Making the LT1 Warmer than 2700k

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Ranger-H
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Making the LT1 Warmer than 2700k

Hi All,

I love my BLF LT1 but found the 2700k not quite warm enough to give that classic candlelight atmosphere. I felt this was a real shame because the realism of the candlelight mode flicker is impressive. I’m hoping the LT1 Mini might be able to warm things up a bit, which would make it the best hiking/camping candle in existence.

Interestingly, 2700k seems to be an industry limit on the warmth of LED lamps so we tried to find some warmer LEDs to replace the 4 Samsung 2700k ones in the LT1.

Interestingly, we weren’t able to find any warmer LEDs with the equivalent or similar spec. Undeterred, my friend Joss and I set about warming up the lamp with a CTO 1/2 (50%) orange lighting gel. I don’t like the full 5000k cold white light and would never use it. With the CTO 1/2 I estimate it changes the range from around 4000k to 1700k. Some may prefer to use a CTO 1/4 (25%) orange gel, which would probably be 4500k to 2200k.

I work as a national park ranger in Zimbabwe and anything above 3000k is a magnet for insects and gives away our position miles away.

Here are a few snaps of the process and the result in case anyone else wants to do the mod.

Regards

Mark Hiley



Instructions:

https://drive.google.com/file/d/1LAytgz_jn9D8Rrt3DHYkFkupo16Gv_UC/view?u...

Before you can start you need to unscrew the board in order to untwist the loosen the wires to enable you to lift off the top far enough to access inside the diffuser.

https://drive.google.com/file/d/1-WBq3YuzpkiDvxoo0TdAMLQu485eQSwm/view?u...

The template is roughly 92mm at the widest part and 54mm top to bottom. The curve is rough by hand.

https://drive.google.com/file/d/1HdbxZhVAtYxLLelSExDCrQS3hdykPrPA/view?u...

https://drive.google.com/file/d/1z52MSuuS0K4zNY5XdnRqT9e1MeqePB3p/view?u...

https://drive.google.com/file/d/1xGj-y1EQAaQkC0zYxVdS0xEZKgJ9Y55d/view?u...

Once it’s in, we used a couple of small pieces of sellotape to hold it but the shape actually holds it in place.

Here’s the end result

https://drive.google.com/file/d/1CPF8K1-W23XT-3gNvCtxAX09TURn0Wvv/view?u...

Big_Sam
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That’s a useful mod for your application, I guess there is a limit to how far you can push a ‘white’ led in the colour temp range before you just need to get an amber led? Would changing to Red LEDs be a useful mod? Or change the cool white ones for Red ones?

Agro
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One relevant topic, it lists known LEDs with low CCTs. Sadly no direct swap to LT1:
http://budgetlightforum.com/node/66421

iamlucky13
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Good thinking. I’ve actually been intending to cut myself a set of wrap around filters for my LT1 to put on the outside when desired using rubber bands.

If there is interest in something more advanced:

One option would be to replace the 5000K LED’s with amber or red LED’s. XP-E2 and SST-20DR are both compatible with the PCB, and I don’t think the driver would have any

Then you would ramp between warm white and the color.

Another option would be more of a hack: buy multiple of the smaller E17A or E21A boards from Eurekatronix (looks like Clemence is not ready to accept orders through the new site yet, though), and either add new holes to the top of the LT1 to screw those in place with or use thermal adhesive to secure them. There will be a fair amount of soldering to link them all together, but then you could select any pair of color temperatures that Clemence sells.

Personally, I’d love to see Clemence make dedicated LT1 board. Since this is a low performance light, the cost could be kept low by making it from aluminum with a conventional dielectric layer.

jon_slider
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> I work as a national park ranger in Zimbabwe and anything above 3000k is a magnet for insects and gives away our position miles away.

thanks for sharing your application, I find that very interesting

another way to lower the Color Temperature by about 500 CCT, is by slicing the dome off the LEDs.

That would bring your 2700k LEDs down to about 2200k

I cant find a photo of a shaved next to unshaved atm, but comparing to a 219B 3000k may help you visualize the shaved 2700k:

in this next photo you can see a shaved 3500k is almost identical to 3000k (just to illustrate the point that shaving drops CCT by 500k):

Rexlion
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> I work as a national park ranger in Zimbabwe and anything above 3000k is a magnet for insects and gives away our position miles away.

Hmm, never thought about it before, but that makes perfect sense. If the light from a fire were attractive to insects, the flying buggers might have died out long ago from flying into campfires and wildfires.

== We save the planet from darkness ==

Ranger-H
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good point! I believe that many insects have limited colour spectrum and are ‘blind’ to the warm fire colours. Perhaps natural selection had a hand in that after all those with wider spectrum burned to death, as you say!

Ranger-H
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Just ordered a Fireflies Nov-Mu with Nichia E21A R9050 2000K option, to see how it is as a mini LT1. It comes with a diffuser and anduril, which should give the same realistic candle flicker. The run-times should be similar to LT1 so perhaps it will make it redundant!

Best interested to know if anyone has one of these as I can’t find any photos or anything on YouTube.

https://www.ff-light.com/index.php?route=product/product&product_id=77

Ranger-H
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That’s really interesting Jon, thanks! That could have saved us a lot of trouble! So the 2700k Samsungs are amber LEDs with a cooling layer to make them 2700k?

jon_slider
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Ranger-H wrote:
photos or anything

Google says
(click on Images)

and

YouTube says

RobertB
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Big_Sam wrote:
That’s a useful mod for your application, I guess there is a limit to how far you can push a ‘white’ led in the colour temp range before you just need to get an amber led? Would changing to Red LEDs be a useful mod? Or change the cool white ones for Red ones?

Bingo. They should have had a model with warm white and red LED’s, since it was supposed to be a camp lantern in the first place. Red light doesn’t attract the bugs. White light does. Amber light doesn’t attract as many bugs, but still attracts them. IMO, all the blinky stuff is pretty useless too. If I want a candle flickering, I’ll light a candle.

SunLike
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Many peoples asked about 2200k and etc. By I still have no received order for 2700k+660nm Facepalm

I mean who ordered pcb for LT1 HERE

BelMORDOR’s Ламповщик|Lampman
https://t.me/sunlikenews

DBSAR
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What i been finding from trial & error, experimentation, etc. that the 351 LED in 2700K is the balanced limit for a good high-CRI warm white. A candle flame is around the 1500K to 2100K color temp range, (usually at about 1800K in the Blackbody scale range) And very hard to achieve with LEDs sustaining a high-CRI like what a candle does.

That Canadian flashlight guy & Lantern Guru -Den / DBSARlight