits the sides of the reflector with a longer reflector length having more angles that a short one.I do realize some of the light shoots straight out the lense and doesn’t contact the reflector. With light companies “playing the numbers game” I would guess high priority is given to perfect emitter location in relation to reflector. Lol, if it is not it certainly should be
Saw that Pic Jason. Looks like something I might do depending on how expensive the light is.
The L6 is about $60 or so.
The SMO reflector is about $7 plus shipping, so no big deal.
Check out this article for more on reflectors.
Neutral white emitter option added after short discussion. 
CW - Cool White ( product ID: 1289449 )
NW - Neutral White (product ID: 1296763 )
What about those who already pre-ordered the MF04? Do those people still have a choice between CW and NW and if not, which version is going to be delivered if neither CW nor NW was mentioned in the product description?
Looks like MF04 can Lego with MF02.
Perhaps banggood should sell the head for those already have MF02.
I won’t be willing to buy the whole light as I already have BLF GT 
It does. MF01 is also compatible. Same with MT18, MT35 and MT35+.
What he said,inquiring minds need to know
What is your product number, the first one listed was the CW, #1289449.
CW – Cool White ( product ID: 1289449 )
NW – Neutral White (product ID: 1296763 )