What short arc for maxabeam-like searchlight?

[Enderman]

OMG THE LEGEND IS BACK!
Holy crap I thought you were gone forever since your original account had been inactive for years...
I have to say, thank you so much for all the inspiration

 

[Ra54]

Thankyou for the warm words Enderman.
Greta is hopefully going to restore my original account.
I noticed that i have a lot of reading to do here, lots of new stuff after being away for so long.

 

[Enderman]

Haha I'm pretty new here too, but I've been lurking and reading topics from this forum for years when researching about flashlight stuff.

 

[Ra]

I'm back with my original account, thanks to Greta..Now the fun can restart.
I notice that i need to grab me a new avatar, well, I will do that the coming days..

Edit.. No.. I apparently don't need to, but why didn't it show in my profile settings? Weird.. well never mind.

 

[Enderman]

Woo!

Also, Polarli, I actually got a reply back from Scheiderwerk, they seem like they will cooperate, now I'm waiting for them to tell me the cost and confirm the HBO103W/2 will work.

While I save up to build this crazy HID thrower, I'm working on my aspheric thrower
I have almost reached 1.5M cd! If I am correct, this would be the longest throw distance LED flashlight ever made?

 

[PolarLi]

That's pretty nice LED numbers you got there! In fact, nice numbers for anything called a flashlight. What lens diameter are we talking about here?

 

[Enderman]

100mm, cheap lens from fasttech, I haven't found any better ones...even though I have tried like 20 others...

The only way I have managed to exceed it is using a dual lens system with one 70mm aspheric + huge 10" spherical lens from a theater spotlight, and I got over 2M lux with that.
But there is no way I consider a 10" cylinder that weighs like 20kg a "flashlight"
There was someone else that made a topic on this forum about a 2M lux led light using this same dual-lens system, also with a huge 10" lens.

That's why I still think that the 100mm light I am working on is still the farthest throwing "LED flashlight" in the world.
If something can't be held in one hand and easily pointed around, then it's not a flashlight
Also the reason why I mention "LED", there are plenty of HID throwers that get way more than 1.5Mcd.

 

[The_Driver]

While I save up to build this crazy HID thrower, I'm working on my aspheric thrower
I have almost reached 1.5M cd! If I am correct, this would be the longest throw distance LED flashlight ever made?

Sorry, but somebody has already built one with substantially higher Candela values here. He uses a de-domed XM-L2 (a lot of potential improvement there), a Wavien collar and a very large asperic lens to get over 3 Million Candela.

This is a very interesting thread though .

@Ra: great to have you back! Some much has happened in the last few years (concerning LED technology). Maybe you can also check out the German TLF forum (and blf forum). We have some dutch members and a lot of custom LED throwers have been built in the last few years. Just recently the 1 Million Candela mark was reached with a single LED in a medium sized reflector.

 

[Enderman]

Sorry, but somebody has already built one with substantially higher Candela values here. He uses a de-domed XM-L2 (a lot of potential improvement there), a Wavien collar and a very large asperic lens to get over 3 Million Candela.

I can't see anything on that website? Is a login required or something? It's in some other language...

 

[The_Driver]

I can't see anything on that website? Is a login required or something? It's in some other language...

It's the German flashlight forum (you need to register to see some things). Here are some (older) pictures of the light.
Here is a beamshot comparison. The last light at the bottom of the page is the one we are talking about.

You can beat the light if you use a Cree Xp-G2 LED or a Osram Black Flat Gen 2 LED (highest luminance you can get currently) and a Wavien Collar.

 

[Enderman]

It's the German flashlight forum (you need to register to see some things). Here are some (older) pictures of the light.
Here is a beamshot comparison. The last light at the bottom of the page is the one we are talking about.

You can beat the light if you use a Cree Xp-G2 LED or a Osram Black Flat Gen 2 LED (highest luminance you can get currently) and a Wavien Collar.

Oh that one! Yeah I remember seeing pics of that a long time ago when researching LED flashlights
I just googled it again, these are the specs: de-domed XM-L2, aspheric lens diameter = 208mm, 2.366.823 lux

Based on the size, I would not classify this as a "flashlight", just like I wouldn't classify my 10" (254mm) cylinder as a flashlight.
I could probably get 3 or 4M+ lux out of that, if I got 2M lux with crappy focusing, no wavien collar, and an XP-G2 at 3A.
But that's a project for a later time!
If a 208mm lens would count as a flashlight, then my 254mm lens should too, since it is less than 50mm bigger.

Based on the pictures of the photon mod, it doesn't look like a "flashlight" either, it is just the lens mounted to an aluminum stand with the LED in it?
Not sure because I can't see any pics of the full or finished light on google images.

I guess it really depends on the subjective definition of a flashlight though...

 

[The_Driver]

The collar was added later, No pics yet. Now over 3Mcd, you can believe me. He is just the first guy to combine the collar with such a big lens. I know the man personally.

Scheinwerfer means spotlight in German. I consider everything a flashlight as long as it has no cable and can be carried.

 

[Enderman]

The collar was added later, No pics yet. Now over 3Mcd, you can believe me. He is just the first guy to combine the collar with such a big lens. I know the man personally.

Scheinwerfer means spotlight in German. I consider everything a flashlight as long as it has no cable and can be carried.

So in your opinion a hellfighter 4 is not a flashlight because it has a cable?
Anyway, the definition of a flashlight is subjective I guess.

Do you have any pics of the photon mod finished?
The only pics I can see of it are just a head with the lens sitting on an aluminum stand, no battery or flashlight body or anything.

 

[The_Driver]

So in your opinion a hellfighter 4 is not a flashlight because it has a cable?
Anyway, the definition of a flashlight is subjective I guess.

In my opinion: yes, but who cares .
Calling it a flashlight or not doesn't really change anything.

Do you have any pics of the photon mod finished?
The only pics I can see of it are just a head with the lens sitting on an aluminum stand, no battery or flashlight body or anything.

Not really, maybe someone took some at one of the local meets we had here (Photon has attended some of them).

I think the batteries are mounted at the back. It's a very crude design. He just built it because he found the optic at some ham-radio flea market (apparantly all kinds of random stuff is sold there).

Concerning the topic of the thread:
Please keep in mind the high amounts of uv radition that the HBO puts out. Ra talks about this in his thread. It's very dangerous and can also degrade some materials inside the light if it isn't constructed properly.

 

[Enderman]

In my opinion: yes, but who cares .
Calling it a flashlight or not doesn't really change anything.

Not really, maybe someone took some at one of the local meets we had here (Photon has attended some of them).

I think the batteries are mounted at the back. It's a very crude design. He just built it because he found the optic at some ham-radio flea market (apparantly all kinds of random stuff is sold there).

Concerning the topic of the thread:
Please keep in mind the high amounts of uv radition that the HBO puts out. Ra talks about this in his thread. It's very dangerous and can also degrade some materials inside the light if it isn't constructed properly.

Ok, well I guess I can settle for longest throw led flashlight in the 100mm class then
Or build a 4Mcd thrower with the 10" lens I have and call it a flashlight.

Also, I double checked the definition of a flashlight, and it says anything portable, so technically I could still use an external battery inside a backpack or briefcase and it would still be a flashlight
Just no cable that goes to wall power or stuff like that.

Would the UV degrade the interior of a rhodium coated reflector?
Do I need to go with silver or aluminum or something like that?
There will be a UV filter on the front of course.

 

[The_Driver]

Ok, well I guess I can settle for longest throw led flashlight in the 100mm class then
Or build a 4Mcd thrower with the 10" lens I have and call it a flashlight.

Do you by any chance have a Wavien Collar? It makes all the differance (it doubles the luminance of small LEDs in combination with aspheric lenses).

Also, I double checked the definition of a flashlight, and it says anything portable, so technically I could still use an external battery inside a backpack or briefcase and it would still be a flashlight
Just no cable that goes to wall power or stuff like that.

Would the UV degrade the interior of a rhodium coated reflector?
Do I need to go with silver or aluminum or something like that?
There will be a UV filter on the front of course.

No, rhodium is used precisley for this reason - it's very robust. Optically it's not as good as other coatings (only 75% reflectance in the visible spectrum).
Aluminium is the most fragile coating (it will degrade under UV), but the cheapest one with high reflectance (90% reflectance in the visible spectrum).
There are coatings like "enhanced rhodium" which are the best of both worlds. There are more expensive though (as are large mirrors in general).

If you want to use a cable to power your light - go ahead. Nobody will stop you. I wouldn't worry so much about that.

 

[Enderman]

Do you by any chance have a Wavien Collar? It makes all the differance (it doubles the luminance of small LEDs in combination with aspheric lenses).

No, rhodium is used precisley for this reason - it's very robust. Optically it's not as good as other coatings (only 75% reflectance in the visible spectrum).
Aluminium is the most fragile coating (it will degrade under UV), but the cheapest one with high reflectance (90% reflectance in the visible spectrum).
There are coatings like "enhanced rhodium" which are the best of both worlds. There are more expensive though (as are large mirrors in general).

If you want to use a cable to power your light - go ahead. Nobody will stop you. I wouldn't worry so much about that.

1) yeah I have a collar, that's what boosted me from 900k lux to 1.46m lux

2) cool, now I know, rhodium it is

3) For a handheld one like my throw LED one probably not, but for this HID one I definitely will, I just build a nice tiny battery supply inside a pelican 1120 with a really nice cable and connector.
Battery case in one hand (or backpack) and flashlight in the other will help relieve weight from one arm for long carrying sessions

4) I just got an email back from Schiederwerk, apparently they only mass produce their ballasts when they get an order for many of them from a company, and it isn't cost efficient for them to build only one.
I guess I could have asked them to add 1 unit for me to the next company that orders a bulk order, but I doubt it would end up below $500 anyway so it's easier to stick with the HBX76 which Ra already confirmed works great.

5) I just realized I've been calculating lux and cd wrong this whole time, and my numbers don't really mean anything because the farther I take my measurement, the more cd I get.
http://www.candlepowerforums.com/vb...ula-for-calculating-throw-using-aspheric-lens
I should be using this instead: http://nightsword.com/uniformbeamcalc/

I tested this with a small aspheric flashlight, I got 12000 lux at 1m which is 12000cd, but 4500 lux at 2m which is 18000cd.
A point source of light should be 3000 lux at 2m because of the 1/r^2 equation.

Maybe if I took my measurements at 100m I would get 10 million cd? xD
I will take some longer distance measurements soon and measure the diameter of the spot so I can calculate the TRUE candela / candlepower/ lux at 1m / whatever you want to call it

 

[The_Driver]

If you tell me some specifics of your light I can calculate you your candela.
The two most important things are the diameter of the optic/reflector and the luminance of the light source (for LEDs I can help you with this, a guy in the German forum has measured this for many LEDs).
I can then calculate the Candela rating of the brightest part of the beam.

If you want a more precise calculation I need to know more specifics, like if your lens is coated, how you heatsinked your LED etc.

 

[Enderman]

If you tell me some specifics of your light I can calculate you your candela.
The two most important things are the diameter of the optic/reflector and the luminance of the light source (for LEDs I can help you with this, a guy in the German forum has measured this for many LEDs).
I can then calculate the Candela rating of the brightest part of the beam.

If you want a more precise calculation I need to know more specifics, like if your lens is coated, how you heatsinked your LED etc.

Well the LED is 1.45mm x 1.45mm, which is 2.1025mm^2 and produces 1000-1200lm, so that is 475.62 to 570.75 lumens/mm^2
However 1 lumen = 1cd per steradian, so idk how you would get the cd/mm^2 from that ^

The lens is uncoated borsilicate glass, and the LED is on a fan cooled CPU heatsink that keeps it at less than 40C under full load.

I think the most accurate way of measuring the true candlepower would just be measuring the size of the spot at 50m or something like that, then easily finding how far behind the lens the rays converge with simple trig.

Thanks for the help though!

 

[PolarLi]

The UV degradation of aluminium quartz coatings is slow. You will have several hundreds hours of burntime before noticable degradation occurs.
In other words, several lamp changes.
Just make sure you keep the reflector below 250F. That's atleast the information I got from Phoenix.

As for UV, regular soda lime glass block everything below approx 320 nm. Borosilicate go down to 290-300 nm.
You can check the glass datasheets for more details. Either way, you are basically left with the same type of UV you get from the sun, mostly UVA, and a little bit of UVB depending on the Ozone layer.
But still, it ain't a toy, and it can burn you more than one way so to speak.