Longer throw without changing the driver !! :) Prototype is done and now it's time for testing.. ( more beam shots)

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dct73
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NZ Shooter wrote:
dct73 wrote:
NZ Shooter wrote:
Rufusbduck wrote:
When you stuck your finger in the hose it went farther but less water actually came out.

Sorry fella, totally incorrect.

Fill up a bucket with an un-restricted hose, time how long it takes.

Do it again, same bucket, same hose flow with your finger partly over the end.

The times will be the same ( give or take a second or two, as you may not stop at exactly the same fill line )

Less water runs out, but at a faster rate. Equaling identical water flow, say litres / minute.

I’m going to pile on mister know it all here. Sorry fella, YOU are totally incorrect. Do your experiment accurately and you will find out the times are NOT the same. By putting your finger over the hose you introduced a restriction to the flow so the actual flow goes down. The only way you can maintain the same flow in the restricted line is to increase the pressure.

I wasn’t going to re-post in this thread, as there was no need – until now :bigsmile:

This quote was taken from an astro-physicists work (copied & pasted )
Please note the part I underlined, it was already in brackets.

Question

Why is it that when you put your finger over the tip of a hose the water shoots out farther?

Asked by: Sparrow

Answer

The answer centers on the idea of matter conservation. If a certain amount of water flows into the hose from the spigot, that water must either flow out of the hose at the other end, or accumulate inside the hose itself. Since a garden hose is made of stiff plastic (generally), it won’t expand to let more water accumulate, so the water must eventually flow out of the end of the hose. When you put your finger over the tip of the hose, you decrease the amount of space the water has to flow through. Since the same amount of water has to flow out of the hose before and after you place you finger over the end, the water must shoot out faster (to keep the amount of water flowing out a constant). And, thus, since the water shoots out faster, it travels farther. To find further information about this, I would suggest any basic physics textbook, or, more in-depth, a textbook on fluid mechanics.

Answered by: Andreas Birkedal-Hansen, M.A., Physics Grad Student, UC Berkeley

Here is the link, so you know I didn’t just type it up myself Smile

http://www.physlink.com/education/askexperts/ae185.cfm

That is correct. Note your astro-physicist said “if a certain amount of water flows into the hose from the spigot”. By placing your finger over the end of the hose you introduced a restriction to the flow. Unless you increase the pressure the water no longer enters the hose at the same rate. ie. that certain amount of flow into the hose has changed. The flow has decreased and will take longer to fill your bucket. Just like he says, I suggest you look in any physics book. This reminds me of a favorite quote. A little knowledge is a dangerous thing.

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dct73 wrote:
Note your astro-physicist said “if a certain amount of water flows into the hose from the spigot”. By placing your finger over the end of the hose you introduced a restriction to the flow. Unless you increase the pressure the water no longer enters the hose at the same rate. ie. that certain amount of flow into the hose has changed. The flow has decreased and will take longer to fill your bucket. Just like he says, I suggest you look in any physics book. This reminds me of a favorite quote. A little knowledge is a dangerous thing.

If my water hose is smaller than my main and my pressure regulator is set lower than the community pressure, then wouldn’t the flow rate remain the same until the back-pressure exceeds the inlet? The higher community pressure would fill the home system and effectively provide the higher pressure to the hose inlet, assuming it is not exceeding the main/regulatory capacity (and restrictive back-pressure), correct?

Since the quote had a stated and potentially valid assumption, perhaps people could contemplate how to improve the experiment and/or confirm its bounds?

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Happy New Year everyone!

Let’s put this bad part of this thread behind us. It’s a new year. So let’s try to be nice to others. If we do that throughout the whole year, think of how much better this place will be.

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Daylighter ,
Thank you very much for all your effort!!!
I really appreciate your great attitude! While people saying bad things and trying to correct you on your ‘wrong’ scientifically naming, you stayed with your head cool,
You showed that your 502b with the lens had a higher lux reading at a certain point, and by some comments people showed that your original idea works..
No, not with all lights etc, but it’s just fun to do, and I enjoyed seeing it!

Pity that people start calling it names, because its not cool enough or not great enough to increase lux/ throw with the more expensive ‘throwers’!

You proved with the pictures what your point was with the 502b, with and without that lens!
Game over Wink

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skyrider1 wrote:
The 300ft beamshot was with a telescope, not his mod.

The problem in this thread is all the terms being thrown around without proper understanding of what they mean. (I myself probably made some errors). Another problem is the contradictions of the OP bringing in the telescope and his mod. They are very different, 2 lens vs 1 lens.

you’re right.. i’m sorry if i did it with my telescope instead my mod.. i guess you didn’t read the comment that i made regarding this mod.
it is based on the telescope, i’m trying to build a bigger one so i can use it to test my other lights.
so.. here’s the picture of the same light trustfire wf 502b that was used with the telescope, this time i’m using it in my mod.. enjoy Smile
same shot.. building is about 300’ away ( maybe more.. i’ll double check with google earth later)
control shot.. daytime
Photobucket

same trustfire WF502B inside the mod ( i use low mode for picture so it won’t wash out)
Photobucket

Trustfire WF 502B throw( notice the doughnut ring.. at this distance the light started losing it’s hotspot) but it still can reach!
Photobucket

The only way to do a great work is to love what you do.

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NZ Shooter wrote:
dct73 wrote:
NZ Shooter wrote:
Rufusbduck wrote:
When you stuck your finger in the hose it went farther but less water actually came out.
Sorry fella, totally incorrect. Fill up a bucket with an un-restricted hose, time how long it takes. Do it again, same bucket, same hose flow with your finger partly over the end. The times will be the same ( give or take a second or two, as you may not stop at exactly the same fill line ) Less water runs out, but at a faster rate. Equaling identical water flow, say litres / minute.
I'm going to pile on mister know it all here. Sorry fella, YOU are totally incorrect. Do your experiment accurately and you will find out the times are NOT the same. By putting your finger over the hose you introduced a restriction to the flow so the actual flow goes down. The only way you can maintain the same flow in the restricted line is to increase the pressure.
I wasn't going to re-post in this thread, as there was no need - until now :bigsmile: This quote was taken from an astro-physicists work (copied & pasted ) Please note the part I underlined, it was already in brackets. Question Why is it that when you put your finger over the tip of a hose the water shoots out farther? Asked by: Sparrow Answer The answer centers on the idea of matter conservation. If a certain amount of water flows into the hose from the spigot, that water must either flow out of the hose at the other end, or accumulate inside the hose itself. Since a garden hose is made of stiff plastic (generally), it won't expand to let more water accumulate, so the water must eventually flow out of the end of the hose. When you put your finger over the tip of the hose, you decrease the amount of space the water has to flow through. Since the same amount of water has to flow out of the hose before and after you place you finger over the end, the water must shoot out faster (+to keep the amount of water flowing out a constant+). And, thus, since the water shoots out faster, it travels farther. To find further information about this, I would suggest any basic physics textbook, or, more in-depth, a textbook on fluid mechanics. Answered by: Andreas Birkedal-Hansen, M.A., Physics Grad Student, UC Berkeley Here is the link, so you know I didn't just type it up myself Smile http://www.physlink.com/education/askexperts/ae185.cfm[/quote]

That's the problem with a "student" having an extremely narrow field of knowledge.  He was right, conversation of energy is at play.  The restriction on the hose can allow the pressure to increase the rate of flow at other open spigots, or it can cause energy to change into heat buildup in the pumps trying to move the water, or a gravity system can result in a higher water level at the source...among the many possibilities.  If this "student" was actually right, faucets would be atrocious devices to use as they'd always either be completely on or completely off, and if all spigots were completely off, the system would burst to allow the constant flow of water to remain unchanged.  As those of us in tune with the real world know, this is not the case.

The low mode should be lower.

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That’s pretty cool that it reached that far with your mod.

It looks like you have spent more time building and put 2 lens into your mod or did you just extend it a lot?

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ChibiM wrote:
Daylighter ,
Thank you very much for all your effort!!!
I really appreciate your great attitude! While people saying bad things and trying to correct you on your ‘wrong’ scientifically naming, you stayed with your head cool,
You showed that your 502b with the lens had a higher lux reading at a certain point, and by some comments people showed that your original idea works..
No, not with all lights etc, but it’s just fun to do, and I enjoyed seeing it!

Pity that people start calling it names, because its not cool enough or not great enough to increase lux/ throw with the more expensive ‘throwers’!

You proved with the pictures what your point was with the 502b, with and without that lens!
Game over Wink


Cheers Beer and Happy New Year!! Party

The only way to do a great work is to love what you do.

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skyrider1 wrote:
That’s pretty cool that it reached that far with your mod.

It looks like you have spent more time building and put 2 lens into your mod or did you just extend it a lot?


no.. it was still using 1 lens in front of the tube, a magnifying glass 2X power ( i wonder what 5X can do.. does it makes any different?.. i guess i gotta buy one to find out LOL
as for the tube.. for longer throw, you do need to increase the length of the tube ( just like telescope.. sometimes you need to adjust the length to get clearer picture)
if you just want to shoot something like 50’ away.. an 8” tube should do just fine ( the hotspot is brighter than the original without the doughnut hole)

The only way to do a great work is to love what you do.

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ma_sha1 wrote:
I resisted posting for two days, lol, I am going to give it one more try with the intent to clarify things for forum readers, especially those new to optical lens for flashlight use :). It's very confusing, so bear with me. The OP's thread actually started here: " http://budgetlightforum.com/node/16544#node-16544": http://budgetlightforum.com/node/16544#node-16544 It was using a lens that looks like a long EFL fresnel lens directly on top of the flashlight, don't know why all the photos were gone, but anyways, my comments started there & followed here when OP started a new thread with what looked like the same device. All my comments, when I said it won't wk, stated it's for long EFL lens, where the focal length is much longer than the distance between led & the lens. Scaru's test that confirmed my statements probably used long EFL fresnel lens, more inline with OP's initial experiments. This optical principle only partially apply to Medium EFL lens depends on where is the placement of led in relation to the lens focal point. and depends on the size of original reflector., thus the throw of original flashlight, in relation to the size of added lens. What's further complicating this thread is that it looks like mixing of original long EFL lens now with devices with medium EFL lens as well as telescopes, without separating the various lens as well as lens vs telescope & using them to support each other. I think we pretty much figured out which shots are from telescope, I am going to focus on the remaining confusion, what's happening when Medium EFL lens are used? When OP place a 3" medium EFL lens, mounted in a tube 8" away from the flashlight, if the lens has an EFL of 8" or so, this basically create an Aspherical flashlight, just not as efficient as typical aspherical flashlight, which use short EFL lens, so that it can be placed very close to led to collect a bigger angle of light spread. The lens placed far away like 8", only collect a small angle of beam coming from the led. None the less, if the led is placed at the focal point of a medium EFL lens, it'll have the same effect as typical aspherical flashlight and increase throw. As we all know, the throw of Aspheric flashlight is based on the diameter of the lens, thus OP was able to make it throw much further by using a 3" lens over a small reflector flashlight. May be OP can measure the EFL & confirm that he is actually placing the led at the focal point for his later single lens device, i.e actually making an aspheric flashlight? If this is the case, it's possible to explain why it works better in a floody light but not so much in a thrower. A floody light typically have very small reflector, most of the light comes out as spill, the lens collect the spill & turns it into parallel beam, in the mean time, diverge the original parallel beam from reflector so that the throw from reflector is lost. because the large lens works much more efficiently than a small reflector, the net effect is much increased throw. The gain is much greater than the loss. On the other hand, a thrower flashlight usually has a large reflector, TN31 3", SR90, SR95 UT 3.5", they are able to collect majority of the light & send them out as parallel beam to have great throw to begin with. With the lens of similar diameter,3" for example, if the led is placed at the focal point, the lens will still collect the spill & turn it into throw, but in the mean time, diverge & mess-up the original throw from the reflector, because the original throw may be greater, the lens may not provide improvement, especially a low quality lens placed 8" away. In a nuts shell, There are total of at least three type of optical systems experimented by the OP, improve throw or not will depend on the EFL of the lens, the placement of led, and the original reflector size in relation to the diameter of added lens. 1. Long EFL lens placed in front of a flashlight: Will not increase throw, it's not practical to place led at the focal point as its to long. 2. Medium EFL lens, with flashlight led placed at or near EFL: Will increase throw, rather than a shocking new discovery, it's just a less practical & less efficient form of aspheric flashlight setup, non the less, follow the same principle. 3. Telescope placed in front of a flashlight: Will increase throw. Not practical but I do find it interesting, especially if it has a really big front lens. I do want to apologize for using the elephant story to make my point, even if its out of frustration triggered by wild claims & great confusion, it was inappropriate for me to do so.

Thanks for that comprehensive explanation. Best post of the thread IMO.

Happy new year everyone!

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Someone needs to alert Mythbusters of the finger over the hose problem!

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Steve_the_Chief wrote:

ma_sha1 wrote:
I resisted posting for two days, lol, I am going to give it one more try with the intent to clarify things for forum readers, especially those new to optical lens for flashlight use :). It’s very confusing, so bear with me. The OP’s thread actually started here: “ http://budgetlightforum.com/node/16544#node-16544”: http://budgetlightforum.com/node/16544#node-16544 It was using a lens that looks like a long EFL fresnel lens directly on top of the flashlight, don’t know why all the photos were gone, but anyways, my comments started there & followed here when OP started a new thread with what looked like the same device. All my comments, when I said it won’t wk, stated it’s for long EFL lens, where the focal length is much longer than the distance between led & the lens. Scaru’s test that confirmed my statements probably used long EFL fresnel lens, more inline with OP’s initial experiments. This optical principle only partially apply to Medium EFL lens depends on where is the placement of led in relation to the lens focal point. and depends on the size of original reflector., thus the throw of original flashlight, in relation to the size of added lens. What’s further complicating this thread is that it looks like mixing of original long EFL lens now with devices with medium EFL lens as well as telescopes, without separating the various lens as well as lens vs telescope & using them to support each other. I think we pretty much figured out which shots are from telescope, I am going to focus on the remaining confusion, what’s happening when Medium EFL lens are used? When OP place a 3” medium EFL lens, mounted in a tube 8” away from the flashlight, if the lens has an EFL of 8” or so, this basically create an Aspherical flashlight, just not as efficient as typical aspherical flashlight, which use short EFL lens, so that it can be placed very close to led to collect a bigger angle of light spread. The lens placed far away like 8”, only collect a small angle of beam coming from the led. None the less, if the led is placed at the focal point of a medium EFL lens, it’ll have the same effect as typical aspherical flashlight and increase throw. As we all know, the throw of Aspheric flashlight is based on the diameter of the lens, thus OP was able to make it throw much further by using a 3” lens over a small reflector flashlight. May be OP can measure the EFL & confirm that he is actually placing the led at the focal point for his later single lens device, i.e actually making an aspheric flashlight? If this is the case, it’s possible to explain why it works better in a floody light but not so much in a thrower. A floody light typically have very small reflector, most of the light comes out as spill, the lens collect the spill & turns it into parallel beam, in the mean time, diverge the original parallel beam from reflector so that the throw from reflector is lost. because the large lens works much more efficiently than a small reflector, the net effect is much increased throw. The gain is much greater than the loss. On the other hand, a thrower flashlight usually has a large reflector, TN31 3”, SR90, SR95 UT 3.5”, they are able to collect majority of the light & send them out as parallel beam to have great throw to begin with. With the lens of similar diameter,3” for example, if the led is placed at the focal point, the lens will still collect the spill & turn it into throw, but in the mean time, diverge & mess-up the original throw from the reflector, because the original throw may be greater, the lens may not provide improvement, especially a low quality lens placed 8” away. In a nuts shell, There are total of at least three type of optical systems experimented by the OP, improve throw or not will depend on the EFL of the lens, the placement of led, and the original reflector size in relation to the diameter of added lens. 1. Long EFL lens placed in front of a flashlight: Will not increase throw, it’s not practical to place led at the focal point as its to long. 2. Medium EFL lens, with flashlight led placed at or near EFL: Will increase throw, rather than a shocking new discovery, it’s just a less practical & less efficient form of aspheric flashlight setup, non the less, follow the same principle. 3. Telescope placed in front of a flashlight: Will increase throw. Not practical but I do find it interesting, especially if it has a really big front lens. I do want to apologize for using the elephant story to make my point, even if its out of frustration triggered by wild claims & great confusion, it was inappropriate for me to do so.

Thanks for that comprehensive explanation. Best post of the thread IMO.

Happy new year everyone!

you are welcome, happy new year!

ChibiM
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Long story short, the OP was right!

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Hi guys,

Could everyone who has posted in this thread please read through their words and make sure they aren’t offensive or vulgar? In that case, the Edit button is waiting for you. Wink Feel free to disagree with anybody’s statements about flashlights, but under no circumstances should that translate into personal insults.

Budget Light Forum ...where Frugal meets with Flashlight!

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GottaZoom wrote:
dct73 wrote:
Note your astro-physicist said “if a certain amount of water flows into the hose from the spigot”. By placing your finger over the end of the hose you introduced a restriction to the flow. Unless you increase the pressure the water no longer enters the hose at the same rate. ie. that certain amount of flow into the hose has changed. The flow has decreased and will take longer to fill your bucket. Just like he says, I suggest you look in any physics book. This reminds me of a favorite quote. A little knowledge is a dangerous thing.

If my water hose is smaller than my main and my pressure regulator is set lower than the community pressure, then wouldn’t the flow rate remain the same until the back-pressure exceeds the inlet? The higher community pressure would fill the home system and effectively provide the higher pressure to the hose inlet, assuming it is not exceeding the main/regulatory capacity (and restrictive back-pressure), correct?

Since the quote had a stated and potentially valid assumption, perhaps people could contemplate how to improve the experiment and/or confirm its bounds?

Your garden hose is not a constant flow system. That is the problem with NZ Shooter’s supporting evidence. He is comparing apples to oranges so to speak. A garden hose is mostly a constant pressure system. I say mostly because there may be line losses in the plumbing system once the flow rate goes high enough that could cause a pressure DROP at the hose entrance.

“The higher community pressure would fill the home system and effectively provide the higher pressure to the hose inlet…..”
If the higher community pressure provides the higher pressure at the hose inlet then the pressure regulator isn’t working. If the pressure regulator isn’t working the system will already be at the higher pressure.

Here is a simple experiment everyone here can relate to. Instead of using your finger over the hose, lets use the faucet over your pipes at the sink. Open the faucet all the way and time how long it takes to fill a pitcher. Next barely crack the faucet and time how long it takes to fill the pitcher. It will be obvious the flow rate has decreased. Do I need to continue?

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sb56637 wrote:
Hi guys, Could everyone who has posted in this thread please read through their words and make sure they aren't offensive or vulgar?

I was never here Wink

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DayLighter: what about a beamshot without your mod at the same spot?

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sb56637 wrote:
Hi guys,

Could everyone who has posted in this thread please read through their words and make sure they aren’t offensive or vulgar? In that case, the Edit button is waiting for you. Wink Feel free to disagree with anybody’s statements about flashlights, but under no circumstances should that translate into personal insults.


+1 agreed Smile

The only way to do a great work is to love what you do.

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i doubt it very much the light will hit that building, as it is a flooder light.
the only thing it can do is annoy my neighbors by shooting light at their windows Big Smile
but in the name of science.. why not? will try to get it done tonight when it gets dark

The only way to do a great work is to love what you do.

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Smile Smile Smile
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here’s your requested trustfire 502b beamshot without the mod.
Photobucket

The only way to do a great work is to love what you do.

ChibiM
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But it looks like you focused it on the house, not on the tower Wink
Maybe 1 more pic?

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ChibiM wrote:
But it looks like you focused it on the house, not on the tower Wink
Maybe 1 more pic?

it was focused on the tower..i think what you see is the spill from the light.. remember that this light is a flooder:)
like i predicted before.. this light will not be able to reach those tower in the back.

The only way to do a great work is to love what you do.

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dct73 wrote:
Your garden hose is not a constant flow system. That is the problem with NZ Shooter’s supporting evidence. He is comparing apples to oranges so to speak. A garden hose is mostly a constant pressure system. I say mostly because there may be line losses in the plumbing system once the flow rate goes high enough that could cause a pressure DROP at the hose entrance.

“The higher community pressure would fill the home system and effectively provide the higher pressure to the hose inlet…..”
If the higher community pressure provides the higher pressure at the hose inlet then the pressure regulator isn’t working. If the pressure regulator isn’t working the system will already be at the higher pressure.

Here is a simple experiment everyone here can relate to. Instead of using your finger over the hose, lets use the faucet over your pipes at the sink. Open the faucet all the way and time how long it takes to fill a pitcher. Next barely crack the faucet and time how long it takes to fill the pitcher. It will be obvious the flow rate has decreased. Do I need to continue?

A pressure regulator is a max pressure limit at the home’s entry point. When the home pressure drops below the max, the higher community pressure will raise the pressure back to the max – much more quickly when community pressure is relatively very high. It is a maximum pressure, not constant pressure system. Pressure will fall and rise inside the system based on outflows. It’s also a max flow system, and when the pressure is being held closely to max, it approaches constant flow (for a given flow rate).

Closing a faucet gate doesn’t accelerate the water; the analogy is imperfect. When the hose exit volume is larger than the faucet flow, the outlet pressure would be lower than the inlet. In such a case, the restriction is not reducing flow until the restriction goes below the faucet flow rate. Up to that point, the pressure increase is related to constant flow. Beyond that point the restriction reduces flow, as does a gate in the faucet.

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VERY cool, just what I was looking for. I’m trying to make a long throw searchlight bright enough to take a telephoto/video shot up to 900 yards (half a mile). So I bought 8 1800 lumen T6 flashlights (cheap) to make something cost effective and ‘off the shelf’. Needless to say I was disappointed in the less than 1/4 mile performance.

These Surefire lights are certainly bright but I don’t buy the 1800 lumen rating. Anyway these focusing lights use a thick fisheye lense which will occlude some light. A (thin) fresnel lense as suggested sounds like a much bettter idea. If it can thow better than a fisheye then I’m back in business. Smile

Doc Skinner

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@DayLighter: Thanks, but could you post your pics with size set to 100% please?

Your lens must be totally different from mine.. my P60 hotspot didnt get any brighter nor did it throw further, but the hotspot became really ugly. Like yours, with the emitter projectede in the middle.

@GottaZoom: Finger on hose -> less water. Its not that hard.

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NightCrawl wrote:

DayLighter: Thanks, but could you post your pics with size set to 100% please?</p><p>Your lens must be totally different from mine.. my P60 hotspot didnt get any brighter nor did it throw further, but the hotspot became really ugly. Like yours, with the emitter projectede in the middle.</p><p>GottaZoom: Finger on hose -> less water. Its not that hard.


um.. 100%? how you do that? i just posted through photobucket..
which light do you have?

The only way to do a great work is to love what you do.

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Last seen: 5 years 6 months ago
Joined: 11/29/2012 - 01:22
Posts: 2829
Location: New York City

Doc Skinner wrote:
VERY cool, just what I was looking for. I’m trying to make a long throw searchlight bright enough to take a telephoto/video shot up to 900 yards (half a mile). So I bought 8 1800 lumen T6 flashlights (cheap) to make something cost effective and ‘off the shelf’. Needless to say I was disappointed in the less than 1/4 mile performance.

These Surefire lights are certainly bright but I don’t buy the 1800 lumen rating. Anyway these focusing lights use a thick fisheye lense which will occlude some light. A (thin) fresnel lense as suggested sounds like a much bettter idea. If it can thow better than a fisheye then I’m back in business. Smile


sorry to dissapoint you my friend, the only way you can achive that far would be with HID thrower.. something with at least 6” reflector
however… there’s away to create one.. without using hid light, i believe it’s involved with using aspherical lens in front of LED and then a big 10” telescope lens in the front.. it’ll probably will be able to shoot a mile away
i’m trying to recreate that experiment in smaller scale.. i’ll be happy if i can shoot 500’ using a small and cheap flashlight such as trustfire wf 502b

BTW.. welcome to BLF Smile

The only way to do a great work is to love what you do.

NightCrawl
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Last seen: 6 years 8 months ago
Joined: 01/22/2012 - 08:20
Posts: 3071
Location: Karlsruhe, Germany

DayLighter wrote:
NightCrawl wrote:

@DayLighter: Thanks, but could you post your pics with size set to 100% please?

Your lens must be totally different from mine.. my P60 hotspot didnt get any brighter nor did it throw further, but the hotspot became really ugly. Like yours, with the emitter projectede in the middle.

@GottaZoom: Finger on hose -> less water. Its not that hard.

um.. 100%? how you do that? i just posted through photobucket.. which light do you have?

When you insert a picture, in simple post editor its "relative width" or in advanced you have to click "appearance", enter 100% in the first field and empty the second. This way the pictures will adapt to the viewer resolution.

I have an L2P with a P60 dropin driven at 3.5A.

DarkSide
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Last seen: 5 years 2 months ago
Joined: 06/04/2012 - 01:50
Posts: 792
Location: NYC

 


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