3 ms·

If not banned outright, they should at least be required to use a 1MHz minimum frequency.

Zak 9y ago
10 or 20 kHz would probably be sufficient, based on talking with the author of some of the most used open-source flashlight driver firmwares, who is quite sensitive to PWM.
- walterbell 9y ago
  Which flashlights use this firmware?
  - Zak 9y ago
    These are all enthusiast-oriented, not something you'd find in a retail store. At least one can only be ordered through a group buy on budgetlightforum.com right now, though a retail offering will come in the future. * BLF A6 (AKA Astrolux S1) * Astrolux S41/Manker E14 * BLF X5/X6 (AKA Astrolux S2/S3/SS) * Emisar D4, D1, D1S * BLF Q8 * BLF GT * Convoy S2+/C8 (new firmware version) These don't all use the same firmware, but they all use an open-source firmware with high-frequency PWM, except that I think the BLF GT does not use PWM. A number of expensive custom lights use these too; those often focus on metalworking and exotic materials. Firmware sources available here: http://bazaar.launchpad.net/~toykeeper/flashlight-firmware/trunk/files/head:/ http://bazaar.launchpad.net/~toykeeper/flashlight-firmware/t... I own an Astrolux S41 (Nichia 219B), Astrolux SS (3A) and a semi-custom light I assembled using the A6 and Biscotti firmwares by ToyKeeper. I plan to pick up the Emisar D4 (Nichia 219C) and D1S (5D).
    - walterbell 9y ago
      Thanks! I’ve been looking at [1] low-flicker, daylight simulation LED lights that can output 10K LUX. Great to hear that OSS firmware exists for some PWM lighting. [1] https://www.aputure.com/products/al528-1 https://www.aputure.com/products/al528-1
      - Zak 9y ago
        > that can output 10K LUX What does this mean? I would assume the surface brightness of the emitters is a good bit higher than that. Aside from surface brightness, lux does not provide any information about a light source without a distance. The SI unit of luminous flux is the lumen, and luminous intensity, the candela. I have a Viltrox panel with similar characteristics, but smaller (adjustable color temperature, CRI 95+) and I think it uses 5mm Yujis. Brightness adjustment is non-PWM. It's also meant to take a camera battery, but I converted it to use two loose 18650s. Model VL162T, $30ish on Amazon.
        walterbell 9y ago
        The Aputure 528S is rated at 12700 lux at 50 cm. Will check out the Viltrox, thanks.
        Zak 9y ago
        I see on the specs page it's 4380 lux at 1 meter, or 4380 candela. No information is offered on total output, but it's possible to estimate from the information given. Lux is lumens per square meter. Candela is lumens per steradian, the SI unit of solid angle. At one meter, these are equal, unless the beam hasn't converged at 1 meter. Aputure provides the beam angle in degrees, for which it was surprisingly hard to find the conversion. Sure, the units aren't technically comparable, but we know they meant the apex plane angle, at least we do now that I looked up the correct term. So a right circular cone (which the light produced by a rectangular panel isn't, but we'll pretend) with an apex plane angle of 25 degrees has a solid angle of 0.1489365798 sr, approximately. 4380 lm/sr / 0.1489365798 sr = 29408 lm. And that can't be right because the power consumption is 30 W, and the theoretical limit of luminous efficacy is 683 lm/W. I'd expect an LED panel like this to be on the order of 100 lm/W for about 3000 lm from 30 W.

Zak 9y ago

10 or 20 kHz would probably be sufficient, based on talking with the author of some of the most used open-source flashlight driver firmwares, who is quite sensitive to PWM.

walterbell 9y ago
Which flashlights use this firmware?
- Zak 9y ago
  These are all enthusiast-oriented, not something you'd find in a retail store. At least one can only be ordered through a group buy on budgetlightforum.com right now, though a retail offering will come in the future. * BLF A6 (AKA Astrolux S1) * Astrolux S41/Manker E14 * BLF X5/X6 (AKA Astrolux S2/S3/SS) * Emisar D4, D1, D1S * BLF Q8 * BLF GT * Convoy S2+/C8 (new firmware version) These don't all use the same firmware, but they all use an open-source firmware with high-frequency PWM, except that I think the BLF GT does not use PWM. A number of expensive custom lights use these too; those often focus on metalworking and exotic materials. Firmware sources available here: http://bazaar.launchpad.net/~toykeeper/flashlight-firmware/trunk/files/head:/ http://bazaar.launchpad.net/~toykeeper/flashlight-firmware/t... I own an Astrolux S41 (Nichia 219B), Astrolux SS (3A) and a semi-custom light I assembled using the A6 and Biscotti firmwares by ToyKeeper. I plan to pick up the Emisar D4 (Nichia 219C) and D1S (5D).
  - walterbell 9y ago
    Thanks! I’ve been looking at [1] low-flicker, daylight simulation LED lights that can output 10K LUX. Great to hear that OSS firmware exists for some PWM lighting. [1] https://www.aputure.com/products/al528-1 https://www.aputure.com/products/al528-1
    - Zak 9y ago
      > that can output 10K LUX What does this mean? I would assume the surface brightness of the emitters is a good bit higher than that. Aside from surface brightness, lux does not provide any information about a light source without a distance. The SI unit of luminous flux is the lumen, and luminous intensity, the candela. I have a Viltrox panel with similar characteristics, but smaller (adjustable color temperature, CRI 95+) and I think it uses 5mm Yujis. Brightness adjustment is non-PWM. It's also meant to take a camera battery, but I converted it to use two loose 18650s. Model VL162T, $30ish on Amazon.
      - walterbell 9y ago
        The Aputure 528S is rated at 12700 lux at 50 cm. Will check out the Viltrox, thanks.
        Zak 9y ago
        I see on the specs page it's 4380 lux at 1 meter, or 4380 candela. No information is offered on total output, but it's possible to estimate from the information given. Lux is lumens per square meter. Candela is lumens per steradian, the SI unit of solid angle. At one meter, these are equal, unless the beam hasn't converged at 1 meter. Aputure provides the beam angle in degrees, for which it was surprisingly hard to find the conversion. Sure, the units aren't technically comparable, but we know they meant the apex plane angle, at least we do now that I looked up the correct term. So a right circular cone (which the light produced by a rectangular panel isn't, but we'll pretend) with an apex plane angle of 25 degrees has a solid angle of 0.1489365798 sr, approximately. 4380 lm/sr / 0.1489365798 sr = 29408 lm. And that can't be right because the power consumption is 30 W, and the theoretical limit of luminous efficacy is 683 lm/W. I'd expect an LED panel like this to be on the order of 100 lm/W for about 3000 lm from 30 W.