About the 219B: not entirely sure, but my guess would be something about the design of the die-phosphor interface. There is some tint shift, but less than lots of LEDs. Certain Cree LEDs with non-uniform emission surfaces (1st gen XML, MT-G2) tend to have less tint shift because they behave almost like multi-die emitters with very small and well-separated component dies, and generally smaller dies are less tint-shifty than bigger ones because a photon emitted obliquely doesn’t have that much more phosphor to pass through compared to a photon emitted in a direction normal to the plane of the die.
Lmao no they haven’t. It depends heavily on the exact LED model. Lots of Nichias (such as 519A) have significant tint shift, and so do lots of Luxeon emitters (like V2). But certain emitters that are designed without a secondary optic in mind (such as Optisolis) may have less tint shift when used in this way.
With all due respect , the reason you would pick 219b over 519a is if you prefer the rosy tint of 219b 4500k over the yellow tint of 519b 4500k and 5000k (and green-yellow at lower output, especially 5000k). I have a few 519a lights in 4500k, 5000k, and 5700k, and none of my 519a, whether dedomed or mixed tint, reproduces that same rosy tint of 219b 4500k IME.
I do understand your point, and my question was not rhetorical; I was genuinely curious why the OP would consider emitters such as the 219C over 519A.
The OP does not state any tint preference in the original post, and is considering a long list of emitters. Thus the best I can do, given the limited information, is to point out the strengths/weaknesses of the emitters listed. Tint is a matter of preference, and rosier is not objective better; thus, I cannot state neutral tint as a weakness, or rosy tint as a strength.
I have been using my new Convoy T4 5700K with a 219F and it has a lovely tint and beam pattern. Super pleasing to use for normal EDC stuff and none of the yellow or green tint I get with many 519A emitters.
I have a T4 with a 519A and it never saw much use due to its ugly beam which varied with power levels. The 219F is so much nicer to use in real life for me, I won’t be going back to the 519A.
, the reason you would pick 219b over 519a is if you prefer the rosy tint of 219b 4500k over the yellow tint of 519b 4500k and 5000k (and green-yellow at lower output, especially 5000k). I have a few 519a lights in 4500k, 5000k, and 5700k, and none of my 519a, whether dedomed or mixed tint, reproduces that same rosy tint of 219b 4500k IME.