Ive done a bit of math on the lumen outputs of the Lumintop Tool w 4000k N219b 90 CRI, 6000k XP-G2 70 CRI, 4000k N219c 90 CRI
The high modes are 80 lumens, 110 lumens, and 110 Lumens.
for me the Color Temperature and Tint of the 80 Lumen N219b is prefered. The CW makes reds look brown, the N219c has much lower R9 and a much greener Tint than the 219b. Supposedly the 219c is the same CRI as the 219b, which is true, but, thats only half the story, the R9 on the N219b is about 300% that of the 219c.
Comparing the 110 lumen 219c to the 80 lumen 219b shows the 219c is 38% brighter than the 219b, otoh, yet both have a CRI Ra of 90. But, thats before considering the RED (R9) output increase of 300% in the 219b over the 219c
now lets compare some colors on a specific light I recently had modified, on the left before, on the right after the LED swap to Nichia
(note the pics are to show color and tint, I did not take them at the same time, so the brightnesses are not accurate, the yellow light has almost double the lumens output on my meter, than the purple white light on the right.) and remember it takes a 4x incease in brightness to make a slightly noticeable difference in brightness. Doubling the brightness does not make a light Look twice as bright… anyway, I think this pic sort of demonstrates what I think might be a reasonable difference in brightness. more research required for further accuracy.
If you had to give up 48% of the lumens to gain 36% higher CRI Ra, would you do it?
Another factor is a type of CRI called the Saturated Red (aka R9 CRI). On the Nichia it is over 95 Ra, on the XPL is is a negative number, about –15. That means that the Nichia has over 500% more Red output than the NW XPL. I have never seen anyone discuss this detail, so I started a thread about it.
If Im only looking at green things, then the piss yellow light works fine. I can even tell green things apart from red things (that look brown actually).
Otoh, if there are red things to be seen, the Nichia is a Joy to behold, for me, in the way I use my lights, which is mostly at very close range and almost always below 100 lumens.
I cant wait for midnight, Im waiting to see if the drop from 0.2 lumens of XPL to 0.1 lumens of N219b is still effective to find the toilet without stepping on the cats toys, or gooey wet hairballs…
So percentage loss on a nichia swap Lumens is more than 25%, but so is the increase in CRI Ra, and so is the increase in RED CRI R9
If you had a choice to have the light on the left at 400 lumens max, or the light on the right at 200 lumens max, which would you pick?
when in doubt, the correct answer is both