What short arc for maxabeam-like searchlight?

[NoNotAgain]

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

By your definition the Surefire Hellfighter 4 is a flashlight as well as the Hellfighter 5 since both lights have a self contained lithium battery.

Just so happens that you can also use the mil cable to charge as well as operate the light.

The same cable that operates the original Hellfighter light also powers the Polarion Night Reaper light. The Hellfighter 4 requires a different cable since the light has a high/low setting and a strobe function.

As for using a Wavien collar on a short arc tube, I think the temperature of the tube would melt the collar. If a glass collar existed, you'd have to be bug nut on in the placement of the tube for maximum culminated light and not interfere with the arc focus.

 

[Enderman]

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.

Thanks for the info It would be fan cooled, so temps shouldn't be an issue. I always like to go overkill on the cooling.

By your definition the Surefire Hellfighter 4 is a flashlight as well as the Hellfighter 5 since both lights have a self contained lithium battery.

Just so happens that you can also use the mil cable to charge as well as operate the light.

The same cable that operates the original Hellfighter light also powers the Polarion Night Reaper light. The Hellfighter 4 requires a different cable since the light has a high/low setting and a strobe function.

As for using a Wavien collar on a short arc tube, I think the temperature of the tube would melt the collar. If a glass collar existed, you'd have to be bug nut on in the placement of the tube for maximum culminated light and not interfere with the arc focus.

I thought the HF4 didn't have a built in battery unless you get the tube extension thingy? I know the HF5 does.
I don't think anyone mentioned a wavien collar on a short arc light, that is for my other LED flashlight.
The wavien collar is glass though.

 

[PolarLi]

Do not go overkill on the cooling (except it's only on the reflector) To much air flow over the arc chamber on a mercury lamp will give you reduced output.

 

[Enderman]

Do not go overkill on the cooling (except it's only on the reflector) To much air flow over the arc chamber on a mercury lamp will give you reduced output.

Cooling for the reflector I mean, it's easy to make air flow around the outside of the reflector without touching the lamp.
The HBO103 says it should be cooled by convection, so a slow airflow inside the reflector area should be ideal.
It's different for LEDs though, lower temp = higher output, I was considering using liquid cooling for one of my LED projects.

 

[The_Driver]

By your definition the Surefire Hellfighter 4 is a flashlight as well as the Hellfighter 5 since both lights have a self contained lithium battery.

Just so happens that you can also use the mil cable to charge as well as operate the light.

The same cable that operates the original Hellfighter light also powers the Polarion Night Reaper light. The Hellfighter 4 requires a different cable since the light has a high/low setting and a strobe function.

As for using a Wavien collar on a short arc tube, I think the temperature of the tube would melt the collar. If a glass collar existed, you'd have to be bug nut on in the placement of the tube for maximum culminated light and not interfere with the arc focus.

Why are you making a topic of this in this thread? Who cares what anybody defines as a flashlight for his or herself? It doesn't matter.

When we were talking about the Wavien collar, we were talking about Endermans LED spotlight.

Using such a mirror with a short-arc bulb can be done, but then it's called a retro-reflector. It serves a completely different purpose though in that case. A retro-reflector collects more light, making the spot and corona of spotlight bigger and eliminating the spill.

The Wavien colar for LEDS reflects wasted light back onto an LED where it is reconverted to a light of different Wavelength (mainly blue light to yellow-green light) and exits the LED at different angle and then hits the lens. It is basically an increase in luminance.

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!

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

Ok, lets talk about calculating Candela/lux. It much easier than you think.
I will show you a formula for calculating maximum center-beam Lux for any light with a lightsource and a reflector or optic. All you need is the diameter of the reflector/optic and the luminance of the light source.
Lets use your 100mm lens and a Cree XP-G2 as an example. Luminance values for the XP-G2 can be found in different threads in the German TLF Forum (sorry, no English, just use google translate). Here you can find a luminance values of many different LEDS (measured) and many other lightsources. TLF-member sma is an expert on this subject and has gone to painstaking effort to measure theses values as accurately as possible for him. You can see there that a Cree XP-G2 R5 mounted on copper "DTP" PCB will reach a maximum of 200cd/mm^2 under ideal conditions. The problem with this LED is that Cree increased the size of the DIE twice last year (see here). The larger the DIE, the smaller the luminance (unless there are much more lumens emitted from the larger DIE). The old R5 and S2 LEDs had the small DIE. Then came the S3 and S4 Bins which probably were one size larger. Later on Cree made the DIE bigger again. This is the size of the current S4-binned XP-G2s (and the luminance is probably not as high as before). Here is a measurement of a larger S4-binned emitter, probably the medium sized DIE. It's still quite good. Now wee want to find out how the luminance changes with the Wavien colar. sma also studied and measured this here (he used an old-style XP-G2 S2 and all three collar sizes). Generally at the maximum possible current and perfect focussing (very difficult with the Wavien collar) you can expect up to 2.2x the luminance (which is amazing). He measured 470cd/mm^2 @ 6A. I will use this value for my calculation.
Imagine that you are looking at the optic your light from where the hotspot would be. From this perspective the reflector/optic looks like a flat circle. We now need to calculate the area of the circle that is lit up by the LED (the part that is yellow). For a 100mm diameter lens, this is (50mm)^2*pi = 7854mm^2. Now all you have to do is multiply this with the luminance of your LED and subtract some losses.

Luminous intensity = luminance * surface_area_of_optic * losses_lens_transmission * losses_because_of_heat
= 470cd/mm^2 * 7854mm^2 * 0.92 * 0.95
= 3226266cd = 3.23Mcd

So if there are no substantial problems with your light and you are using a "good" XP-G2 @ 6A with an optimally placed collar and the 100mm fasttech lens is lit up completely by the LED, you should be getting 3 Million Candela.

Details on the formula I used can be found here. The well known DrJones might also have an English explanation on his website, but I am not able to open it.

 

[Mr. Tone]

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.

Wow, it's awesome to see you back! Your avatar is great and hopefully it doesn't disappear.

 

[Enderman]

Ok, lets talk about calculating Candela/lux. It much easier than you think.
I will show you a formula for calculating maximum center-beam Lux for any light with a lightsource and a reflector or optic. All you need is the diameter of the reflector/optic and the luminance of the light source.
Lets use your 100mm lens and a Cree XP-G2 as an example. Luminance values for the XP-G2 can be found in different threads in the German TLF Forum (sorry, no English, just use google translate). Here you can find a luminance values of many different LEDS (measured) and many other lightsources. TLF-member sma is an expert on this subject and has gone to painstaking effort to measure theses values as accurately as possible for him. You can see there that a Cree XP-G2 R5 mounted on copper "DTP" PCB will reach a maximum of 200cd/mm^2 under ideal conditions. The problem with this LED is that Cree increased the size of the DIE twice last year (see here). The larger the DIE, the smaller the luminance (unless there are much more lumens emitted from the larger DIE). The old R5 and S2 LEDs had the small DIE. Then came the S3 and S4 Bins which probably were one size larger. Later on Cree made the DIE bigger again. This is the size of the current S4-binned XP-G2s (and the luminance is probably not as high as before). Here is a measurement of a larger S4-binned emitter, probably the medium sized DIE. It's still quite good. Now wee want to find out how the luminance changes with the Wavien colar. sma also studied and measured this here (he used an old-style XP-G2 S2 and all three collar sizes). Generally at the maximum possible current and perfect focussing (very difficult with the Wavien collar) you can expect up to 2.2x the luminance (which is amazing). He measured 470cd/mm^2 @ 6A. I will use this value for my calculation.
Imagine that you are looking at the optic your light from where the hotspot would be. From this perspective the reflector/optic looks like a flat circle. We now need to calculate the area of the circle that is lit up by the LED (the part that is yellow). For a 100mm diameter lens, this is (50mm)^2*pi = 7854mm^2. Now all you have to do is multiply this with the luminance of your LED and subtract some losses.

Luminous intensity = luminance * surface_area_of_optic * losses_lens_transmission * losses_because_of_heat
= 470cd/mm^2 * 7854mm^2 * 0.92 * 0.95
= 3226266cd = 3.23Mcd

So if there are no substantial problems with your light and you are using a "good" XP-G2 @ 6A with an optimally placed collar and the 100mm fasttech lens is lit up completely by the LED, you should be getting 3 Million Candela.

Details on the formula I used can be found here. The well known DrJones might also have an English explanation on his website, but I am not able to open it.

Cool, thanks for all the work
Definitely was underestimating my results then!
Of course the lens is far from professional grade quality, and my collar focusing is + or - a tenth of a mm, so the final results will require tests irl, but it's nice to have an idea of what to expect

I just did a short range test for fun the other day (even though I need to measure at several hundred feet to get an accurate result), but just with a quick ~5m test of divergence the calculator showed 50M candlepower xD I thought that was pretty funny.
Unfortunately that is definitely not the real number :C

 

[Enderman]

Hey guys, I have a few questions so I'll just ask them in this thread rather than making another one:

1) how bad is the UV radiation from the HBO103W/2?
Not considering a focused beam, but just light shining directly on you from the bulb, only for a couple minutes or even less.
Is it as bad as sunlight? Or worse?
Looking into the beam can probably blind you but just seeing the bulb for a few seconds will not cause any damage correct?

2) does anyone have the emission "profile" of the HBO100 or 103 bulb?
The only thing I could find is this for a generic mercury lamp, but the HBO bulbs have that small metal cover on one end, and I'm not sure if that will significantly reduce the angle.
http://zeiss-campus.magnet.fsu.edu/articles/lightsources/images/mercurylampsfigure2.jpg

3) I would assume the anode (thick terminal) should be on the close side of the reflector and cathode on the opening side? So that the metal shield is reflecting backwards instead of forwards.

 

[PolarLi]

1) The UV question has been asked a few times before, and I have not seen any conclusive answers yet. Probably because it's impossible to give one...
Light directly from the lamp, without any lens protecting it, is theoretically worse than sunlight, because it emit UV-B and UV-C. But energy level and exposure time is the two main factors that will determine if you actually get any damage from it. My best suggestion is to simply wear long sleeves, gloves and a welding mask. Then you could be around that lamp for hours with no ill effects. That is a very safe and easy solution to a complicated question. If you are only exposed to spill light that bounce off a wall or something like that, I wouldn't personally worry about it for only a minute or two.

2) I don't have that. But you can get somewhat close by simply take a high res picture like this: https://images-na.ssl-images-amazon.com/images/I/61t36-OUXOL._SL1500_.jpg Then just draw a straight line from a point in the middle between the anode and cathode, so it just clear the metal shield. And draw one line in the other direction so it clears the widest part of the anode. The two lines will make a emission profile very similar to illustration you linked to.
Since this lamp has two hotspots, you could also draw two lines from each electrode tip in both directions.

3) In this case, yes. So avoid reflectors with very short focal lengths, as the light must clear the metal shield, so it can hit the outer edge of the reflector.
This lamp can operate vertical, but is special, because it's supposed to have the cathode up and anode down. I had no idea about this til I saw the spec sheet at Osram today... Normally it's the other way around.

 

[Enderman]

Thanks Polar!
Those are perfect answers

I was researching lenses to protect the front and didn't know if I should prioritize clarity or UV resistance first.
Since I'm really careful about handling and where I point my lights I will not worry so much about UV protection.

I'm trying to go with the longest focal length reflector possible that still collects almost all the light, because I don't want to use a retro-reflector for this project, just a simple maxabeam-like setup. Got about half the components sourced so far, looking to complete this project before 2018.

Thank you for the help and have a great day!

 

[PolarLi]

As I mentioned in another post above here, normal soda lime glass will block anything below 320 nm. And borosilicate block anything below approx 290-300 nm. (UV-B is 280-320 nm and UV-C is 200-280 nm) It's when or if you test the lamp without any lens you need to be really careful, not only because of a lot more UV, but also because of the explosion risk.

 

[Enderman]

That's true, I will definitely use safety glasses or work behind a protection screen when testing the lamp.
I'm thinking of getting my lens from flashlightlens.com since they sell custom sizes, and I will need a 154mm piece.

 

[Enderman]

I measured the angle from opposite points (aka hotspots) to get the maximum angle of the light using photoshop and a protractor image
From one side there is 30 degrees blocked by the anode (leaving 60 degrees of light) and on the other side there is 45 degrees (+-5) of light blocked by the metal shroud.
Total light opening is about 105 degrees.

Looking at the reflector I was planning to use, it makes more sense to have the lamp with the shroud on the back and anode on the front because more light will go to the farther edges of the reflector (which is better at collimating since the distance to the lamp is farther)
Here is a diagram of the reflector I am planning to use, 10mm focal length (same as the one in the maxabeam) https://www.desmos.com/calculator/hmdppunkqq

58.5 degrees from the focal point to the edge of the reflector, which is very close to the 60 I calculated above. Having the metal shroud forward will only let 45 degrees of light out that way resulting in a lot of wasted reflector area.
If I wanted to go that route I would need to use a shallower (longer focal length) reflector, but the next step up in focal length is 19mm and there is nothing available in between 10-19 (from phoenix, optiforms is too expensive)
The 19mm focal length reflector is this one https://www.desmos.com/calculator/u6kpal5vzu and it only does 37 degrees to the edge, which IMO is too much light lost, needed to be minimum 40-45 degrees.

 

[PolarLi]

I realize I forgot to mention one thing, the arc width. You could draw lines from the outer edge of the arc. You will end up with a slightly wider emission profile, but of course, with less intense light.

You can install the lamp with anode forward, but I can't tell you how it will react when you tilt the light up. It won't instantly explode or anything, but you could get flicker and arc wander (so it lose focus) and overheating after a few minutes. But again, I can't say this for sure.

 

[Enderman]

I realize I forgot to mention one thing, the arc width. You could draw lines from the outer edge of the arc. You will end up with a slightly wider emission profile, but of course, with less intense light.

You can install the lamp with anode forward, but I can't tell you how it will react when you tilt the light up. It won't instantly explode or anything, but you could get flicker and arc wander (so it lose focus) and overheating after a few minutes. But again, I can't say this for sure.

I did consider the arc, so i took my measurements from opposing points to get an overestimate rather than an underestimate.
Basically, the maximum possible angle that light can leave.

I'll do some research on how the lamps behave in different orientations, I didn't know that was a thing.

 

[Enderman]

Here are my angle calculations.
The angle of light towards the anode matches the HBO100 luminance profile image I found, 35 degrees.
The cathode end is reduced more though due to the metal shroud, and the HBO103 will have ~42 degrees blocked on that side, leaving 48 degrees of light.

When you zoom in to the full image to see the luminance profile image at the bottom, I drew red lines on there to show the angles where light is or is not blocked.
The green lines are the 38 degrees that this reflector captures, showing about 10 degrees of light that will be lost.
https://www.desmos.com/calculator/u6kpal5vzu

Having the cathode / metal shroud upwards might be the best option because this light will be pointing upwards a lot of the time, and flickering and fast degradation isn't something I would like.

 

[PolarLi]

Great illustrations! You can still add a little more for the arc width. It won't change the angle over the anode much, because you are real close to the lamp stem already. But it will give you 2-3 degrees extra over the metal shield (but with less intensity)

But what about going for the 19mm FL, and slightly up in diameter? 170-180 mm should be about perfect. And Phoenix can cut down a bigger reflector for you. Or, you can just bite the bullet and accept some losses. You will capture the most intense light anyway. I've been in the exact same dilemma myself lately, and I had to go for a non optimal reflector, because I already had the host. And as you probably know, a custom FL electroformed will cost you a lot money. :/

 

[Enderman]

Yes I think I will go with the 19mm reflector in order to have the lamp in the correct orientation, and also because this is a mercury lamp rather than xenon.
The two separate hotspots will end up more collimated and "together" with a longer focal length, which isn't necessary with the maxabeam since it only has one hotspot in the xenon lamp.
The longer FL should compensate for this, although I would expect a bit more beam divergence than the maxabeam (even though candlepower will still be much higher)

You're right I could extend the reflector and it would capture more light, but I really wanted to limit this light to 6" size so that in the future I could swap out the aluminum housing with a carbon fiber tube.
But maybe I can just make a "head" that attaches to the 6" tube and increases the diameter to 8" for the reflector?
I will graph the 19mm reflector with larger diameters and consider this option.

PS I really like cylinder lights with no large head

 

[Ra]

What amazes me, is that when I started my Maxablaster project threads here, only a few members were aware of what things were nessesary for obtaining the best throw.
And now many of you so much grew into this matter! Leaving not much for me to teach you.. You are the teachers now.

During the new year fireworks, the battery upgrade of Maxablaster proved its reliabillity, it was a nice sight to have it fully up and running again.

I hope I'm still allowed to give you all the best wishes for 2017..

 

[Enderman]

Happy 2017 to you too!

It's great to have a role model to look up to when building projects like this, saves a ton of money from trial and error xD