That’s true. So instead think about an almost perfectly flat mirror which still reflects the die of the LED. Maybe it collects the light between –89 and –90 degrees.
The whole mirror is yellow but it’s only collecting 0.001% of the light from the LED.
I think that makes it pretty clear that simply the diameter of the reflector does not tell the whole story.
There is plenty of good information in that thread you linked, I would suggest you go read it and maybe understand that there is a lot more to a reflector than just diameter.
My wife’s father passed away on Wednesday, actually my wife’s birthday. We drove 12 hours to her home town for the funeral, then 12 hours back. Left at 4AM Friday morning and got home at 3AM Sunday morning. A whole lot of 85mph cruising! (And I was getting PASSED! Quite a lot!)
Yeah, it’s another task to get a nice beam profile to go along with the tight hot spot. Once in a while there’s a reflector that will give a light spill with a defined hot spot and it’s truly special. Other’s can have an aura around the less defined hot spot and then more pronounced spill, this is a useful 3 way combination in a general purpose light. The softer spill is most desirable where throw is concerned to keep from being so blinding in the foreground.
Again, wrong…
Just because you can see the yellow of the LED die in the reflector does not mean that it is being useful.
As you can see from the emittance graphs from an LED, the closer you get to –90 degrees the less intense the light is.
If your reflector only picks up a few degrees of light, then it is only reflecting a small amount of photons forwards. The rest goes to spill.
All chip LEDs are like this, just go look at the cree datasheets.
Yes, most of the light would be spill. But the peak beam intensity would still be as one would expect from the relation I=LA. The light intensity from the LED at close to 90 degrees is small, but the luminance is still the same.
???
Where the heck did you decide that?
If your 100mm reflector only picks up few thousand photons emitted between 89 and 90 degrees from your LED, that beam is NOT going to throw very far…
However, if the 100mm reflector actually has more depth to it to pick up between –40 and –90 for example, then you have a light like the TN42 which can throw over a kilometer.
This is simple logic here…why is this so hard for people to understand?
Using a shallow reflector that only gets hit by a few photons does not magically amplify those photons and turn it into a 1km beam of light.
Decide what? I’m just attempting to explain the contents of the above linked thread to you (poorly I guess).
I’m not suggesting to use your extreme example of a shallow reflector. It would of course not make a good flashlight beam and that is why deeper reflectors are used. But the relation I=LA still holds. That is the takeaway message from that thread. Nothing is being amplified; the beam from this shallow reflector you propose would be very narrow since it doesn’t collect most of the photos.
It would not be narrow………it would be 100mm diameter…
The difference is that it would have less intensity because the reflector is only picking up the few photons that the LED emits between 89 and 90 degrees.
The full reflector is lit up by the LED, but lit up dimly because the LED barely emits any light at those angles.
I’m just going to stop replying now because it seems like the concept of “less light hitting reflector = less light focused forward by reflector” is far too difficult for people to comprehend.
This thread has been derailed enough, please go back to talking about battery tubes and what LED to use and whatever.
And when Dale speaks I tend to listen so the last three (dang one can’t just sleep and do some IRL stuff anymore without having several pages to catch up with ) pages can be boiled down to:
MCD might not be able yet the GT will be a heck of a thrower anyway!
Dale, your
made me chuckle.
Enderman, yoir input is nice and plentiful, please don’t stop, the reflector is the core of this baby
And it is very good to talk about it.
I so hope that sweet US reflector that is made in China can be used it being nice and deep
Gonna send a pm about it.
Anything over the TN42 was the initial goal, right?
Yes the 1000kcd would be primo but I’m certain just getting the title of “TN42 BEATER” will send shockwaves through ThruNite HQ. Even 800kcd will make TN think twice.
When the BLF GT beats the 42 it’ll open the manufacturer of the GT (and BLF) up to huge exposure.
I personally feel if the target is the fabled million, we are possibly setting up for failure, and prolonging a process that could take many more months. Looking at the Q8 thread, that was started in April and I think and that’s probably still a way off.
We all want different things in this light - but we all want one thing - TN42 beating performance.
Initial goal was 1Mcd. Even the name proposition was BLF MCD. And beating the TN42 is very easy and doable. The TN is not even a contender in this range, the GT is bigger, better, way more powerful and far-far cheaper. TN could have made something similar, but they want to milk the public with gradient increases in reflector size. That is why the GT is such a big deal. It will push the dormant manufacturers to move things along. Just like the Bugatti Veyron did it to cars.
Everyone was milking the 400-500 horsepower range. And suddenly 1000hp (1mcd=1000kcd) was the talk of the day. Ferrari was upping the engines with 5-20 horsepower per generation, and suddenly after the veyron they release 170hp stronger engine. They could have made it, but there was no competition. That is this BLF MCD GT. To show that they are sleeping, and need to wake up. Push reflector size, push led current, provide results. TN42 is nothing special, anyone from this forum could have put together, it has nothing special. Just a bit bigger reflector than the other competition. Why did the Courui made so much dust, it was a great host with big reflector. And There are at least 30 documented mods on it on this very forum! Drastic improvements with people pushing as big a reflector as they could find. The TN42 made the same those mods, put XHP35HI in it, and jacked up the price sky high!
We all had 30cm spotlights before leds come about, and I still have one. It throws amazingly, over 2mcd. And with 200w hid, it will go perhaps 5mcd. And we are strugglign with the “best” thrower of 700mcd, and i have in the attic a 2-5mcd monster just sitting there waiting to be surpassed for 15 years.
I feel you on the incremental increases and being an exotic car nut I dig your analogy 110%. I certainly would love to see the 1000kcd as we all would there just seems to be a debate on whether the 12cm reflector will do it. Do you personally think it can???
Here is the courui D01 moded from 340 to 625kcd with 86mm bezel and a deep reflector. From the default one. 13cm bezel should power through 1mcd with ease. The main problem for me is the surface brightness of the led. Here the xpg2 is used with fet. It can even be improved with buck driving up to 5.5A and provide more throw. Dedomed also. Then we go to the Xplhi, which is larger and smaller (?) brightness. Then we go to the XHP35hi which is even larger and even dimmer!
I am sure that most modifications (and the first ones) will be with swapping the emitter for an XPG2 and improving throw compared to XHP35hi about two-fold.
If the tn42 provides 700cd, with XHP35hi, then with larger, and more importantly deeper reflector, and a bit more current in the led, it should easily achieve 1mcd. With XPL even more, and with 5.5A XPG2 dedomed, a whole lot more than 1mcd. The mod above in the thread will tell you the improvements of a deeper reflector.
Regarding the manufacturer of the lovely IM reflector, could it be Nata?
A bit of detective work led me to this idea:
The smaller xml10 reflector Here is exactly the same as the Cutter xml10r Here The manufacturer is listed as Nata on the Cutter site and the image is the same on both IM and Cutter pages.
Might be worth someone with the language skills that I lack contacting Nata?
As you can see, the 3cm extra reflector diameter makes a LOT of difference, it almost doubles the total output. (theoretically).
Suppose we use the 120mm, use an ar-coated lens and the light intensity is 120Cd per mm2, we can calculate:
(120/2 - 10/2)² * 3.1416 * 120 * 0.85 * 0.96 = 931
Suppose the reflector is of very good quality, we could calculate as follows:
(120/2 - 10/2)² * 3.1416 * 120 * 0.90 * 0.96 = 985
What it boils down to - in order to reacht the infamous 1Mcd:
maximum voltage to the led - so optimal heatsinking- and dissapation
) pages can be boiled down to: