Emitter swap and output differences using same stock driver?

[300Z]

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?

 

[pc_light]

I've done the same emitter only swap from an XP-G R5 to a higher CRI emitters a couple of times. The move will be pretty much a lateral in output and runtimes, with differences ~+0-20% and being barely perceptible.

Generally in similar situation where the max current is less than say 2 Amp, I've resorted to the 219C (D240) or even 219B for their improved tint and CRI. Reserving the use of SST20 or LH351's to where the max currents might run higher.

With swaps from the much older XR-E or Lux III's to the said emitters the jump was 100%.

The Nichia 219C will give a comparable beam pattern to the XP-G, the SST20 would be slightly tighter and the LH351 slightly wider (w/defined edges around hotspot).

 

[300Z]

Thank you!
I'm hoping that with a newer emitter improved efficiency I wouldn't lose much output despite the lower output of the warmer tint.
I still see a lot of people recommending the 219B, but it's a much older emitter and thus less efficient compared to the 219C and they talk about the "rosier" tint but personally I don't like it, it doesn't seem as natural as the 219C from my Jaxman E3.
I really would like to use something around 3500k this time but I think I might have to settle for the 219C 4000k because I don't know if the LH351D would fit in the stock reflector opening, judging from pictures it looks bigger than the SST20 and 219C.

 

[pc_light]

Based on the few such similar swaps I've done, my expectation of higher CRI with similar (or increased) output were met.

Good binned 219C are nice, very much also a favorite. I have the Jaxman E3 with 219C in 5700K and it really is a pure daytime (yet not cool) white, very nice.

Interesting that you mentioned 3500K temperatures, I swapped my first 3500K hi-CRI the other day (a hi-CRI 219B). The resulting output, high-powered-incan-like with no tint shift in low, exceeded my expectations. My experience with the output of SST20 at 3000K was one-hit (in an aspheric) and one miss (in a TIR). Unlike my experience with a warm LH351D (2700K in TIR) which I disliked and swapped again with a 219B.

Your size concerns about the LH351D are well founded. While the emitter mount footprint is the same 3535 size, there's something about the LH351D dome. Whether it's the additional dome width, height or both the beam hotspot is definitely larger with a more distinct edge compared to XP's and Nichias. Fortunately dedoming the LH351D can help, provided the subsequent loss in output is acceptable.

GLWS(swap).

 

[bykfixer]

So does de-doming an emitter reduce it's total output? I always thought it just caused the out the front angle to differ.

 

[pc_light]

So does de-doming an emitter reduce it's total output? I always thought it just caused the out the front angle to differ.

I've never measured for myself but on the basis of measurement by others, there seems to be a slight reduction from de-doming (we're talking like 10% kinda numbers, so perhaps the equivalent of a lower BIN rating); setting aside any additional loss from slicing away any of the phosphorous (as is sometimes done for the Cree X#.2 family of emitters to eliminate green tint-shift).

Dedoming also typically lowers the resulting color temperature, which has the perceived effect by the eye as "less bright." The dome's slight contribution to the output and higher color temperature might have something to do with capturing and "recycling" light back on to the emitter surface.

While dedoming does reduce the front angle of the hotspot center so that one can see farther away, reducing the size of the hotspot overall reduces the area being illuminated at any given distance.

In the past I've dedomed to effect color temperature or to help fit optics, and on occasion by accident For some lights (e.g., Cat6 V2) I've even swapped out the HI emitter (XHP35 Hi 5000K, <70CRI) for a HD one (XHP35.2 HD 4000K, 80CRI) in hopes trading distance for better color temperature CRI and output.