BLF recoil über-thrower

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Enderman
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Oh, now it looks really bad in comparison… :/
I’m going to email optiforms tonight and see how much a 4-6” reflector will cost.
If it’s under $100 I’ll go for it.

Jerommel
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Lexel wrote:
the cigarette lighter is not good enough

I did compared it now to a smaller projector lens.


Ah, that’s a pity..
Thanks for sharing.
And i bet you don’t even smoke either? Smile

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

Jerommel
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Enderman wrote:
Oh, now it looks really bad in comparison… :/
I’m going to email optiforms tonight and see how much a 4-6” reflector will cost.
If it’s under $100 I’ll go for it.
You’re gonna make us jealous. Smile

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

djozz
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@Lexel, is that spot from the lens just smaller or also much brighter?

link to djozz tests 

“I used to think that top environmental problems were biodiversity loss, ecosystem collapse and climate change. I thought that thirty years of good science could address these problems. I was wrong. The top environmental problems are selfishness, greed and apathy, and to deal with these we need a cultural and spiritual transformation. And we scientists don’t know how to do that.”   (Gus Speth)

Lexel
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the lens was 20cm from the LED
so overall brightness far less
and spot brightness better

both pictures use same camera settings
f2.8 1/40s ISO1600

Enderman
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Jerommel wrote:
You’re gonna make us jealous. Smile

Hah I wish, otherwise it will be a waste of $100 xd
Always good to experiment though and pass on information to others who want to try similar stuff.
Jerommel
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Could this be the good news we’re waiting for ??

The Miller wrote:
A BLFer contacted me and he is in contact with a Chinese company able to make any size reflector without minimum order quantity
He wants to order a sample of what would be a GT reflector and pm me with results to post (I think he got a little scared of by the little over the top discussion the last pages so for bow he does prefer me communicate about it.)

In others words, if a BLFer can do it so a manufacturer

Meaning we could just set the size and shape of a reflector and have some results of it pretty fast and can adjust design based on what we come up with as reflector, this is great news and requires me to edit topic title and OP but I cannot do that till much later today so hopefully you guys pick up on this post Wink

http://budgetlightforum.com/comment/1045375#comment-1045375

Say 4 inch diameter and deep enough to collimate 120° of the emitted light?
That would be totally awesome.

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

djozz
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Jerommel wrote:
Could this be the good news we’re waiting for ??

The Miller wrote:
A BLFer contacted me and he is in contact with a Chinese company able to make any size reflector without minimum order quantity
He wants to order a sample of what would be a GT reflector and pm me with results to post (I think he got a little scared of by the little over the top discussion the last pages so for bow he does prefer me communicate about it.)

In others words, if a BLFer can do it so a manufacturer

Meaning we could just set the size and shape of a reflector and have some results of it pretty fast and can adjust design based on what we come up with as reflector, this is great news and requires me to edit topic title and OP but I cannot do that till much later today so hopefully you guys pick up on this post Wink

http://budgetlightforum.com/comment/1045375#comment-1045375

Say 4 inch diameter and deep enough to collimate 120° of the emitted light?
That would be totally awesome.


Before random ordering a reflector size/focal length, we first must establish what ‘catch angle’ is optimal for a recoil reflector, and my suspicion is that 120 degrees is too much. My fear: the outer part of the reflector will produce a larger and fuzzier image of the die and therefore hardly contribute to the throw. As well as Lexel I will experiment with the cigarette lighter reflector to see if I find the same as with the Mirascope reflector.

link to djozz tests 

“I used to think that top environmental problems were biodiversity loss, ecosystem collapse and climate change. I thought that thirty years of good science could address these problems. I was wrong. The top environmental problems are selfishness, greed and apathy, and to deal with these we need a cultural and spiritual transformation. And we scientists don’t know how to do that.”   (Gus Speth)

EasyB
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I’m not trying to dissuade anyone from building a recoil reflector light, but it seems some are overestimating the improvement in light collection efficiency of a recoil setup over a traditional reflector setup. A typical traditional reflector (like a C8 reflector) already collects 75% of the light emitted (lumens) from the LED, so collecting 100% of the light would only be a 33% improvement.

Jerommel wrote:
Here are some cold hard reflector facts illustrated:

Based on what i go by in my images, maybe it should be a little deeper still, because as you can see the actual amount of light that is focussed by the reflector is quite small.
But that’s the case with all regular reflector lights..
The best bit is just spilled…

If you are trying to think about the total light collected by a reflector, the intensity vs angle plot (let’s call this angle theta) quoted above (from the giga thrower thread) doesn’t tell the whole story. This plot is a slice of the 3-dimensional beam profile. To get the total emitted light you have to consider this 3d shape. For example, the light is less intense at theta angles around 45 degrees, but there is actually a lot of total light in this region of theta angle because of the shape of the 3d beam; basically for the same reason a circle’s circumference gets larger as the diameter is increased. Mathematically, this means integrating around the other axis (the axis perpendicular to the LED surface). When you do this it adds a sin(theta) factor, so the total light emitted at different angles is now proportional to sin(theta)cos(theta). This is the multiplication of the intensity pattern (cos(theta)), which is greatest around 0 degrees, and sin(theta), which is greatest around 90 degrees. The result is a curve that peaks around 45 degrees.

We can get some number estimates by using wolfram alpha to integrate for us.
wolframalpha.com/input/?i=integrate+sin(x)cos(x)+from+0+to+1.57

This integrates all of the light from 0 to 90 degrees (1.57 radians) and the answer is 0.5. This is just a proportionality factor that we’ll use to compare future calculations.

Now, a C8 reflector is ~38mm wide and ~33mm deep. It collects light greater than half angle ~30degrees (inverse tan(38/(2*33))), which is about 0.523rad.

wolframalpha.com/input/?i=integrate+sin(x)cos(x)+from+.523+to+1.57
gives us ~0.375, or 75% of the total light.

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“Random ordering” ?

Anyway, we should have a look at how much light is emitted to the various angles.
Do consider though that a ‘normal’ reflector thrower uses all of the wide angled light too, so apparently it’s worthwhile.

Funny the previous post used this image too:

As you can see, contrary to what previous post claims, it’s more like 75% spill with a regular set up.
In the picture you can vaguely see the yellow lines that show that a recoil set up turns everything into a beam.
I have stopped at about 145° for both reflectors because the LED does not produce much light any further.
Moreover, it’s usually greenish brown light that comes from the sides, as you all may recognise in the coronas of regular flashlights.
And maybe that’s why flashlights often have a centring gasket with a collar that shrouds the wide angled light.

Either way, a regular reflector spills some 65° of the most intense light.
According to the picture we could limit the recoil reflector to where it is 50% intensity (relative to 100% @ 0°), which happens to be around 60°, thus 120° in total.
Maybe 110° is best, reducing the diameter some more.

(edit) I was wrong, EasyB was right…

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

EasyB
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Jerommel wrote:
As you can see, contrary to what previous post claims, it’s more like 66% spill with a regular set up.

I was attempting to explain in my post why your reasoning is incorrect. For example, an aspheric lens light usually collects a ~30degree half angle when focused. With your reasoning, wouldn’t you expect the light collection to be good in aspheric lights? Well, it is not good because it only collects ~25% of the total light. Djozz’s measurements here support that; just 21% of the total light from the LED is in the beam when in focus mode.

Jerommel
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EasyB wrote:
Jerommel wrote:
As you can see, contrary to what previous post claims, it’s more like 66% spill with a regular set up.

I was attempting to explain in my post why your reasoning is incorrect.

But it is not incorrect.
Just look at the radiation diagram of an LED and than superimpose that on the picture in the OP, and compare that to the picture above.
The recoil set up will focus all of it, including the 65° a regular reflector simply spills,which happens to be about 66% of the emitted lumens (my guesstimate).

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

EasyB
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Jerommel wrote:
EasyB wrote:
Jerommel wrote:
As you can see, contrary to what previous post claims, it’s more like 66% spill with a regular set up.

I was attempting to explain in my post why your reasoning is incorrect.

But it is not incorrect.
Just look at the radiation diagram of an LED and than superimpose that on the picture in the OP, and compare that to the picture above.

As I explained, that diagram doesn’t tell the whole story.

Let’s talk about the aspheric lens light. Why is the light collection so poor if it’s collecting the most intense light?

Enderman
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EasyB is 100% correct, I’m planning to add those functions to my reflector calculator soon.

Also with a parabolic reflector the outside of the mirror should not be creating a fuzzier image.
The ideal catch angle is 180 degrees for 100% light efficiency.
You can imagine it would collect the same 90 degrees as a smaller shallower reflector but if you keep extending the sides you will end up with a larger diameter reflector but 180 degree capture.

The problem is that the focal length gets shorter the more degrees of capture you try to cram into something tiny like 4 inches, and that is what will increase dispersion and “fuzzyness”
But if the focal length is too long, you will get a really light beam and low light efficiency.

Yesterday I was looking for other mirrors, I tested with one I had at home which didn’t focus very well (weird shaped spot) but it still collimated the light as good as a lens.
This will only get about 60-90 degrees from in front of the light, but I think it would work well
https://www.amazon.com/Harry-Koenig-Co-Magnification-Suction/dp/B0044FEH...
https://www.amazon.com/Zadro-EXtreme-Magnification-Mirror-Finish/dp/B001...
https://www.amazon.com/Floxite-Fl-15v-Strong-Supervision-Brushed/dp/B003...

Jerommel
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EasyB wrote:
Jerommel wrote:
EasyB wrote:
Jerommel wrote:
As you can see, contrary to what previous post claims, it’s more like 66% spill with a regular set up.

I was attempting to explain in my post why your reasoning is incorrect.

But it is not incorrect.
Just look at the radiation diagram of an LED and than superimpose that on the picture in the OP, and compare that to the picture above.

As I explained, that diagram doesn’t tell the whole story.

Let’s talk about the aspheric lens light.

We’re not discussing an aspheric lens here.
I think you don’t understand the radiation diagram.

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

Jerommel
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Enderman wrote:
EasyB is 100% correct,
His conclusion is not correct.
What’s so hard to get from that radiation diagram?
Just look at the surface area of the circle.
Only about 33% is green i.e. reflected with a regular reflector, whereas a recoil set up practically uses all of it, and when limited to 120° it still is almost 90%.
That’s nearly 3 times more light focussed / collimated for the recoil compared to the regular set up.

Why do you think i’m so enthusiastic about a recoil thrower?
LEDs are practically made for it.

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

EasyB
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Jerommel wrote:
Enderman wrote:
EasyB is 100% correct,
His conclusion is not correct.
What’s so hard to get from that radiation diagram?
Just look at the surface area of the circle.
Only about 33% is green i.e. reflected with a regular reflector, whereas a recoil set up practically uses all of it, and when limited to 120° it still is almost 90%.
That’s nearly 3 times more light focussed / collimated for the recoil compared to the regular set up.

Why do you think i’m so enthusiastic about a recoil thrower?
LEDs are practically made for it.

It’s clear you have not considered what I wrote in my post above (regarding how the radiation diagram does not tell the whole story) and so this discussion is just us repeating ourselves.

Jerommel
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And here’s the evidence again:

It seems to be about 2.5 times brighter (my guesstimate) than a regular reflector, and this is with a bad parabola for the recoil.

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

Theodore41
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EasyB wrote:
Jerommel wrote:
As you can see, contrary to what previous post claims, it’s more like 66% spill with a regular set up.

I was attempting to explain in my post why your reasoning is incorrect. For example, an aspheric lens light usually collects a ~30degree half angle when focused. With your reasoning, wouldn’t you expect the light collection to be good in aspheric lights? Well, it is not good because it only collects ~25% of the total light. Djozz’s measurements here support that; just 21% of the total light from the LED is in the beam when in focus mode.


…for this,some guys used wavien collars,so as to collect much more light,but it is not possible now,because those collars are not available now.
Jerommel
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EasyB wrote:
Jerommel wrote:
Enderman wrote:
EasyB is 100% correct,
His conclusion is not correct.
What’s so hard to get from that radiation diagram?
Just look at the surface area of the circle.
Only about 33% is green i.e. reflected with a regular reflector, whereas a recoil set up practically uses all of it, and when limited to 120° it still is almost 90%.
That’s nearly 3 times more light focussed / collimated for the recoil compared to the regular set up.

Why do you think i’m so enthusiastic about a recoil thrower?
LEDs are practically made for it.

It’s clear you have not considered what I wrote in my post above (regarding how the radiation diagram does not tell the whole story) and so this discussion is just us repeating ourselves.

You use terms i’m unfamiliar with, so it’s kind of wasted on me.
However, there’s not much more to the radiation diagram than what it shows us.
(edit) ehrmm… there is… sorry..(/edit)

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

Jerommel
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Theodore41 wrote:
EasyB wrote:
Jerommel wrote:
As you can see, contrary to what previous post claims, it’s more like 66% spill with a regular set up.

I was attempting to explain in my post why your reasoning is incorrect. For example, an aspheric lens light usually collects a ~30degree half angle when focused. With your reasoning, wouldn’t you expect the light collection to be good in aspheric lights? Well, it is not good because it only collects ~25% of the total light. Djozz’s measurements here support that; just 21% of the total light from the LED is in the beam when in focus mode.


…for this,some guys used wavien collars,so as to collect much more light,but it is not possible now,because those collars are not available now.
Better to use a primary lens, but that complicates things and you can not zoom out to such a wide flood anymore.

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

Enderman
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Jerommel wrote:
His conclusion is not correct.
What’s so hard to get from that radiation diagram?
Just look at the surface area of the circle.
Only about 33% is green i.e. reflected with a regular reflector, whereas a recoil set up practically uses all of it, and when limited to 120° it still is almost 90%.
That’s nearly 3 times more light focussed / collimated for the recoil compared to the regular set up.

Why do you think i’m so enthusiastic about a recoil thrower?
LEDs are practically made for it.


The radiation diagram is not of a circle, it is of a sphere.
The way the intensity is measure is with a fixed distance, so at 0 degrees it is Xcm in front of the led, at 45 degrees it is at Xcm diagonally from the LED, at 90 degrees it is at Xcm to the side of the LED.
I think you can imagine the circumference of the circle at different heights along a sphere, like this

But since the radius increases to the power of 1/2 and the intensity decreases by cosine then between -45 and 45 degrees there is over 50% light output.
So you’re both right, the intensity graph doesn’t tell the whole story and a recoil reflector is still definitely more efficient than forward reflectors or lenses.
Enderman
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Jerommel wrote:
His conclusion is not correct.
What’s so hard to get from that radiation diagram?
Just look at the surface area of the circle.
Only about 33% is green i.e. reflected with a regular reflector, whereas a recoil set up practically uses all of it, and when limited to 120° it still is almost 90%.
That’s nearly 3 times more light focussed / collimated for the recoil compared to the regular set up.

Why do you think i’m so enthusiastic about a recoil thrower?
LEDs are practically made for it.


The radiation diagram is not of a circle, it is of a sphere.
The way the intensity is measure is with a fixed distance, so at 0 degrees it is Xcm in front of the led, at 45 degrees it is at Xcm diagonally from the LED, at 90 degrees it is at Xcm to the side of the LED.
I think you can imagine the circumference of the circle at different heights along a sphere, like this

But since the radius increases to the power of 1/2 and the intensity decreases by cosine then between -45 and 45 degrees there is over 50% light output.
So you’re both right, the intensity graph doesn’t tell the whole story and a recoil reflector is still definitely more efficient than forward reflectors or lenses.
Enderman
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Jerommel wrote:
And here’s the evidence again:

It seems to be about 2.5 times brighter (my guesstimate) than a regular reflector, and this is with a bad parabola for the recoil.


Is this the wrong image? Silly
Jerommel
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Enderman wrote:
Jerommel wrote:
His conclusion is not correct.
What’s so hard to get from that radiation diagram?
Just look at the surface area of the circle.
Only about 33% is green i.e. reflected with a regular reflector, whereas a recoil set up practically uses all of it, and when limited to 120° it still is almost 90%.
That’s nearly 3 times more light focussed / collimated for the recoil compared to the regular set up.

Why do you think i’m so enthusiastic about a recoil thrower?
LEDs are practically made for it.


The radiation diagram is not of a circle, it is of a sphere.
The way the intensity is measure is with a fixed distance, so at 0 degrees it is Xcm in front of the led, at 45 degrees it is at Xcm diagonally from the LED, at 90 degrees it is at Xcm to the side of the LED.
I think you can imagine the circumference of the circle at different heights along a sphere, like this

But since the radius increases to the power of 1/2 and the intensity decreases by cosine then between -45 and 45 degrees there is over 50% light output.
So you’re both right, the intensity graph doesn’t tell the whole story and a recoil reflector is still definitely more efficient than forward reflectors or lenses.
Okay, thanks for explaining that, especially the picture showing it is (of course! silly me..) a sphere.
This also makes sense as to why i felt that we should collimate at least 120°
And afterall, had i been right, a regular reflector would be quite silly for an LED, and there would be a LOT of silly lights out there.

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

Jerommel
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Enderman wrote:
Jerommel wrote:
And here’s the evidence again:
It seems to be about 2.5 times brighter (my guesstimate) than a regular reflector, and this is with a bad parabola for the recoil.

Is this the wrong image? Silly
How so?

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

Jerommel
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EasyB wrote:
Jerommel wrote:
Enderman wrote:
EasyB is 100% correct,
His conclusion is not correct.
What’s so hard to get from that radiation diagram?
Just look at the surface area of the circle.
Only about 33% is green i.e. reflected with a regular reflector, whereas a recoil set up practically uses all of it, and when limited to 120° it still is almost 90%.
That’s nearly 3 times more light focussed / collimated for the recoil compared to the regular set up.

Why do you think i’m so enthusiastic about a recoil thrower?
LEDs are practically made for it.

It’s clear you have not considered what I wrote in my post above (regarding how the radiation diagram does not tell the whole story) and so this discussion is just us repeating ourselves.


I get it now, i needed a picture…
Thanks for trying though. Thumbs Up

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

Jerommel
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But then i still don’t understand why an aspheric lens out throws a forward reflector light.. Question

..waiting for parts..

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Enderman
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Jerommel wrote:
Okay, thanks for explaining that, especially the picture showing it is (of course! silly me..) a sphere.
This also makes sense as to why i felt that we should collimate at least 120°
And afterall, had i been right, a regular reflector would be quite silly for an LED, and there would be a LOT of silly lights out there.

You’re welcome Smile

Jerommel wrote:
Enderman wrote:

Is this the wrong image? Silly
How so?

A picture of plants? Am I missing something? What “evidence” is that for? lol
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Plants??

It’s the beamshots from page 6:

http://budgetlightforum.com/comment/1036494#comment-1036494

(isn’t it?)

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

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