Last I checked, daylight tends to be around 5500K mid-day, but it gets warmer in the morning and evening as the sun gets low in the sky. At sunrise/sunset it can be below 2000K. Moonlight tends to be around 4000K, but is generally too dim to activate cones for color perception.
This is correct.
The Kruithoff curve shows in what brightness range a specific CCT is perceived as comfortable. Sunlight with 5500K is comfortable because it is so bright! It also shows why cloudy days with very high CCTs and rather low brightness can seem uncomfortable.
Since lanterns usually produce floody light with low lux numbers, they need to have a low CCT <=3500K to be comfortable. A perfect lantern with a large brightness range would adjust its CCT with the brightness.
This is of course all somewhat independent of CRI. The CRI should be high regardless of the brightness and the tint should always be close to the BBL.
It would be an even more special project if the CCT changed continuously with ramping the brightness (sort of following the Kruithof curve) . It would require leds of two colour temperatures (say 2700K and 4500K) well blended in the beam, controlled by two separate pins of the MCU.
And a fair bit of programming and tuning a new ramping table.
It would be an even more special project if the CCT changed continuously with ramping the brightness (sort of following the Kruithof curve) . It would require leds of two colour temperatures (say 2700K and 4500K) well blended in the beam, controlled by two separate pins of the MCU.
And a fair bit of programming and tuning a new ramping table.
That would make a good option indeed for those who like to change the color tint for different used, but as you said would require more components and drive the price up for the lantern.
—
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
Here are 80CRI 3500K LEDs too if you want something warmer. They would also be even higher output than the 4000K 90CRI though I realize that isn’t needed in this lantern.
It would be an even more special project if the CCT changed continuously with ramping the brightness (sort of following the Kruithof curve) . It would require leds of two colour temperatures (say 2700K and 4500K) well blended in the beam, controlled by two separate pins of the MCU.
And a fair bit of programming and tuning a new ramping table.
That would make a good option indeed for those who like to change the color tint for different used, but as you said would require more components and drive the price up for the lantern.
Provided that a pin on the MCU is available, there is no extra components or higher price, it does require extra time from skilful BLF members.
No offense intended, but didn’t we kinda chat about this yesterday? Digikey carries 8 varieties of the LH351D that are available by the piece, but they don’t have any stock of the 90 CRI – those appear to be special order. It would be nice if they stocked those as well, though.
Either way… I personally feel that 80 CRI would be good enough for campground usage, but I’m definitely not a CRI snob and I don’t mean to spoil anyone’s fun that has an appetite for 90+ CRI.
It would be an even more special project if the CCT changed continuously with ramping the brightness (sort of following the Kruithof curve) . It would require leds of two colour temperatures (say 2700K and 4500K) well blended in the beam, controlled by two separate pins of the MCU.
And a fair bit of programming and tuning a new ramping table.
That would make a good option indeed for those who like to change the color tint for different used, but as you said would require more components and drive the price up for the lantern.
Provided that a pin on the MCU is available, there is no extra components or higher price, it does require extra time from skilful BLF members.
That’s probably pretty do-able. It could use 1×7135 for a warm tint and 3×7135 for a cool tint, or maybe 2 and 2, or 2 and 3, or something like that. If it’s intended to always be warm when low and cool when high, it wouldn’t even require any code changes — just a new ramp table.
Or it could do manual color temperature changes — a single ramp which splits into both emitter types based on a user-adjustable balance.
Or it might be possible to fit both.
If the hardware has two individually-controllable tints, I can find a way to make it work. The main questions are whether the idea is worth doing, and how exactly it should work.
It would be an even more special project if the CCT changed continuously with ramping the brightness (sort of following the Kruithof curve) . It would require leds of two colour temperatures (say 2700K and 4500K) well blended in the beam, controlled by two separate pins of the MCU.
And a fair bit of programming and tuning a new ramping table.
That would make a good option indeed for those who like to change the color tint for different used, but as you said would require more components and drive the price up for the lantern.
Provided that a pin on the MCU is available, there is no extra components or higher price, it does require extra time from skilful BLF members.
Creating the firmware and designing the board circuit is out of my capability range, but Toykeeper i believe can chime in on that idea. In this case a similar LED star as the Q8, but with pads for eight LEDs, with dual input paths for four each of 3000K & 4000K. (maybe we can get some of the other Q8 developers in on this project too. hints
—
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
That’s probably pretty do-able. It could use 1×7135 for a warm tint and 3×7135 for a cool tint, or maybe 2 and 2, or 2 and 3, or something like that. If it’s intended to always be warm when low and cool when high, it wouldn’t even require any code changes — just a new ramp table.
Or it could do manual color temperature changes — a single ramp which splits into both emitter types based on a user-adjustable balance.
Or it might be possible to fit both.
If the hardware has two individually-controllable tints, I can find a way to make it work. The main questions are whether the idea is worth doing, and how exactly it should work.
Interesting ideas definitely.
—
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
similar LED star as the Q8, but with pads for eight LEDs, with dual input paths for four each of 3000K & 4000K.
Is the lantern originally designed for two LEDs? If so, a two-color design should be feasible with four total emitters. Or if there’s too much angular shift with two of each, maybe it could do three of each? I doubt four of each would be needed, especially at the low levels the lantern is running at.
If it has two tints, I’d suggest doing ~3000K and ~5000K, or if they’re available, perhaps even warmer than 3000K.
If user-adjustable color is desired it may also be worth increasing the total number of 7135 chips, so it can reach the original brightness target at any tint. That will move the levels a bit farther apart at the low end, so the bottom end of the ramp won’t be as smooth, but it’ll probably be fine.
similar LED star as the Q8, but with pads for eight LEDs, with dual input paths for four each of 3000K & 4000K.
Is the lantern originally designed for two LEDs? If so, a two-color design should be feasible with four total emitters. Or if there’s too much angular shift with two of each, maybe it could do three of each? I doubt four of each would be needed, especially at the low levels the lantern is running at.
If it has two tints, I’d suggest doing ~3000K and ~5000K, or if they’re available, perhaps even warmer than 3000K.
If user-adjustable color is desired it may also be worth increasing the total number of 7135 chips, so it can reach the original brightness target at any tint. That will move the levels a bit farther apart at the low end, so the bottom end of the ramp won’t be as smooth, but it’ll probably be fine.
Since i am using the Q8 star in the V2 prototype, it now has four LEDs. Right now I plan to increase the number of the main 7135s to four (for 1.4 amps max) next week after the first field testing with the three , ( + the original one already on the driver for the low modes.
—
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
Both itsme and flashycali added for a second. Not sure why, but the second link posted by itsme does not work right, but the link in my post above does, as do the ones in this post.
The list by number or name? I am guessing the one by name.
Both. When i copy form google docs to a .rtf file, is spaces them twice, and cant get them to consolidate to a single line for each number as it is in the list in the OP.
—
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
Ok, send you both files in a few different formats, guessing the MHTML might be the best to try first. Here is what that one looks like when I post it, I am using Chrome, and I need to use the advanced post editor or else it gets all scrunched together.
By number:
1 DBSAR
2 DBSAR
3 DBSAR
4 DBSAR
5 DBSAR
6 SaniPE
7 brad
8 Gunga
9 Andyman
10 emarkd
11 chuckhov
By user name
User Name
Quantity
Entry number
18sixfifty
1
72
808Hi
5
582, 609, 651-653
a_idoux
1
779
Aardvark
1
48
Aardvark Spleen
2
127, 128
Abe87
4
154, 367-369
acml
1
113
adrn77
1
667
adsum
1
276
—
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
i have seen this project right now.
if it is possible: im very interested depending on price
This is correct.
The Kruithoff curve shows in what brightness range a specific CCT is perceived as comfortable. Sunlight with 5500K is comfortable because it is so bright! It also shows why cloudy days with very high CCTs and rather low brightness can seem uncomfortable.
Since lanterns usually produce floody light with low lux numbers, they need to have a low CCT <=3500K to be comfortable. A perfect lantern with a large brightness range would adjust its CCT with the brightness.
This is of course all somewhat independent of CRI. The CRI should be high regardless of the brightness and the tint should always be close to the BBL.
Project Excalibur - Next Generation LED Thrower (UPDATE 2018-01-15: 1.7Mcd)
Portable Thrower Comparison
Great information on CRI
So will their be a test
Great work by all on this project.
Thank You very much.
I thought CRI had more to do with the visible spectrum and nothing to do with color temperature or sunlight…
Find all my reviews of flashlights and more gear at www.bmengineer.com
please count me in (interested)
Just a simple man.
It would be an even more special project if the CCT changed continuously with ramping the brightness (sort of following the Kruithof curve) . It would require leds of two colour temperatures (say 2700K and 4500K) well blended in the beam, controlled by two separate pins of the MCU.
And a fair bit of programming and tuning a new ramping table.
link to djozz tests
Please put me down for 1
added to interest list for 1 each bobkido, and ulfm1, added a second lantern for Bill63 (#425, 778)
interest list sorted by entry number
interest list sorted by user names
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
That would make a good option indeed for those who like to change the color tint for different used, but as you said would require more components and drive the price up for the lantern.
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
https://www.digikey.com/product-detail/en/samsung-semiconductor-inc/SPHW...
Here are 80CRI 3500K LEDs too if you want something warmer. They would also be even higher output than the 4000K 90CRI though I realize that isn’t needed in this lantern.
Provided that a pin on the MCU is available, there is no extra components or higher price, it does require extra time from skilful BLF members.
link to djozz tests
GUYS, GUYS.
I found a source for LH351D in America!
Here it is the list if you want:
https://www.digikey.ca/products/en?keywords=SPHWHTL3DA0GF4
Here is 5000k 90+CRI:
https://www.digikey.ca/product-detail/en/samsung-semiconductor-inc/SPHWH...
Here is 4000k 90+CRI:
https://www.digikey.ca/product-detail/en/samsung-semiconductor-inc/SPHWH...
Here is 3500k 90+CRI:
https://www.digikey.ca/product-detail/en/samsung-semiconductor-inc/SPHWH...
2700k 90+CRI:
https://www.digikey.ca/product-detail/en/samsung-semiconductor-inc/SPHWH...
Not all available immediately though. A group buy would be extremely interesting if I could buy at least a reel of it. Anyone want to take part in it?
My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547
No offense intended, but didn’t we kinda chat about this yesterday? Digikey carries 8 varieties of the LH351D that are available by the piece, but they don’t have any stock of the 90 CRI – those appear to be special order. It would be nice if they stocked those as well, though.
Either way… I personally feel that 80 CRI would be good enough for campground usage, but I’m definitely not a CRI snob and I don’t mean to spoil anyone’s fun that has an appetite for 90+ CRI.
Oh, I didn’t understand. Sorry too if I offended you too.
To get different colors LH351D emitters though, we could start a group buy. However, I doubt we could buy 800 of them though.
The only ones that are on offer from Digikey right away are the 5000k and 2700k.
I could send 2700k LH351Ds to test them out, and see if they are more efficient that the small die LH351Bs 3000k 90CRI+.
My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547
No sweat. And thats weird, I’m showing 8 of them total, with 4 of them being 80CRI:
3000K 3500K 4000K 5000K
That’s probably pretty do-able. It could use 1×7135 for a warm tint and 3×7135 for a cool tint, or maybe 2 and 2, or 2 and 3, or something like that. If it’s intended to always be warm when low and cool when high, it wouldn’t even require any code changes — just a new ramp table.
Or it could do manual color temperature changes — a single ramp which splits into both emitter types based on a user-adjustable balance.
Or it might be possible to fit both.
If the hardware has two individually-controllable tints, I can find a way to make it work. The main questions are whether the idea is worth doing, and how exactly it should work.
Creating the firmware and designing the board circuit is out of my capability range, but Toykeeper i believe can chime in on that idea. In this case a similar LED star as the Q8, but with pads for eight LEDs, with dual input paths for four each of 3000K & 4000K. (maybe we can get some of the other Q8 developers in on this project too. hints
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
Interesting ideas definitely.
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
Is the lantern originally designed for two LEDs? If so, a two-color design should be feasible with four total emitters. Or if there’s too much angular shift with two of each, maybe it could do three of each? I doubt four of each would be needed, especially at the low levels the lantern is running at.
If it has two tints, I’d suggest doing ~3000K and ~5000K, or if they’re available, perhaps even warmer than 3000K.
If user-adjustable color is desired it may also be worth increasing the total number of 7135 chips, so it can reach the original brightness target at any tint. That will move the levels a bit farther apart at the low end, so the bottom end of the ramp won’t be as smooth, but it’ll probably be fine.
I am interested! Please put me down for 1.
Since i am using the Q8 star in the V2 prototype, it now has four LEDs. Right now I plan to increase the number of the main 7135s to four (for 1.4 amps max) next week after the first field testing with the three , ( + the original one already on the driver for the low modes.
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
I added you at number 779 on the interest list
interest list sorted by entry number
interest list sorted by user names
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
interest list sorted by entry number
interest list sorted by user names
Can you please add me for a second unit. Itsme #626
Thanks
Just spoke to my friend and he wants one too so please put me down for one more making it a total of 2 for me, thanks!
For some reason its double-spacing each line, and can’t get it to consolidate to single-line list like the OP has, to update the OP.
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
Both itsme and flashycali added for a second. Not sure why, but the second link posted by itsme does not work right, but the link in my post above does, as do the ones in this post.
interest list sorted by entry number
interest list sorted by user names
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
The list by number or name? I am guessing the one by name.
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
Both. When i copy form google docs to a .rtf file, is spaces them twice, and cant get them to consolidate to a single line for each number as it is in the list in the OP.
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
Ok, send you both files in a few different formats, guessing the MHTML might be the best to try first. Here is what that one looks like when I post it, I am using Chrome, and I need to use the advanced post editor or else it gets all scrunched together.
By number:
1 DBSAR
2 DBSAR
3 DBSAR
4 DBSAR
5 DBSAR
6 SaniPE
7 brad
8 Gunga
9 Andyman
10 emarkd
11 chuckhov
By user name
User Name
Quantity
Entry number
18sixfifty
1
72
808Hi
5
582, 609, 651-653
a_idoux
1
779
Aardvark
1
48
Aardvark Spleen
2
127, 128
Abe87
4
154, 367-369
acml
1
113
adrn77
1
667
adsum
1
276
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
Definitely interested.
This is an overdue project.
Pages