That is why R9 is often mentioned separately.
R9-R12 are saturated colours and were all not part of CRI because CRI represents how natural colours look, not how saturated. They are important for good lighting though, and with leds the R9 (saturated red) is always the bottleneck so that is the one mentioned.
Okay that makes sense. I just thought it was discussed because it was always lacking…
With the Zircon 803 installed over the LH351Ds, R9 came in at 96 as you can see in the data above. That’s what I found most impressive since the LH351D typically comes in around R9 60-70.
I’ll retake measurements without the filter when I get a chance.
thanks for clarifying, I was confusing SST with LH351d
that IS a big jump in expected R9 for an LH351d,
great visuals, love your color graphs
| CCT | Duv | CRI | R9 | ||
| C8+ 351D 4000K | Without filter | 4200K | 0.0039 | 91 | 70 |
| C8+ 351D 4000K | With filter | 4060K | –0.0019 | 97 | 94 |
| D80v2 351D 4000K | Sliced | 3800K | 0.0012 | 93 | 77 |
Edit: added D80v2 with sliced LH351D
outstanding results, never expected R9 to go up by 34% from using an 80% transmissive pink filter. (minus green)
great info… you are the first to ever make me aware, of the strong positive effect of Lee Filters on R9.
thank you!
I generally see +10~20 pts of Ra with 803, 5~10 with 804.
This LH351D 4000k with +24pts is indeed significant but don’t expect it to always be that high.
Of course, it’s not really increasing the output of R9. Rather the filter is just reducing the output of all the other colors so they match the R9. Result is in a CRI test, R9 rates higher.
Filters do have some disadvantages.
Do the filters last forever (like for several years), or does their effectiveness change with time (even when not in use) or from using the light for hours at a time?
Doesn’t it also diffuse the beam some reducing the spot intensity?
Maybe i’m wrong but I always told myself that was the tradeoff I disliked the most. Narrow beam angles and reflectors generally have the most need for “adjustment” but also the biggest impact from filtering so it really is unfortunate if that is the case.
that makes sense…
apparently the CRI test does not show that reduction, it seems to rescale all the bars higher, not lower
that does not mean the comment is wrong, to me it means the CRI test is faulty. Because the test makes the filter look good on paper, but not in my reality.
from my personal experience with Lee minus green filters, they make the illuminated area Look like there is a Pink wash over everything … I really dont care for them, at all. They are, to me, just a cheap plastic toy to play with… I do not take them seriously, and would not want one on a light I consider valuable or special…
and yes, the lumen penalty is another reason I lose interest in filters…
They degrade over time.
Regular Lee filters degrade very fast. A few months at most in a high output light.
Lee Zircon filters are specially designed for LED use. They last much longer. They’ll still degrade, but I suspect it might be a few years before it is really noticeable.
Fortunately, the filters come in sheets. One sheet gives enough material for many filters.
The “pink wash” you mention is probably just the filter lowering the color temperature lowering to something below what you prefer.
If you prefer 4500K, you probably won’t be happy putting a filter on your 4500K LED. The filter might lower the color temperature below 4000K. Try starting with an LED with a cooler color temperature than you normally use. Then when you apply the filter, hopefully it will lower the color temperature to your preferred level.
Also, if things look TOO pink, the issue might be the filter lowered the output too far below the Black Body Line. In that case, perhaps the minus green filter you’re using is too strong. Try a weaker filter that does not remove as much green.
My main EDC is an FW1A that I installed an LH351D @ 4000k into as soon as I bought it. I would love to try this out for grins, how small a chunk can the Zircon filters be purchase in and do you just cut them with scissors?
Thanks Matt
this swatch book has a 1x3” piece of over 200 samples… among them are about 5 levels of minus green
they are not the high temperature Zircon version… I think Boaz is better for that
imo, you would do better by slicing the domes, than putting pink plastic (lee filters) under the lens… yes, its thin plastic, and cuts easily… I use the lens as a template and cut around with an exacto… I cant cut a round circle with scissors at all.
Jon, I am not unhappy with the color temperature… but the led does not seem to have the pop I expected. It just does not seem to live up to the CRI numbers. I chose that emitter due to the fact that it is the right temperature, pretty efficient and works really well in the reflector. The SST-20 had a to tight hotspot along with an XP-L Hi and the HD just does do anything for me. I have never tried to change the tint in this manner. I do use them from time to time with digital IR photography, but that is a different beast.
I also find the LH351d a bit “washed out”.
I blame two factors that are different than the SW45k
The LH351d has less R9 CRI (specifically the Red output). The SST and sw45k are 90+ R9 CRI… the LH351d is lucky to hit 70…
the second factor is that LH351d, and also SST-20, have positive DUV, iow, Tint above the BBL, in the yellow/green range, instead of the sw45k which has tint below BBL
by slicing the LH351d, you move the Tint below the BBL… it does also lower the CCT 500 points
anyway, I hope you find a combination that suits you.
I agree btw that both the SST and 219b have smaller hotspots than the LH351d…
the supposed extra efficiency of the LH351d is spread over a larger target, so though more total lumens, is not necessarily more Lux on target
the LH351d tried to lay a claim to the sw45k throne, and imo, the coup failed miserably
even after cutting the dome off the LED… LOL
I quite like sliced LH351D. Specifically the “dog farts” bin at 5000K.
Output feels a lot like XPL HI, but with better CRI.