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

Yeah, drgentr asked for 4500K so I tried to get close to it, I agree it’s not worth it.

For lower CCTs, here are the tints I get in a tint ramping flashlight for example :

Using 6500K-2000K would have lowered the duv even more, as shown in maukka’s test, and for a larger portion of the CCT range. (also in this flashlight the leds run at half current at the middle of the tint ramp, so the duv is not as low as it could be )

thanks for taking the time to share info

I really appreciate the picture you posted, makes it easy to see what is happening, when using a 2000k LED as the bottom CCT of the mix

even in stock form, the IF25 with built in tint mixing that uses a 2700k as the bottom CCT, looks very interesting. But I dont know the duv values

You’re welcome.

Yeah 2000K really bring down the mix into the rosy region compared to 2700K thanks to that BBL curvature into the red.

I made some measurements of the stock IF25 here , of course the sst-20 6500K are pretty bad. A few posts below I put sliced LH351D in it. But the CCT range is limited compared to E21A which allows to mix very spaced CCTs

I didn’t get a reply in the Hank thread so I’m going to try asking here in case anyone knows. How much does the CCT on the E21A get pushed up when it’s run at 1.2A versus the 0.7A in your tests? Like say 5000K would be more like 5500K and 4500K becomes more like 5000K?

There is a spreadsheet with all the measurements : https://docs.google.com/spreadsheets/d/1CERSuF2JvYtjsoyPh-wEZ0dG6fSI-FDCjcTEVMSppiw/edit?usp=sharing

Thanks I didn’t know about that. CCT in those tests are fairly steady but how is it measured?

In Maukka’s review of the KR4 here: Review: Noctigon KR4 (18650, 4xE21A 5000K, CRI96) the 5000K model shifted quite a bit from lowest power to highest power setting.

I don’t know what to make of it.

The MCPCB in the KR4 is not nearly as good as the Virence ones, thus the LEDs heat more and there is more tint shift.

https://www.andwinmcpcb.com/sinkpad-pcb/ :wink:

These are DTP MCPCBs, E21A/E17A don’t have a thermal pad so you can’t use those (unless you have a grounded cathode driver and DTP the cathode but that’s a special case and even then only one side will have good thermals). They have a poor thermal conductivity dielectric layer and will perform badly. Virence’s MCPCBs have a very thin (relatively) high conductivity dielectric layer.

Edit : new ones even have 3oz copper pours ! https://www.eurekatronix.com/product-page/er10s1-21

I’m pretty sure they can make same or better MCPCB.

Yes they can do similar non DTP MCPCBs, up to 8W/m.K dielectric (they don’t detail the thickness) and apparently up to 3oz copper pours. Must be very expensive though.

Does anybody have a copy of Maukka’s table with all the measurements ? it’s not accessible anymore, I’m pretty sure I had it saved for offline use and yet I can’t find it in my Gdrive : This one

He hasn’t been connected for 10 months, I hope he’s well and just has other interests. Has anybody got in contact with him since then ?

is this the info you are looking for?

No I’m talking about the Google spreadsheet which has more data.

agree the spreadsheet is gone
this post has all the individual data though

maybe that can help you find the data youre looking for. (what data are you seeking?)

Damn. I thought I had a copy of it but can’t find it. A ‘take-out’ version might be on my other encrypted drive partition that I seem to have forgotten the password too :person_facepalming:

we build grow lightstrips with the Opti 5k and 2k to get 99+ CRI, im guessing we could shorten up the duv with more 2k
Parameter Value
CCT 4615 K
Duv –0.0016
CRI (Ra)(R1~R8) 99
CRI (Re) (R1-R15) 98
CQS 99
TLCI (Qa) 98
GAI 89
TM-30-15 Rf 98
TM-30-15 Rg 100
We are more interested in replicating sunlight than delta’s but an interesting discussion

How do you replicate sunlight with the opti? Don’t you need UV range in order for plants to grow?

Did you ever happen to find a copy of that spreadsheet?

This might be what you’re looking for

It was asking me to give someone permission and I think I fixed that issue.