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

I hope for clear weather and some spare time in the evening for TA to measure a proper throw-number :slight_smile:

In older days you could get much higher bins in CW then neutral white tints. This is not the case anymore with the highest or 1 bin lower then highest usually being found all the way down to 4000-5000k.

So now days you really do not gain anything by going with CW in the real world.

People still think that CW produce higher outputs but that is mostly due to the cheap meters we use to measure flashlights. They are biased towards cool white light and will ready CW emitters as higher output as an equal bin NW emitter. This is just a reading error in most cases though, the bins in the data sheet much be correct or they would be sued.

So if you get different readings most of that is just a reading error in the meter.

To the human eye it is the other way around, you can see much better and much further with a NW or even WW emitter in the real world. This is well known, it is the same reason the sky is blue. Blue light is refracted in the air much easier then warmer tones.

So with a cool white LED you will see the beam like a light saber but that causes the intensity to drop much faster and the throw to be reduced in the real world.

Neutral white does not refract as easily so in the real world you can see further.

I have posted before my experiences with this that made me a whole hearted convert to NW.

Yes, with 4 cells it would be about 1.5 years.

The indicator can be turned off, like any e-switch light there is still some drain but it would be less. I think it was around 100ua IIRC for the driver alone? Been awhile.

If you plan on leaving it for a really long time then it is always best to lock out the light. Simply unscrew the tailcap a tad and it will have no drain except the self-discharge of the cells.

With a storm moving through and supposed to linger for the next several days, it doesn’t look good.

Although even without a storm, I live in one of the top 10 (think it is #4 last I checked) most humid cities in the USA. So there is not really such a thing as a dry night around here lol. We consider dry anything under 50% humidity.

Right now it is 50 degrees outside and 61% humidity as an example. Last week it was 90f and 80% humidity so it feels great right now.

That is why my beamshots look so vibrant, it is not a trick of the camera, it really looks like that, the refraction of the light is extreme.

Wow, don’t visit often anymore. So glad I did. I’m at work - and that first post is so long. Could someone fill me in on how to get in on this?

PM, specify short or long? Price is $150 with $14 prepay?

Hi dthrckt, you just got in on this by posting. The price for who join in now is indeed $150, for the group of people who pay $150 it is not clear yet when or even if at all a prepay is needed.

haven’t followed the whole thread - but if you make anything that allows an aspheric to be added to this light I’d definitely be interested in buying that….

Great, thanks! I don’t need this, but how can I NOT buy this…

You are now signed up.

All lights will be the long, 8 cell version.

Payment details are not set. Once production starts and it gets close to buying time you will get a PM telling you all the details. What store to go to and what special code to enter to get the discounted price, etc… We may even need to do a small deposit before that. It’s still not known.

So for now we wait. :smiley:

wait…what?
i though i already make a post after the
[/quote]

i was on mobile when i quote TA post :person_facepalming:

I think i have read that you should discharge and recharge (or was it only recharge?) the batteries atleast once every 3 months or they degrade alittle.
Or is that just a myth?

Wow, at 50% humidity we get nose bleeds from the arid weather. We’re happy at under 70, at the moment it’s 80 degrees at 81 humidity, ant it was 95% humidity an hour ago.

The 223 uA parasitic drain sounds a little high. DEL measured it early on without the LED's and didn't think it was so bad. Big difference is where/how it was measured. If measured at the batteries, than it's 223 uA at ~16.8V, which is very high.

Now I'm curious bout this - wish I could find DEL's notes on it. I know the buck driver configuration has a higher parasitic drain but didn't think it would be ~8X higher.

A Q8 with the LEDs ranges from 130 uA down to 90 uA, depending on the LED resistors, but that's at ~4.2V.

Well, technically I suppose they do degrade a bit since the lifetime of the cells are finite. But do they degrade in a meaningful way in a few months? I doubt it. Some folks on the forum keep multiple sets fully charged and waiting for an earthquake or whatever . I do too, but I’m too new to this to notice degradation in my cells. Maybe those with more “time in” will get back to you.

When I first entered this world I did research into the best way to store cells, and if I remember correctly it was at 1/2 charge, ~3.6-3.7 v, and in the refrigerator and dry. But again, there are folks who store cells fully charged and at room temp’.

The possible storage temperature range for Lithium-Ion batteries is is –20°C to 60°C but for prolonged storage period –20°C to 25°C is recommended and 15°C is ideal.

Cells should be stored with a partial charge of between 30% and 50%.

CW has the higher readings, but you can see with NW further. The simple ANSI formula is for vacuum. In real live you have other loses.

The blue light scatters more in the air. At dawn you see only red sunlight. The blue part is filtered out.
At a few hundred metres an object is more washed out with a CW than a NW because of scattering.

Sth. 1km away the light must travel 2km. At these distances NW should be a better choice. And 5000K is quite white.
It would be interesting to see two GTs one with 4000k and one with 5000K LED side by side. In different weather conditions.

IIRC DB customs or Texas Ace has a story with a CW and higher readings on the lux meter as the NW. But the NW was in real life clearer to see.
NW cuts also better trough fog and mist.

One Question and One request:

What colour temperature will the emmiter be?

Also, can anybody with a GT post a picture with it next to the Q8, just so I can have a rough idea of how they compare in terms of size?

Thanks !

Aluminium is extremely forgiving regarding cutting parameters (chip thickness, feed speed etc…) if you are willing to sacrifice a bit of machining time to surface finish the part you can have incredibly smooth surface finish with AL on a lathe, they could very easily do a reflector on wich you couldn’t detect any imperfection with naked eye or fingers , but that would be at the very least twice the machining time (would require a change of cutting tool and slow finish pass).

Hello, please put me down for 1. Thank you

Aargh. I was trying to save some money. Dang you guys.

Screw it, I’m in. Sign me up please.