Big Spotlight found! Is it worth a shot?

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bibihang
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Big Spotlight found! Is it worth a shot?

I wonder if anyone has tried this GDLITE spotlight? The link is here.

I saw one selling in a local hardware store at about $30 only. This light seems to be modified from a halogen version and it has very big reflector with an XM-L2 in it!

These are the photos I took. It also does look like one of the Cyclops Thor halogen spotlights,

I am still thinking whether I should grab one just for the fun, but on the other hand I am worried about it having poor/no heatsink.

Edited by: bibihang on 01/01/2015 - 20:28
eas
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Looks like an interesting host for a mod. You could fit a lot of cells that thing. I wonder if the reflector is aluminum, if so, it could help with thermal management.

Fritz t. Cat
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The advantage of the size is that, if the reflector is a good parabola and is shiny enough, it will have a very small spot and therefore lots of throw. From the shape, it will also have a lot of spill. It looks like a long focal length, as used in incandescent flashlights, that is shallow, so the spot will be small and warm, but most of the light will go into spill.

Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔,以及在陶器。

L4M4
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This looks like a light made for a H4/H7 bulb.
Then they said “We need a LED light and we have plenty of those hosts…”

I don’t think that this light will be only near to good, will have a very weak spot and a ton of spill.
Also the LED won’t have any cooling (just my guess).

For 30$ you can get 2 good Convoys Wink

dchomak
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Here is an XM-L in a 9” reflector. I had to mount the LED out quite a ways in order for the hot spot to focus. As others said, the hot spot was weak (although very well defined) and there was a LOT of spill. Not at all useful for such a big and heavy light.

From the positioning of the LED in your photo, I would imagine that the hot spot would be so out of focus that there would be no hot spot, but rather just flood. That type of beam could also be done so easily with a small reflector and smaller light, so why do it this way?

Bort
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I wonder if the flat spot is bad for the focus, if it were all cone it would probably throw a lot better?

The Journal of Alternative Facts TM

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wight
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Bort wrote:
I wonder if the flat spot is bad for the focus, if it were all cone it would probably throw a lot better?
The flat spot really isn’t that relevant. The (probable) reason it’s there is just to fill space. The focal point for the reflector (on the front to back axis) is probably right where the LED is now. Since the LED does not shine light towards the back at all (unlike incan) there’s no point in continuing the cone back behind the LED. Take a look at dchomack’s picture of a user-converted light to get a better idea what I’m talking about.

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
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wight wrote:
Bort wrote:
I wonder if the flat spot is bad for the focus, if it were all cone it would probably throw a lot better?
The flat spot really isn’t that relevant. The (probable) reason it’s there is just to fill space. The focal point for the reflector (on the front to back axis) is probably right where the LED is now. Since the LED does not shine light towards the back at all (unlike incan) there’s no point in continuing the cone back behind the LED. Take a look at dchomack’s picture of a user-converted light to get a better idea what I’m talking about.

I don’t quite understand, bigger reflectors seem to increase throw, My Convoy S2 is very floody, my M1 more throwy, and C8 much throwier. So Would this reflector not throw even furthur being so much larger?
Also i assume angle of reflector affects throw in some manner.

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

bibihang
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Thanks for all the feedback guys. Smile

I forgot to mention that I did try and switched on this spotlight at the hardware store. At around 5 meters the hotspot is well defined and there is no black hole appeared in the middle. Does it mean the focusing is quite okay?

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bibihang wrote:
Thanks for all the feedback guys. Smile

I forgot to mention that I did try and switched on this spotlight at the hardware store. At around 5 meters the hotspot is well defined and there is no black hole appeared in the middle. Does it mean the focusing is quite okay?


You should try and light up the far end of the store (if its big box) and take a C8 with you for comparison

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

wight
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Bort wrote:
wight wrote:
Bort wrote:
I wonder if the flat spot is bad for the focus, if it were all cone it would probably throw a lot better?
The flat spot really isn’t that relevant. The (probable) reason it’s there is just to fill space. The focal point for the reflector (on the front to back axis) is probably right where the LED is now. Since the LED does not shine light towards the back at all (unlike incan) there’s no point in continuing the cone back behind the LED. Take a look at dchomack’s picture of a user-converted light to get a better idea what I’m talking about.

I don’t quite understand, bigger reflectors seem to increase throw, My Convoy S2 is very floody, my M1 more throwy, and C8 much throwier. So Would this reflector not throw even furthur being so much larger?
Also i assume angle of reflector affects throw in some manner.
I thought I hit the nail on the head.. I’m not really sure what to add without writing a novel? (and I’m certainly not qualified to write volumes on the subject).

Let’s step through it:

  1. We know how incan reflectors focus (not all the way at the back)
  2. The LED must be in focus
  3. Therefore we must place the LED in the middle, where the focal point is
  4. The space behind the LED is wasted and podiums are expensive to make and may look dumb to consumers.
  5. Therefore we lop off the leftover, wasted reflector from behind the LED and get to skip making a podium. We also get a chance to reduce overall depth when doing this. Win-Win for the lame manufacturer.

That all seems to add up to me, but if you still don’t see what I’m saying maybe we can try and figure out where communication or logic is breaking down.

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

Bort
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wight wrote:
Bort wrote:
wight wrote:
Bort wrote:
I wonder if the flat spot is bad for the focus, if it were all cone it would probably throw a lot better?
The flat spot really isn’t that relevant. The (probable) reason it’s there is just to fill space. The focal point for the reflector (on the front to back axis) is probably right where the LED is now. Since the LED does not shine light towards the back at all (unlike incan) there’s no point in continuing the cone back behind the LED. Take a look at dchomack’s picture of a user-converted light to get a better idea what I’m talking about.

I don’t quite understand, bigger reflectors seem to increase throw, My Convoy S2 is very floody, my M1 more throwy, and C8 much throwier. So Would this reflector not throw even furthur being so much larger?
Also i assume angle of reflector affects throw in some manner.
I thought I hit the nail on the head.. I’m not really sure what to add without writing a novel? (and I’m certainly not qualified to write volumes on the subject).

Let’s step through it:

  1. We know how incan reflectors focus (not all the way at the back)
  2. The LED must be in focus
  3. Therefore we must place the LED in the middle, where the focal point is
  4. The space behind the LED is wasted and podiums are expensive to make and may look dumb to consumers.
  5. Therefore we lop off the leftover, wasted reflector from behind the LED and get to skip making a podium. We also get a chance to reduce overall depth when doing this. Win-Win for the lame manufacturer.

That all seems to add up to me, but if you still don’t see what I’m saying maybe we can try and figure out where communication or logic is breaking down.


I have no reflector expertise or advanced understanding so perhaps thats the disconnect, if you cut off the podium and reflector thats behind it in the above pic would you not just end up with

the podium is gone, the flatspot is bigger (aka moved forward) and the reflector is now shorter?

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

chops728
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I have a Big light like this with the original 120w bulb —the new Olight M2x with a slight current bump out throws this beast and puts out more usable light—saves these for anchors or to remember what use to be—the one good thing mine has a 12v output on the side

wight
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Bort wrote:

I have no reflector expertise or advanced understanding so perhaps thats the disconnect, if you cut off the podium and reflector thats behind it in the above pic would you not just end up with

the podium is gone, the flatspot is bigger (aka moved forward) and the reflector is now shorter?
Right, that’s the only effect you would see. dchomack would not get different performance.

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

Bort
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wight wrote:
Bort wrote:

I have no reflector expertise or advanced understanding so perhaps thats the disconnect, if you cut off the podium and reflector thats behind it in the above pic would you not just end up with

the podium is gone, the flatspot is bigger (aka moved forward) and the reflector is now shorter?
Right, that’s the only effect you would see. dchomack would not get different performance.

So is pic number two ideal for throw, or should it be 100% cone from the LED to the tip

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

dchomak
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Here is the way I see it.
That reflector is optimized for the original Halogen bulb. The filament of that bulb is approximately at the focal point of the reflector (remember the filament is not at the base of the bulb but up, out into the reflector.

I verified that is the case when I found that my LED threw best when it was on that pedestal.
The makers of the light that is in the hardware store thought that looked funny, so they covered up the reflector space behind the LED with that flat shinny disc. The reflective coating on that disc serves no purpose for the LED as there is no light beamed in that direction from the LED.
On the other hand, the smaller reflective disc in my reflector did because in the case of the original halogen bulb, some light did get beamed backwards.

EDIT:
I am saying the same thing as wight, just expressing it a little differently.

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dchomak wrote:
Here is the way I see it.
That reflector is optimized for the original Halogen bulb. The filament of that bulb is approximately at the focal point of the reflector (remember the filament is not at the base of the bulb but up, out into the reflector.

I verified that is the case when I found that my LED threw best when it was on that pedestal.
The makers of the light that is in the hardware store thought that looked funny, so they covered up the reflector space behind the LED with that flat shinny disc. The reflective coating on that disc serves no purpose for the LED as there is no light beamed in that direction from the LED.
On the other hand, the smaller reflective disc in my reflector did because in the case of the original halogen bulb, some light did get beamed backwards.

EDIT:
I am saying the same thing as wight, just expressing it a little differently.


I understand what both of you are saying, i am asking if a light designed for LED for maximum throw, i would assume it needs a full cone starting from the LED to get maximum throw, and those shelves are there because they were adapted from halogen bulb reflectors (i used to own a halogen light not unlike your shelf retrofit light before XM-Ls and BLF were invented).
I am wondering what angle of reflector would give the most throw (assuming full cone gives max throw), and if bigger will make the hotspot smaller indefinitely or if its logarithmic, after say 8 inches (pulled out of a hat) the increase is minimal.

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

wight
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Bort wrote:
I understand what both of you are saying, i am asking if a light designed for LED for maximum throw, i would assume it needs a full cone starting from the LED to get maximum throw, and those shelves are there because they were adapted from halogen bulb reflectors (i used to own a halogen light not unlike your shelf retrofit light before XM-Ls and BLF were invented).
I am wondering what angle of reflector would give the most throw (assuming full cone gives max throw), and if bigger will make the hotspot smaller indefinitely or if its logarithmic, after say 8 inches (pulled out of a hat) the increase is minimal.
Fair enough. The problem that neither dchomak nor myself really mentioned was that the incan reflectors don’t actually have a focal point like an LED reflector would. (Or sometimes an LED reflector might have a focal ring.) They focus on a long area (the length of the incan filament ideally). When you put an LED in there it’s less ideal. I don’t have the world’s greatest grasp on exactly why at the moment. :~

I am not sure that you can characterize a reflector by looking at superficial things like the flat spot. Key differentiators are not visible just by eyeballing the thing. Note that some reflectors produce bad rings, or a larger hotspot, etc… all in the same size as one which produces no rings or a small hotspot. We can’t say “big diameter reflectors will have rings” or “deep reflectors automatically throw really well” or even “reflectors with a flat spot at the bottom are inferior”. The profile of the reflector together with it’s dimensions must be evaluated. (But bigger is better if everything else is good.)

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

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I don’t quite understand what focal point is.

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

wight
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Bort wrote:
I don’t quite understand what focal point is.
That’ll do it. Sorry I don’t have any great links handy! Actually this seems like a great way to demonstrate some aspects of what we are talking about: http://zeiss-campus.magnet.fsu.edu/tutorials/ellipticalreflectors/indexf...

Use the little flash demonstrator and move the “Light Source Shift” slider to see.. something. Heh. What I don’t have is a good link explaining why focusing on a single point is a terrible idea when the light is coming out of a much larger area than a single point. LED reflectors focus on something slightly bigger than a point. Incan reflectors focus on a big area to get the entire filament in decent focus.

Still fine, still on a break. One day I’ll catch up with you folks! previous wight catchup Wink
list of my drivers & variants (A17DD, FET+1 stuff, WIP stuff, etc)

Bort
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wight wrote:
Bort wrote:
I don’t quite understand what focal point is.
That’ll do it. Sorry I don’t have any great links handy! Actually this seems like a great way to demonstrate some aspects of what we are talking about: http://zeiss-campus.magnet.fsu.edu/tutorials/ellipticalreflectors/indexf...

Use the little flash demonstrator and move the “Light Source Shift” slider to see.. something. Heh. What I don’t have is a good link explaining why focusing on a single point is a terrible idea when the light is coming out of a much larger area than a single point. LED reflectors focus on something slightly bigger than a point. Incan reflectors focus on a big area to get the entire filament in decent focus.


Thanks for the link, i wonder what a 10 inch full cone same angle as a C8 reflector would do for throw

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"