Tecboy
Newly Enlightened
What is the difference between small head and big head of led flashlights? I noticed some small heads have the some amount of lumens at the big heads.
Small head vs. big head
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leon2245
Flashlight Enthusiast
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All else being equal (not optic vs. Reflector etc.), you can achieve a greater spot intensity with a deeper &/or larger diameter head. Yeah it does not affect overall output, lumens.
MAD777
Flashlight Enthusiast
Big head = more throw
Small head = more flood.
It's the same total amount of light (lumens), but one is a concentrated beam & the other is spread out over a larger area.
Neither is better than the other. Just different tools for different jobs.
Small head = more flood.
It's the same total amount of light (lumens), but one is a concentrated beam & the other is spread out over a larger area.
Neither is better than the other. Just different tools for different jobs.
StarHalo
Flashaholic
Bigger reflector = more light on the edges thrown forward = beam goes farther, a thrower
Smaller reflector = more light on the edges spills out = beam goes wider, a flooder
Smaller reflector = more light on the edges spills out = beam goes wider, a flooder
I do agree with bigger = better, but I am not sure I agree with the relationship between "Bigger reflector = more light on the edges thrown forward = beam goes farther, a thrower Smaller reflector = more light on the edges spills out = beam goes wider, a flooder"
Not having done the math but my Physics sense tells me:
It is a choice between the efficiency (light transmission efficiency vs light reflection efficiency) and practicality (cooling/assembly) of the reflector vs the refractor vs the dollar.
In a nut shell, larger head is more efficient but more expensive. Here is why:
To project a perfectly parallel beam (a constant size circle regardless of distance), the lens needs to be exactly one focal length from the "point source" emitter. But this math is complicated by the lens on the emitter itself (and it isn't a point but likely a square). So I would go with the mere Physics "sense" for now.
For an evenly distributed circle of light, a large reflector creates a larger "source" of light (make the emitter seem farther) allowing for longer focal length refractor (thinner lens). A smaller reflector will require a shorter focal length refractor (thicker lens). So, thinner "lens" with bigger reflector, vs thicker lens with small reflector. (Actually, it is not the thickness everywhere, but how convex it must be. So it is how much MORE thick the center must be vs edge thickness.)
Reflective is "free" (from efficiency standpoint). If your reflective material reflects 80% of the light, however big a reflector, each and every spot on the mirror you get 80% efficiency. The size does not affect efficiency.
Refractivity is expensive. The thicker your lens, the more light is lost as it passes the refractive (lens) material.
Common sense that price increase with size of mirror. Also, price of the lens increases more by diameter than it's increase due to thickness. In other words, a thick small lens is a lot cheaper than a thin big lens.
So, big=more expensive to make (beyond the cost of material) but should be more efficient.
Rick
Not having done the math but my Physics sense tells me:
It is a choice between the efficiency (light transmission efficiency vs light reflection efficiency) and practicality (cooling/assembly) of the reflector vs the refractor vs the dollar.
In a nut shell, larger head is more efficient but more expensive. Here is why:
To project a perfectly parallel beam (a constant size circle regardless of distance), the lens needs to be exactly one focal length from the "point source" emitter. But this math is complicated by the lens on the emitter itself (and it isn't a point but likely a square). So I would go with the mere Physics "sense" for now.
For an evenly distributed circle of light, a large reflector creates a larger "source" of light (make the emitter seem farther) allowing for longer focal length refractor (thinner lens). A smaller reflector will require a shorter focal length refractor (thicker lens). So, thinner "lens" with bigger reflector, vs thicker lens with small reflector. (Actually, it is not the thickness everywhere, but how convex it must be. So it is how much MORE thick the center must be vs edge thickness.)
Reflective is "free" (from efficiency standpoint). If your reflective material reflects 80% of the light, however big a reflector, each and every spot on the mirror you get 80% efficiency. The size does not affect efficiency.
Refractivity is expensive. The thicker your lens, the more light is lost as it passes the refractive (lens) material.
Common sense that price increase with size of mirror. Also, price of the lens increases more by diameter than it's increase due to thickness. In other words, a thick small lens is a lot cheaper than a thin big lens.
So, big=more expensive to make (beyond the cost of material) but should be more efficient.
Rick
ForrestChump
Flashlight Enthusiast
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Usually... more throw.
TeaSipper
Newly Enlightened
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Isn't the angle of the reflector cone rather than the size of the head determines the throw or the flood?
MAD777
Flashlight Enthusiast
You're correct in that the shape has to be designed for throw. If two reflectors are both perfectly designed for throw but one I bigger than the other, I believe the bigger one will win the throw contest.
TeaSipper
Newly Enlightened
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Right.
