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 )
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?
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.
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 ?
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
cheers