[Reference] Nichia E17A/E21A (2000K - 6500K, R9050/R9080, color) CCT and tint shots

Is there some specific tint mixing combinations you would like to see?

I’m going to test at least
2000K+6500K
3000K+4000K
3000K+4500K
4000K+5000K
4000K+5700K

Here are the possible combinations

Just as a wild curiosity, it could be fun to see what the RGBA mixed results in.

3500K+4500K certainly would be helpful (to replace the D240)

4000K+4500K as a neutral tinted (?) 4250K

3*4000K+1*5000K if possible

2000k + 3000k. Ive been using this nightly. Curious what it measures. Thanks.

Not much reason to mix such close color temperatures. The difference between 4000K and 4000+4500K will be practically indistinguishable.

Tested the difference. CIEDE2000 color difference is 1.44 which means there’s no practical difference. DeltaE >3 starts to be obvious.

Woohoo, finally Maukka chime in. I’m still on the road to Malang city when I get the notification to this thread. Drove 400km and still 60km to go… Man…LPS everywhere in Java island

[Clemence]

Aren’t they just glorious (sorry, chart doesn’t reach warm enough to show 2000K, 2200K, 2000+3000K).

CRI data for all the emitters and some tint mixes. All except one mistake at 700mA per emitter.

2000K
2200K
2700K
3000K
3500K
4000K
4500K
5000K
5700K
6500K

2000+3000K
3000+4000K
3000+4500K
3500+4500K
4000+4500K (350mA per emitter, oops)
4000+5000K
4000+5700K
2000+6500K

Thanks a lot maukka and clemence.

This is really cool, and I should definitely try some E21A emitters.

Any idea how a 2700K+6500K or 3000K+6500K combo would look? Ideally I’d hope to hit near 4200K with duv –0.008 or so.

Edit: On second thought, perhaps I should just go for the 4500K emitters by themselves. They seem just about right, aside from being a bit less rosy than desired. With the flat surface, it’d probably have a fantastic beam.

Here’s data in a big table:
https://docs.google.com/spreadsheets/d/1CERSuF2JvYtjsoyPh-wEZ0dG6fSI-FDCjcTEVMSppiw/edit?usp=sharing

I haven’t measured lumens yet, so the Y column is just relative brightness.

Open the chart in a photo editing program and draw a line between the emitters you’d like to mix and eyeball the xy coordinates at the middle point. Enter them to a calculator such as this one: Calculate Duv from CIE 1931 xy coordinates | Waveform Lighting

edit: as it happens, in my image the duv (with a bit of a multiplier) is pretty much the 1:1 pixel distance from the BBL, so that helps too

maukka, could you hold total current fixed but change current of components that mixing?
It is interesting would it be trajectory of such kind or not.

Here’s the spectra and CIE plot for the E17A color LEDs

SRGB color space for reference

Only the CRI for the amber LED is of interest

Amber looks like a low CRI extremely warm LED. Mixing red and amber can produce something interesting…I request a test for this Maukka.
Red on the other hand is very close to Cree’s new 660nm XPE2 photo red except it has very wide spectrum coverage. A very good candidate for night vision friendly torch.

[Clemence]

Thanks Maukka for providing those extremely useful test data for us. I have a few questions.

1) Why does tint mixing drop R9 so much on the 2000k+ 6500k

2) Could the low R values for 2200k be a fluke?

3) If I remember correctly the batch of E21A you tested last year was much rosier. Is that correct? This batch seems to hug the BBL similar to the Optisolis.

Also a request if it doesnt require too much effort is if you can test 2000k+2700k, 2000k+4000k, and 2000k+4500k. Of it require much effort to setup the test then nevermind.

Thanks again for your hard work and contribution.

Let me try to answer those.
2000K has quantitatively more red than 6500K. 6500K measured with D65 standard while 2000K with incandescent baseline. Combined, the resultant R9 will result in less R9.
Early test done at 100mA current. Some LED produces less CRI at low current, and more R9. Different behaviour for different phosphor chemistries.
2000K and 2200K rated at R9050 not R9080.

[Clemence]

These two scenes are amazingly similar!

What’s that game called, Clemence?

AFAIK it starts with something “…find hidden objects…”