Emitter swap and output differences using same stock driver?

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lg.tech
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Emitter swap and output differences using same stock driver?

I have an old Nitecore MT2C which has an XP-G R5 emitter that I would like to swap for a high CRI emitter with a cct between 3500-4000k, probably SST20 or Nichia 219C, or even LH351D (if it can fit the opening in the reflector).
Now my question is, related to the vf and current of those emitters compared to the stock XP-G R5 using the stock driver, will I lose output and if so, how much? Or will I even possibly gain output considering these newer emitters are more efficient than the old XP-G?

Edited by: lg.tech on 04/01/2021 - 20:52
CNCman
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Welcome to BLF Cool

jon_slider
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> will I lose output and if so, how much?
… XP-G?

yes you will lose output the warmer you go:

Nitecore ex11.2
w stock XP-G R5
max 145

219b 4500k 9080
max 138
5% less bright than xpg

shaved 2700k lh351d
max 116
20% less bright than xpg

219b 3000k 9080
max 106
27% less bright than xpg

===
however, I dont care about losing lumens, I dont run my lights on maximum
and fwiw, a 50% change in lumens is a small visual step.. the 5-30% percent changes listed above are not visually noticeable

The 30% increase in CRI is very significant in terms of Light Quality,
and is well worth the insignificant reduction in Light Quantity

good luck with your mods Smile

lg.tech
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CNCman wrote:
Welcome to BLF Cool

Thank you!
lg.tech
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jon_slider wrote:
> will I lose output and if so, how much?
… XP-G?

yes you will lose output the warmer you go:

Nitecore ex11.2
w stock XP-G R5
max 145

219b 4500k 9080
max 138
5% less bright than xpg

shaved 2700k lh351d
max 116
20% less bright than xpg

219b 3000k 9080
max 106
27% less bright than xpg

===
however, I dont care about losing lumens, I dont run my lights on maximum
and fwiw, a 50% change in lumens is a small visual step.. the 5-30% percent changes listed above are not visually noticeable

The 30% increase in CRI is very significant in terms of Light Quality,
and is well worth the insignificant reduction in Light Quantity

good luck with your mods Smile


I know the lower cct will have a lower output, I was just hoping the loss would be small considering the newer emitters are more efficient and also considering this isn’t a powerful light (compared to most newer ones).

I’m mostly interested about light quality as well and hardly ever need high output since most of my usage is indoors.

My other lights are Nitecore EC25 Cobra and Jaxman E3 with Nichia 219C 4000k. Ever since I got the E3 about 2 years ago I hardly ever touch the EC25, the tint on the XML emitter looks terrible by comparison.
My first real light was a Nitecore D11, which died a few years ago after an accidental drop, I loved that light and would still be rocking it with a nice 219C emitter today if I hadn’t died. Also had a 4Sevens Quark 123 as a keychain light for a number of years.
The MT2C still sees regular use but I hate the forward clicky switch on it that skips levels even if you just look at it wrong and the UI with the blinky modes. Despite this I still like this light and if I could swap the emitter for something warmer, specially something like the LH351D 3500k (floodier) I would use it so much more.
Speaking of the switch, are there any reverse clicky switches with the same dimensions as a forward switch?

jon_slider
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lg.tech wrote:
I was just hoping the loss would be small

the loss IS small Smile

forget about efficiency, thats a red herring and only favors Low CRI and Green Tint.

efficiency concerns escape me, since I use rechargeable batteries.

worrying about efficiency is a bit like worrying about gas mileage when choosing car tires. The tire with the hardest rubber and smoothest tread, is the most efficient on smooth dry pavement, but, hard smooth tires are terrible in rain, snow, and dirt.

Here are some comparisons of Low CRI LED color to High CRI swaps:

Low CRI Neutral White XM-L:

High CRI 219b 4500k 9080 sw45k:

Sunwayman V11r:
219b sw45k on the left, stock NW XM-L LED on the right:

Sunwayman V11r with 219b 3000k 9080 sw30

High CRI 219b 4500k 9080 sw45k and High CRI 219b 3000k

V11r w LH351d 3500k:

the LH351d does make a larger hotspot, and more lumens than 219b, but has greener tint than 219b:

This is the spectrum of a High Output Low CRI LED, notice the Red output is negative:

compare to a High CRI 219b:

an LH351d has less Red output:

similar to a 219c:

here is an SST, it has excellent Red output, but Green Tint
Tint is the DUV value:

difference in Tint, between negative DUV and Positive DUV:

hope the pics are useful Smile

EasyB
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lg.tech wrote:

I know the lower cct will have a lower output, I was just hoping the loss would be small considering the newer emitters are more efficient and also considering this isn’t a powerful light (compared to most newer ones).

Yes, new emitters are more efficient so I think you could end up with a similar or a net gain in output depending on what emitter you choose.

Some estimate numbers:
See here for some relevant tests from djozz.
https://budgetlightforum.com/node/40133

He tests an R5 XPG2 but the output should be close to an R5 XPG according to cree datasheets. You can see some high cri emitters in that test. From looking at maukka’s test of the sst20 below it looks like the output is similar to the R5 XPG2.
https://budgetlightforum.com/node/62195

lg.tech
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jon_slider wrote:
lg.tech wrote:
I was just hoping the loss would be small

the loss IS small Smile

forget about efficiency, thats a red herring and only favors Low CRI and Green Tint.

efficiency concerns escape me, since I use rechargeable batteries.

worrying about efficiency is a bit like worrying about gas mileage when choosing car tires. The tire with the hardest rubber and smoothest tread, is the most efficient on smooth dry pavement, but, hard smooth tires are terrible in rain, snow, and dirt.

Here are some comparisons of Low CRI LED color to High CRI swaps:

Low CRI Neutral White XM-L:

High CRI 219b 4500k 9080 sw45k:

Sunwayman V11r:
219b sw45k on the left, stock NW XM-L LED on the right:

Sunwayman V11r with 219b 3000k 9080 sw30

High CRI 219b 4500k 9080 sw45k and High CRI 219b 3000k

V11r w LH351d 3500k:

the LH351d does make a larger hotspot, and more lumens than 219b, but has greener tint than 219b:

This is the spectrum of a High Output Low CRI LED, notice the Red output is negative:

compare to a High CRI 219b:

an LH351d has less Red output:

similar to a 219c:

here is an SST, it has excellent Red output, but Green Tint
Tint is the DUV value:

difference in Tint, between negative DUV and Positive DUV:

hope the pics are useful Smile


The 219B is an old emitter which is also no longer made as far as I know. I personally don’t like the “rosier” tint compared to the 219C 4000k from my Jaxman E3, this rosier tint doesn’t look very natural imho.
lg.tech
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EasyB wrote:
lg.tech wrote:

I know the lower cct will have a lower output, I was just hoping the loss would be small considering the newer emitters are more efficient and also considering this isn’t a powerful light (compared to most newer ones).

Yes, new emitters are more efficient so I think you could end up with a similar or a net gain in output depending on what emitter you choose.

Some estimate numbers:
See here for some relevant tests from djozz.
https://budgetlightforum.com/node/40133

He tests an R5 XPG2 but the output should be close to an R5 XPG according to cree datasheets. You can see some high cri emitters in that test. From looking at maukka’s test of the sst20 below it looks like the output is similar to the R5 XPG2.
https://budgetlightforum.com/node/62195


That’s what I’m hoping, since this is a relatively low output light, (compared to most modern lights today), it would be nice if I could swap the emitter to a high CRI emitter while keeping similar OTF output.
I think I’ll probably end up going with the 219C 4000k. 3500k would be my preference but I haven’t seen any 219C’s with that cct.
The SST20 is too throwy, most of my use is indoor so flood is preferable.
The LH351D has the cct I want but I don’t know if it would fit in the reflector opening.

Thank you!

jon_slider
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lg.tech wrote:
The LH351D has the cct I want but I don’t know if it would fit in the reflector opening.

yes, it will fit
xpg, 219b, and LH351d are all built onto the same 3535 standard size footprint:

I calculate the 3500k LH351d will be only 4% less bright than the stock cool white XPG. This is not a visible difference.

you might also want to try a 5000k LH351d. It should be 27% brighter than the XPG, though that is only a barely visible difference. Try both Smile

in the next photo, on the left is your Nitecore.. note the entire footprint of the LED is visible in the reflector opening.. it will be the same for the LH351d (larger dome, but not larger footprint)

on the right, I pasted the LH351d image onto the Nitecore reflector so you can visualize the difference:

it is not expensive to find out
here is a source for a 3500k LH351d

note you can buy the LED already installed on an mcpcb, and you can test fit the reflector over the new LED before removing the original LED..

I hope you measure the change in output before and after, in your actual light, and post your results…

good luck with the mod

lg.tech
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jon_slider wrote:
lg.tech wrote:
The LH351D has the cct I want but I don’t know if it would fit in the reflector opening.

yes, it will fit
xpg, 219b, and LH351d are all built onto the same 3535 standard size footprint:

I calculate the 3500k LH351d will be only 4% less bright than the stock cool white XPG. This is not a visible difference.

you might also want to try a 5000k LH351d. It should be 27% brighter than the XPG, though that is only a barely visible difference. Try both Smile

in the next photo, on the left is your Nitecore.. note the entire footprint of the LED is visible in the reflector opening.. it will be the same for the LH351d (larger dome, but not larger footprint)

on the right, I pasted the LH351d image onto the Nitecore reflector so you can visualize the difference:

it is not expensive to find out
here is a source for a 3500k LH351d

note you can buy the LED already installed on an mcpcb, and you can test fit the reflector over the new LED before removing the original LED..

I hope you measure the change in output before and after, in your actual light, and post your results…

good luck with the mod

Thank you so much for the help! I do realize that small percentages aren’t noticeable.

I’ll probably try both the 3500k and 5000k LH351D then. But I need to figure out how to disassemble the head on this light to be able to get to the emitter first. If this is successful I might consider replacing the emitter on my EC25 cobra as well, I hate the stock XML on it.

The CRI on the 3500k LH351D you listed is only 80 compared to the 5000k which is 90. I have seen 3500k with CRI 90 before.

Sadly I don’t have any way to measure the output. It would certainly be nice if I could.

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> The CRI on the 3500k LH351D you listed is only 80 compared to the 5000k which is 90. I have seen 3500k with CRI 90 before.

my mistake, yes, seek a 90 CRI option..

> I don’t have any way to measure the output.

its not critical, I think you will enjoy the LED swap regardless

if you care to learn to measure output
there is an android app called ceiling bounce.. I have not tried it

I use a light meter…
we dont need to measure exact lumens so much as to get percent change..

as far as how to open your light..
I dont have a lot of experience, and sometimes I break things, so, wait for more qualified help.. lol

basically though something unscrews from something, and then there are a couple of wires to unsolder.. not rocket science, but it helps to be able to see small things, or wear magnifyers.. and you will need a few supplies in a tube, like solder paste and thermal paste..

here is a light I modded the LED on, the pics might help give you some idea of the process.. and I think your MT2C might be assembled in a similar way
https://budgetlightforum.com/comment/1677530#comment-1677530

here is another light I changed the LED on..
the main challenges was defeating the red loctite holding the head on:
https://budgetlightforum.com/comment/1642778#comment-1642778

swapping LEDs is not complicated (getting the light open can be the biggest hurdle).. you can do it,
and there are lots of people here that will cheer you on Smile