[PART 1] Official BLF GT Group Buy thread. Group buy officially closed! Lights shipping.

:person_facepalming:
Not surprized, but it makes no difference; ‘thijsco19’ was gracious enough to provide a simple, uncomplicated answer.
Thank you, I shall endeavor to move ahead always, hopefully you shall also…. as well as Forever Upward. :+1:
Ahead & Upward…. despite bumps in the road, a great combination. :wink:

“To everyone, if you want to have the gt made please drop this discussion.”

Amen.
Drop the drama and if need be, let the moderaters filter it out.
Let’s stick to the subject and move on.

I’m still in!

Grtz
Nico

I al interested. Count with me for 1

Me too :wink:

Err… drop the conversation??
What’s going on here? I’m totally lost. There has been literally 90% less banter on here for the last 2 weeks, than anytime before.
I’m getting the impression something is going on certain members don’t want us to know about. If the conversation is to be “dropped” why even start a GT thread?
This is BS. All the drama is over, we want answers and updates and now we are being told to not discuss anything?? Bollocks. 100%.

Are you referring to this one:
https://www.fasttech.com/products/1617/10006828/1543306-110mm-aluminum-smooth-smo-reflector

Yes doesn’t that look just awesome!

Thank god. I just wanted to cut the crap before it started all over again.

This is exactly what I ment with ‘drop it’. There is nothing “going on”.

Obviously I was referring to all the drama. Its perfectly fine to talk about the GT. (might be better if I’ve said drop the drama)
All that need to be said from the team is said. There are no updates at this point afaik, all the questions are answered.

I don’t understand how it can be so extremely cheap? Even the smaller ones listed there are more expensive!

So,if there is a order of some hundreds of 120mm mirrors,the asked price would be a bit more expensive and not way expensive.

It looks like instead of machining the reflector they use a technical procedure called deep drawing. Once you have the form the production is be very cheap. My guess is that these reflectors are used in those cheap handheld plastic led “searchlights” where they sell high quantities.

Please add me to the list of interested in gp

So, if your “guess” is correct fritz15; do you think this type of reflector would be suitable for the “GT”?? Or would it just be a cheap compromise that sacrificed preformance?
Any thoughts or guesses at this point?

My guess there is that there is a reason most or basically all flashlights known to me use a reflector which is turned on a lathe. But I really don’t know very much about that so I’m probably the wrong one to ask.

Thank you, I understand; that makes sense to me.
I can’t imagine a reflector priced that cheap having much real value except for use in a crappy light.
But hey, I could be wrong; I’m no highly trained expert either. :wink:

I’m going to guess that it will work with large LEDs, but not will really small ones like XP-G2.

Why??

The bigger led, the more light will be reflected in the “wrong” direction…
But whit a smaller led placed exactly in focalpoint, more lightbeams will go in the right direction for that specific reflector.
And with a mathematical perfect parabola reflector with relatively big measures, the accuracy of installing the led in the focalpoint will determine if it will send the lightbeams in the right direction.

So a smaller led (if we can imagine they have the same output) will be better in this case.

Probably what The_Driver was implying is exactly what you said. Since there is a lower expectation for collimating the beam of a larger LED, the lack of surface quality will be less noticeable than with a smaller LED.

I do hope, and I belive we all know, this flashlight needs e good reflector…so please don’t use a low-quality reflector in this build… :person_facepalming:

In my mind we have to build this flashlight around a pretty high-end reflector…and have the china’s to make the housing for us.
The led we have chosen will do our job, that I’m sure of. :+1:

Then we will (maybe) reach our goal of +–100$ price…maybe.

But what do I know about this… :wink:

(DavidEF and the_driver, I hope we don’t need a bigger led to make up for a low-quality reflector… :wink: )

I said this based my knowledge of spotlights and the experiences from multiple modders, notably Vinz. If the parabola shape of a reflector is not accurate it is impossible to get a small light source in the optimal focus point so that the entire reflector surface is lit up uniformely (which is needed for maximal throw and efficiency). This is why HID spotlights (those with short-arc bulbs) like the Maxabeam (and even the Polarions and XeVisions) use high-precision electroformed reflectors (larger ones cost multiple hundreds of dollars). Short-Arc bulbs have very small arcs (<10mm) and in these arcs most have a very small, much more intense part of the arc. The 75W Xenon bulb of the Maxbeam for example has a 0.3mm hotspot in the arc. The reflector needs to be precise enough to be lit up completely by this small hotspot in the arc if you want maximum throw.
Now, with LEDs this is much easier because they are much larger than the hotspots in the arcs of short-arc bulbs. The XP-G2 for example has a size of 1.6mm^2 to 2mm^2 (depending on how old it is) when de-domed. The XP-L HI with 3.67mm^2 and XHP-35 HI with 5.9mm^2 are already much larger. Still though the XP-G2 (de-domed) and smaller LEDs like the XP-E2 and Osram Black Flat are much smaller than the XHP-35 HI.

Mostly problems arise when large plastic reflectors are used like the one in the Fenix TK-61. I have read a post of someone who had problems getting a de-domed XP-G2 into focus. The XP-L HI worked though.

EDIT: here is a nice example of what I wrote. There are 6 different HID spotlights which all have large reflectors of varying quality. You can ignore the size and actual brightness of each reflector. Just look at how uniformely bright each one is. The last two lights have high-quality reflectors. The Polarion (second from the right) has a electroformed reflector and the light on the right has a glass reflector.
A note regarding the Polarion: because of the position of the light in the picture, the arc was not straight. This causes part of the reflector to be darker in the picture. LED lights don’t have these problems.

EDIT2: this might be interesting for some people here - the brightness of the reflectors in the pictures shows the luminance (“surface brightness”) of the different lightsources. All of the lights except for the last one (last two pictures) have standard automotive HID bulbs. You can see that they are very similar, but the Polarion and the Vector are better because they overdrive the bulbs. The last light has a 120W Philips UHP (ultra high pressure) mercury short arc bulb used in projectors. They have an extremely high luminance. Even though it has a slightly smaller reflector than the Polarion it produces more than 5 times the Candela/Lux. Candela is the product of reflector size and luminace of the light source.