【ツ】Interest check + ideas for a new multicolor flashlight

Lux Perpetua - I agree about the mixed optic being really versatile. I’m pretty sure Carclo doesn’t make one that way. However, the use could frost 3 of the 4 optics themselves, such as by sanding or with DC Fix. I think some people have had decent results also polishing a frosted Carclo.

If mixed at the same power level, the result will be white-ish, but likely with a strange tint. Maukka tested this with the color E17A’s:

In theory, by varying each channel individually, you could get one light to produce white of almost any CCT and DUV you wanted, within some really large limit.

But implementing that could complicated fast.

For now, would it be fair to say that a standard quad TIR is the leading option, with a mixed version being a bonus if such an option is identified?

Thank you for your feedback iamlucky13. Let’s see what Wurkkos and Sofirn can do in terms of drivers, emitters and optics.

I fully agree with you that using a standard optic like Carclo‘s 10624 (frosty wide spot) or Kathod‘s PL115140 30° 25mm wide beam optic (https://www.luxeonstar.com/assets/downloads/pl115140.pdf) would be the best way both in terms of best efficiency and modifiability. However, Sofirn may want to check for locally available Chinese optics (see Lumintop‘s plans for alternative, cheaper optic of the FW3A) to reduce prime costs as much as possible.

Eventually, a fully frosted optic might be a useful compromise even for the white LED? I’m not sure about the additional amber LED Wurkkos mentioned as fifth emitter before. It would also mean to find a whole different optic with a larger diameter.

I expect the biggest challenges for Sofirn in designing/sourcing an appropriate driver that can blend any desired color with RGB and is also capable to use more power for the white LED via separate channel. Once that is addressed, finding the right UI will be the next challenge which should be tested thoroughly by involvement of BLF (e.g. run a poll, build prototypes with different emitters and UI versions for testing).

Personally, I‘d like to see a powerful and efficient XP-L2 in this flashlight but HighCRI is highly anticipated nowadays and maybe a more wanted option.

If a quad optic will be chosen, the best is to find a well frosted one so that at least the colour blending is done well. It leaves white also very floody but people could choose to polish the part over the white cup. Most versatile would be a Carclo optic, so that people can swap it for another type of frosting if they like.

For a proper tint mixing the beams (spot and spill) of white and color LEDs should have the same shape and size - at any distance! This is difficult to achieve with XP-E color LEDs since they are smaller than a powerful white LED.
My RGBW D4 does a proper tint mixing at a distance of a couple of meters but it gets worse if you come closer.
I’ve just tested DC-Fix with this light. It helps a lot but the resulting beam is too floody for my taste.

Is there any variation of shape and size between the XP-E2 red, green and blue? I don’t think so but it would be nice to be absolutely sure. I only know that the output varies as blue and green can emit more lumens per Watt compared to red. Do you think peak temperatures will need to be taken into account when driving the XP-E2s with reasonable currents (< 1.5A)?

Do we need the white LED for color blending (RGBW) or will RGB only suffice?

If white is used separately only, do we still need to have a matching shape and size?

If this is the case, we should better stick to SST20 or LH351B as these are rather small in terms of dome and die size.

The shape and size are the same, and that causes a different beam because the diffraction of different colours on the surface of the led dome is a bit different.

The Luxeon C Colour Line is especially designed for colour mixing but the output is less than the XP-E.

Extra mixing option with the white led would be fun, but also complicates the user interface. Unless you go for a 4 button operation (separate ramping for each led).

Okay, so this is where we are right now, correct?

A quad emitter optic with frosty wide spot to diffuse the colorful beam as much as possible which hopefully helps blending infinite colors by mixing RGB.

So, a Carclo 10624 might be the right optic to start with in terms of prototyping.

@ Flashy Mike: Did you use the 10624 with your Emisar D4 or another one (10621/10622...)?

If that is a 10624 optic I wonder how much influence the diffraction of different colors have in accordance with the opacity of each single color LED, i.e. will spot and spill have the same size, intensity and appearance on a white wall, so they will look congruent when red, green and blue get overlaid?

If not, things might become even more complicated. Maybe there's also need for adjusting the current for each color LED individually to achieve a matching beam pattern? If blue for instance needs 0.5A for 100lm while red needs 0.75A for 100lm it could become challenging. Another aspect is that the reception of colors for the human eye is also dependent on the wavelength, i.e. green light will be noticed with much more intensity than red light at the same output level.

Maybe a stupid question…
What would happen if we use 4x RGBW led? So each color would be emited by 4 emiters?

Something like this...?

I'm afraid it would not create a uniform beam pattern as each color die is off-centered i.a.w. the optic's dome center position. OTOH, it would also increase costs dramatically as the Osram S2WP is quite expensive and so is the old XP-E Color, too.

You would also need modified led pcb’s (or a new one) to suit the RGB leds. In either case you could turn each led 90° to create a more uniform beam.

An optic for each colour gives the most uniform beam

I also did a colour zoomie once. Was much simpler UI in that one though.

With naked eye they appear very similar.

Depends on the body. My RGBW D4 takes 3.5 Amps with a pretty old 30Q and all 3 color LEDs at max (white LED off). The head ist too hot to hold after 2 minutes.

Don’t know - but you will see little lumens with RGB only.

The spot of my white LED (XP-G2) is larger than the color LEDs (XP-E2) spots. It mixes pretty nice with the color LEDs.

It is the stock D4 optics. With all LEDs on max the spot looks pretty nice but there are color artifacts around.

I wonder whether tint mixing is really required. I’d rather prefer a high CRI white LED, offered in diffferent flavours.

If it has a good to great user interface with options I’m in.

I’m in

The FiTorch MR35’s UI is a pita because you have to cycle through everything to get what you want. The old Quark RGB interface was better, but it was still a bit problematic because twisting the head for color change sometimes skipped colors; the contacts would get dirty and whatever. For this new light, I would really like to see one control for the off/on/intensity, preferably ramping… a magnetic ring would be peachy, I think. And a separate button control switch for the color selection. Not sure where to put hidden flashy modes, maybe on the ring somehow? The alternating blue/red strobe of the FiTorch is pretty cool, and I can imagine having a rapid-fire alternating of all the colors in succession as another mode.

All good points, although perhaps some of what has been done before can be leveraged. I don’t know if any of those I mentioned early in the thread would be of interest to the group, or if their designers would ok it, though.

If going with a custom driver, then I would say the high end ambition is an MCU capable of 5 channels of PWM. This would let the white channel be N+FET in order to provide a 7135 regulated low, but also be capable of high outputs, and to allow the color channels to be independently controlled.

So if there’s room in the host, for example, 2x7135 + FET and 3 more channels of 2x7135. One minor side benefit is the firmware could be tweaked to disable the FET, and the white LED replaced with another color (like amber or UV) if desired.

I started writing up a detailed concept for an Anduril-inspired UI, but I realized I got carried away and presumed somebody with more skill and time than me taking on a very ambitious project. I saved what I wrote, but am reluctant to post it since in retrospect, I think my expectations were unrealistic.

That's a good starting point. Can you overlay red green and blue without using the white LED?

Alright, the D4 host might in fact be too small to sustain long-term operation on high modes. Sofirn should better be using a host with better thermal dissipation specs.

Well, that's the trade off that comes with XP-E2 LEDs and a small host / head design. If we intended to use high performance color LEDs we would need a whole different host design and a much larger budget as these LEDs are very expensive (e.g. Osram Ostar Projection Compact LE R Q8WP for up to 700lm of red light @ 5A). Eventually, it would mean something in a size of a Q8. Another alternative would be using LEDIL ANNA optics with 2x XP-E2 for each color to double the output in an appropriate host like C8F/C8G with 21700 tube.

If I recall correctly, Hank is using the 10622 optic by default. Thus, using the much more floody 10624 could possibly eliminate those artifacts. Are you able to test your D4 with the 10624 optic instead?

Your input is highly appreciated. Thank you. It's good to know that we have a lot of resources and ideas in place already to make this project a story of success. For now, I'd say we wait for Wurkkos' and Sofirn's first feedback so see what they have in mind and how far they are willing to go in terms of custom-made drivers and hardware design. Maybe they can use one of their standard hosts (e.g. C8-design for LEDIL ANNA) or their new tint color mixing flashlight they just presented on Facebook. The latter one uses a quad optic already, so maybe that's common ground to start with. Due to holidays in China I don't expect any feedback from Sofirn or Wurkkos until beginning of next week.

I was a little unclear if anything specific plan is being worked on by Wurkkos or Sofirn or if they were waiting for input and a level of interest. If they are planning on sharing a concept, then excellent! I look forward to seeing it.

What is the tint-mixing flashlight? I haven’t seen anything about it. Is it Sofirn or Wurkkos? Sounds potentially very relevant.

Actually, the original idea of Wurkkos was to build a new colorful flashlight. As there are a lot of mediocre flashlights with colorful beams out there I recommended to involve the „BLF think tank“ to make this one special, unique and much more useful than any other colorful flashlight before. With Sofirn as their manufacturer in place the odds look promising that with joint efforts on all sides this project becomes successful.

However, I think we are right now in between both a plan of Wurkkos/Sofirn and a bunch of great ideas and concepts shared by experienced flashoholics and driver experts on BLF. As far as I have heard from Wurkkos the ideas presented so far were also well noticed and highly appreciated by Sofirn‘s management.

At this point of time I would like to find out:

  • what general concept Wurkkos and Sofirn want to focus on (optic design, color mixing, ...)
  • if Sofirn is capable to source appropriate components like high efficiency optics
  • if Sofirn is able to adopt the Dr Jones driver design or invent/develop something on their own
  • if we need to invest more efforts on giving them advices for the right driver design (e.g. linear/CC, buck, how many channels, ideal currents, etc.)
  • if they have any proprietary UI in mind already or if they need our support for a more sophisticated interface like a simplified, downsized Andúril

Concerning the tint mixing flashlight they seem to have revealed some information on Facebook and rost333 was so kind to share these news here on BLF...

Alright guys, I got some news from Sofirn (via Wurkkos)...

The goods news is, they are really interested in developing a colorful light, still not being really sure about their willingness to do a color-mixing flashlight. Wurkkos is definitely interested to go all the way to make this happen but it also depends on their manufacturer's approval and a proper proof of concept. The bad news is, Sofirn's engineer got somehow confused by the modified Emisar D4 of Flashy Mike.

He apparently assumed this is a commercially available version and then drew the conclusion to drop the idea of a comparable design. I will keep trying to convince them to stick with this idea as there is no such light in existence yet and because this is seems to be the most promising concept at all. Since I do not have direct contact to Sofirn's engineering team the (long) chain of communication is another obstacle to overcome.

Wurkkos has shown me a new "rectangular" host design Sofirn may want to use for an entire series of new flashlights. Their first draft of the colorful flashlight however seems to be something totally different which may be in contradiction to what we originally had in mind. This concept foresees that a quad array of XHP35 HD/HI LEDs will constitute the front beam while there will be RGBA LEDs used as some kind of side light. As they mix 12V LEDs with 3V LEDs they intend to use a buck-boost driver, so (depending on the battery configuration) the front array will probably be using a 4p1s boost circuit to drive the XHP35 LEDs whereas the the side LEDs are linked to a buck circuit. Not a bad idea so far as buck-boost drivers are more efficient and flexible than FET drivers.

For reasons of non-disclosure some information cannot be revealed yet. I was allowed to share this picture with you.

However, personally I don't think that using colorful LEDs on the side will cause as much interest as the original idea we talked about before. These LEDs would never create a matching beam pattern for infinite color mixing nor would their output yield any useful range without any optic. All you would get is a floody close-range illumination. I strongly suggested Wurkkos to convince Sofirn putting the colorful LEDs underneath the quad optic which should be frosty to create a wide spot beam without too many artifacts. I would also drop the amber LED and use RGBW only. Maybe using a 3V XP-L HD/HI instead of the 12V XHP35 HD/HI could save Sofirn some money and reduce the driver's complexity. I'm not sure about the feasibility of color mixing, though. This will become a real challenge and requires a lot of mutual cooperation between Sofirn's engineering and BLF members as well as lots of testing. Currently, the factory in Shenzhen is more than busy.

I think this rectangular design is quite innovative and handy. Hopefully, there will be enough time for prototype testing as beam quality, tactile handling and user interface are crucial factors for a successful new series of flashlights. I suggested Wurkkos to take some videos to show the prototype in operation and to understand the user interface.