This flashlight, as I envision it, doesn't exist yet. The idea for this light is inspired by the Kruithof Curve. The following is only a preliminary design. I hope we can discuss this flashlight and refine the concept. Hopefully, in time, someone better equipped and skilled than me will build a prototype.
This flashlight doesn't have any kind of hard specs, such as LED or battery type. It's centered around the idea that at higher brightness levels, we humans observe higher CCT light as "white" while at lower brightnesses we perceive lower CCT light as "white." In laymans terms, 500 lumens of 6000k light may appear white, but if you turn that light down to 5 lumens, it's going to seem quite blue. The reverse is also true. 5 lumens of 3500k light may seem white, but bump that brightness up significantly and it will appear yellowish.
The preliminary design of the flashlight is as follows: The flashlight has a main rotary knob (like mag mods that use the Shark driver and an external potentiometer) that controls brightness, CCT, and beam angle all SIMULTANEOUSLY. As the knob is turned clockwise, the flashlight gets brighter, cooler in color temp, and the beam narrows. The idea is that close up objects don't require as much light and a simultaneously wider beam angle to be seen. If engineered properly, such as light as this one could be a true all-in-one flashlight. Low, warm colored light in a nice flood for close up, medium brightness with medium color with a general purpose beam, and bright white throw would all be available with smooth, infinite variation in-between.
There have already been some adventurers into this arena, namely Data's Spy 007 Tri-V CPF, and McGizmo's LunaSol. While these lights are both impressive, the concept of the Kruithof flashlight implies a smooth and nearly infinitely-stepped transition of all three beam characteristics, without distinct modes that would "jolt" the user between differing states.
Here is a rough table that gives you an idea of how the three parameters would correlate to each other. I have no idea if the CCTs and beam angles I put down are appropriate for the corresponding flux levels. Testing and adjustment would be necessary.
flux CCT main beam divergence (not counting spill)
1000lm 6000k 4 degrees
250lm 5400k 6 degrees
100lm 5000k 10 degrees
25lm 4000k 12 degrees
5 lm 3500k 18 degrees
1 lm 3000k 25 degrees
0.1 lm 2900k 40 degrees
Of course, the current state of LED technology means that to create a flashlight like this would require multiple LEDs and the smooth switching between them in order to create a gradual shift from one color temperature to another. This alone may not be so difficult if the flashlight is large enough to accommodate 2-5 different color LEDs in the head, but the difficulty is compounded by ability to focus. To have the focusing take place at the same time as color and output variation, some kind of small electric motors would be required to move the secondary optics, be it TIR or traditional reflector, away from the LED.
The Kruithof Curve flashlight Generation 2 includes a laser ranging device (the laser should not be visible) built into the head that constantly monitors the distance to the target that the flashlight is being pointed at. In real time it smoothly and automatically adjusts the beam to compensate for changes in distance.
I find it interesting that this is one area where incandescents have a leg up on LEDs. With a regular filament, as you overdrive it, it naturally gets both brighter and higher in CCT at the same time. It's funny that an "obsolete" technology would be able to do natively what we have to engineer complex electronics to do with modern components.
This flashlight doesn't have any kind of hard specs, such as LED or battery type. It's centered around the idea that at higher brightness levels, we humans observe higher CCT light as "white" while at lower brightnesses we perceive lower CCT light as "white." In laymans terms, 500 lumens of 6000k light may appear white, but if you turn that light down to 5 lumens, it's going to seem quite blue. The reverse is also true. 5 lumens of 3500k light may seem white, but bump that brightness up significantly and it will appear yellowish.
The preliminary design of the flashlight is as follows: The flashlight has a main rotary knob (like mag mods that use the Shark driver and an external potentiometer) that controls brightness, CCT, and beam angle all SIMULTANEOUSLY. As the knob is turned clockwise, the flashlight gets brighter, cooler in color temp, and the beam narrows. The idea is that close up objects don't require as much light and a simultaneously wider beam angle to be seen. If engineered properly, such as light as this one could be a true all-in-one flashlight. Low, warm colored light in a nice flood for close up, medium brightness with medium color with a general purpose beam, and bright white throw would all be available with smooth, infinite variation in-between.
There have already been some adventurers into this arena, namely Data's Spy 007 Tri-V CPF, and McGizmo's LunaSol. While these lights are both impressive, the concept of the Kruithof flashlight implies a smooth and nearly infinitely-stepped transition of all three beam characteristics, without distinct modes that would "jolt" the user between differing states.
Here is a rough table that gives you an idea of how the three parameters would correlate to each other. I have no idea if the CCTs and beam angles I put down are appropriate for the corresponding flux levels. Testing and adjustment would be necessary.
flux CCT main beam divergence (not counting spill)
1000lm 6000k 4 degrees
250lm 5400k 6 degrees
100lm 5000k 10 degrees
25lm 4000k 12 degrees
5 lm 3500k 18 degrees
1 lm 3000k 25 degrees
0.1 lm 2900k 40 degrees
Of course, the current state of LED technology means that to create a flashlight like this would require multiple LEDs and the smooth switching between them in order to create a gradual shift from one color temperature to another. This alone may not be so difficult if the flashlight is large enough to accommodate 2-5 different color LEDs in the head, but the difficulty is compounded by ability to focus. To have the focusing take place at the same time as color and output variation, some kind of small electric motors would be required to move the secondary optics, be it TIR or traditional reflector, away from the LED.
The Kruithof Curve flashlight Generation 2 includes a laser ranging device (the laser should not be visible) built into the head that constantly monitors the distance to the target that the flashlight is being pointed at. In real time it smoothly and automatically adjusts the beam to compensate for changes in distance.
I find it interesting that this is one area where incandescents have a leg up on LEDs. With a regular filament, as you overdrive it, it naturally gets both brighter and higher in CCT at the same time. It's funny that an "obsolete" technology would be able to do natively what we have to engineer complex electronics to do with modern components.
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