I’ve investigated it a little bit more with spare XHP50.2 on mcpcb (ordered 2, to be safe). It produces pleasant white light in quite wide angle, but sides have very strong green-yellow tint. Without reflector, it’s ok, but when reflector is used, this side light is reflected forward and causes this awful color. So this is “normal” for all XHP50.2 (can’t imagine, anyone would buy that and be ok with it) or are both my emitters lemons?
I really hate this, it’s worse than how it looks on that photo. What are my options? Swapping it again for XHP50 (not .2) 4000 K?
The led manufacturers make their leds for the lighting market, not for flashlights, apparently in general lighting fixtures (that generally produce flood light) this strong tint shift does not happen.
In your case going back to XHP50 could be a good idea. The 4000K 80CRI leds from Cree usually have a nice tint so that may be still an option? (no idea where to buy one though)
with the “flip chip” technology a slice of the emitter is pretty easy as there are NO bond wires to worry about. You could try slicing with a good sharp razor blade , staying just above the phosphor layer. Then you cut straight down beside the main die and take off the outer layer of the phosphor to clean up the olive tint around the edges of the center of the beam.
Here is an example of the 70.2 in a ThruNite TC20 with a cool white 70.2 in it , but usually the end result is very similar with the 50.2 or the 70.2.
Before Slicing…
Not the greatest slice I ever done but here is the basic idea in the end…
Like robo819 shows above, dicing the phosphor off the substrate goes a long way towards eliminating the unwanted tint shift on the flip chip emitters.
When the dome is on it’s somewhat difficult to see where the die actually is, but once the dome is sliced off it’s much easier to see the actual die and make the vertical push cut down to the substrate, a flick outward then usually dispenses of the phosphor that is layered onto the substrate. I don’t do this so much for gaining throw as to rid the beam profile of the ugly tint shift in the aura. This is what I refer to as a slice and dice.
Built these 2 drivers (all 0603 components and legs bent in on tiny85’s)
Stacked them together, wired the Nitecore stock drivers switches and switch LED to them with 32AWG wire (first pic is first driver of stack up going in and being wired then second driver set down on top and wired)
Dual drivers tested and running, just waiting on mcpcb glue to dry to assemble it!
Edit teaser pic for now, video of running tint mixer light coming later once it’s dark out.
Your pics load slow, I think because you insert them full-res. You set them to display a screen percentage so it displays good, but the page still loads the full file sizes.
I use flickr and although it is a pain to extract the links for use in inline images, they do offer links for a variety of smaller sizes of your uploaded picture.
Thumbnail Suffix Thumbnail Name Thumbnail Size Keeps Image Proportions
s Small Square 90x90 No
b Big Square 160x160 No
t Small Thumbnail 160x160 Yes
m Medium Thumbnail 320x320 Yes
l Large Thumbnail 640x640 Yes
h Huge Thumbnail 1024x1024 Yes
Also I found ‘r’ makes 1456 x _, also keeping proportion. So even bigger than the “huge thumbnail”
And I found another, ‘g’ does 728x_ with proportion.
b: