Review: Noctigon KR4 (18650, 4xE21A 5000K, CRI96)

Thank you for this excellent review. :+1: :smiley:

Absolutely, otherwise it is a waste of these LED’s advantages, based on your custom sanded optic looks excellent.

Very nice review. I was waiting for the release of the E21A KR4 and your thorough review answers a lot of questions I had.

Fantastic useful and detailed review!

Awesome review as always. I finally got round to watching the TM-30 video as well so can understand the charts a bit better too.

I’m surprised there’s tint shift in the E21A with the default optic, I hadn’t heard of them having any tint shift before. I wonder if E17A with frosted optic might be a better choice overall?

Thank you for the excellent review. I was originally planning to wait to order the KR4 w/E21A LEDs, but I’m glad I caved and got one with SST-20 4000k FA3. I love the KR4, but I doubt I’ll buy the E21A version. The FA3 bin SST-20s have good enough tint to my eyes. If I’m going to downgrade output by over 50% I want a beautiful tint and beam pattern with decent efficiency. This one unfortunately has none of the above.

Hank did say he would offer multiple CCTs, wonder if 4000k or 3500k would look nicer with the stock optic? Efficiency unfortunately will be worse I’m assuming.

Your question was already answered in the review:

“I would recommend getting the floody 10623 optic as an option, which will improve the tint consistency.”

I assume you do not know that Carclo 10623 is the frosted optic.

I am familiar with the optics thanks, I was talking about E17A emitters. E17A is the smaller brother to E21A so is throwier. Under a frosted optic I was proposing that they could have similar throw to the E21A with a clear optic but still have the same benefits of the blended tint a frosted optic would give.

Are there actually ultra high CRI E17As? I know Clemence offered them for the Jet-mini but they were 80CRI max IIRC.

Yeah there are. They were available in the H04 group buy and are available on his store.

Absolutely amazing review and lovely images. Thanks for the write up and time taken to do this review.

Hank is shipping KR4s with FA3 SST-20 4000K? If so, I may have to get one.

Interesting. Did you have the aux LEDs on high mode?

It seems like it could flip between two colors if certain conditions… like if the voltage was close to a threshold, the aux LEDs were on high, and the higher of the two levels had two colors turned on instead of one. The way that could happen is:

  1. Battery measures 4.11V, so aux LEDs turn purple (R+B).
  2. Red+blue aux LEDs use more power than just blue, so voltage drops.
  3. Battery measures 4.09V, so aux LEDs change to just blue.
  4. Blue uses less power than red+blue, so voltage increases a little.
  5. Repeat from step 1.

IIRC, it checks every 8 seconds, so it could change colors about 8 times per minute. In sleep mode, it wakes up very briefly about 8 times per second to handle the blinking aux LED mode… so the animation can happen at 8 fps. Every 64 frames though (every 8 seconds), it turns on the voltage measurement circuit just long enough to get 2 samples (the first sample is junk, so it needs to read twice), and then it checks the result and decides whether to change the aux LED color. If it’s below 2.9V, it turns off the aux LEDs no matter what mode they’re in.

I don’t have a way to measure it directly, but if my math is right, the entire process should take about 1 millisecond every 8 seconds.

Awesome review Maukka!

Any idea when the E21 emitter version will be available for sale? If it’s going to be soonish, will wait and get both the K1 SBT90.2 and KR4 E21 at the same time.

Also, on the intl-outdoor site’s search bar if you type in D1S, there’s an interesting suggested autocomplete for “37D1S v2”. Sure would like to see that come out soon.

Our E21A LED package is stuck on the way for long time due to the virus issue, not sure when it will move, so, we are not sure when it can be offered. The 10623 optic will be default optic for the KR4 E21A version.

IMO pretty mediocre tint but that was to be expected for a D240 binned E21A. The D220 4500K should be much rosier.

Thanks for the review. Very useful graphs as usual! The driver looks really good.

Mine will hopefully be here tomorrow. I need to get some 18350 cells, has anyone verified the max length yet? I would like to get a protected cell to avoid over-discharging if I forget to not use turbo. Assuming turbo for the xpl version draws more than an 18350 can handle.

Hard pass. CRI99 or else :disguised_face: