Dark sport on hot-spot with D4v2 and Nichia 219b and 219c

11 posts / 0 new
Last post
aeroden
Offline
Last seen: 1 month 2 weeks ago
Joined: 09/30/2020 - 09:55
Posts: 89
Location: Melbourne, AU
Dark sport on hot-spot with D4v2 and Nichia 219b and 219c

Hi all,

I’m having a bad luck in getting a clean beam/tint on D4v2 with Nichia 219b and 219c.

Originally I was really lucky (as it turned out) with having a clean tint (no shifts) on my Drop Copper AAA with 219c@4000k.

Excited, I ordered D4v2 copper with 219c@4000k and was really disappointed with its hot-spot being yellow/greenish in the very middle. Later I got several others 219c lights (S2+, and 2x drop AAA) and they all got “dirty” hot spots too – at this stage I thought I’ve figured out why people rave about good’old 219b so much.

I then got FF-light ROT-66 G2 and E12, both with lots of 219b 4500k. Both use clear optics and produce amazing beam with absolutely clean hot-spot.

Fast-forward a year, dual-channel D4v2 came out and I developed a special love for warmer tints. So I ordered dual-channel D4v2 with 219b 2700k and 4500k – save bet in terms of tint cleanness, or so I thought.

However the light I got has similar problem – slight, but noticeable to my eyes, yellow-ish discoloration right in the center of the hot-spot. Happens both on just 2700K channel and 4500K channel (separately). It’s more pronounced on 2700K.

It’s quite hard to capture on photo, but I tried here: https://imgur.com/a/TqEskYi. Look right in the middle of the hot spot. In real life it is much more pronounced. This is for 2700k (WB on auto).

I’ve checked the emitters and it’s indeed 219*b*, no mistakes here. Colour temps look correct too.

Questions:

  • Do others have this issue with 219b or 219c emitters on D4v2?
  • Are these some sorts of specifics of D4v2 + 219* + its optics?
  • Is there a way to fix it (10623 floody lens fixes it but I loose lots of throw!)? Will 10621 narrow optics help?
  • Is it the same for D4v2 with SST20 @ 4000K or 2700K?

Continuing 219*c* 4000K experiment: my FW3A does have the same yellow-greenish hot spot as my D4v2 219c 4000K but FWAA copper does not have it for some reason – clean, pristine beam.

jon_slider
jon_slider's picture
Offline
Last seen: 3 hours 20 min ago
Joined: 09/08/2015 - 12:20
Posts: 6505
Location: Central North America

good photos

I can see what you mean, the center of the beam has less focused brightness than the perimeter of the hotspot.. when looking at the beam on a wall…

I dont think it has anything to do with the LED.. as you noted, changing the optic, eliminates the difference in beam focus in center vs perimeter of hotspot.

fwiw my Two Fwaa, regardless of which LEDs I use, also has less brightness in center, than perimeter..

I think it has to do with how the optics are focused.. not exactly the same in the middle as on the edges.. I agree there is a trade off, if we use optics that blend the beam more, it also gives less throw. There is no perfect beam, there are always compromises, depending if the light is used at close range, such as indoor distances, vs longer range, such as outdoors.

I hope you can enjoy your lights, in actual use, despite the beam not being perfect, on a wall.

Hikelite
Offline
Last seen: 6 hours 33 min ago
Joined: 07/13/2011 - 16:18
Posts: 3998
Location: Honeyland

You need to try other optics too with it, the default one is most likely not what you are looking for, especially to try the other if you don’t like the close up beam.

With the flashlights you have mentioned you do not have optic choices and you are not missing any perceived throw because there is no optic that claims the most candela.
Also you are comparing 9LED optics and 12LED optics with the dual channel D4v2 which is rather 2 LEDs offset in an optic which is kind of know to have a discrepancy that you have noticed on a wall.

Unheard
Unheard's picture
Offline
Last seen: 35 min 33 sec ago
Joined: 01/16/2019 - 11:38
Posts: 2629
Location: Germany

This kind of doughnut shows when the LED is below the focal point of the optics.

Spitzbube.

aeroden
Offline
Last seen: 1 month 2 weeks ago
Joined: 09/30/2020 - 09:55
Posts: 89
Location: Melbourne, AU

Hikelite wrote:

Also you are comparing 9LED optics and 12LED optics with the dual channel D4v2 which is rather 2 LEDs offset in an optic which is kind of know to have a discrepancy that you have noticed on a wall.

FF-light PL47G2 with 219*b*@4000k produces a perfect beam with 30 deg lens and just 4 emitters.
But my D4v2 219*c*@4000k there is a similar problem (again, with 4 emitters).

Unheard wrote:
This kind of doughnut shows when the LED is below the focal point of the optics.

I bet it worth trying then to sand off the legs of the lens to bring it a bit close to the emitter? (or does it already sit right on top of it?)
aeroden
Offline
Last seen: 1 month 2 weeks ago
Joined: 09/30/2020 - 09:55
Posts: 89
Location: Melbourne, AU

Also can anyone comment if they have similar problem with D4v2 and SST20 emitters?

Hikelite
Offline
Last seen: 6 hours 33 min ago
Joined: 07/13/2011 - 16:18
Posts: 3998
Location: Honeyland
aeroden wrote:
Hikelite wrote:
Also you are comparing 9LED optics and 12LED optics with the dual channel D4v2 which is rather 2 LEDs offset in an optic which is kind of know to have a discrepancy that you have noticed on a wall.
FF-light PL47G2 with 219*b*@4000k produces a perfect beam with 30 deg lens and just 4 emitters. But my D4v2 219*c*@4000k there is a similar problem (again, with 4 emitters).

OK, why not try another optic? What is the big loss since you don’t like what you see.

Hikelite
Offline
Last seen: 6 hours 33 min ago
Joined: 07/13/2011 - 16:18
Posts: 3998
Location: Honeyland
aeroden wrote:
Also can anyone comment if they have similar problem with D4v2 and SST20 emitters?

I do not have the 219B model but I do have a couple SST20 and they do not have that darker area, one default optic and one frosted optic, the frosted optic (10623) looks nicer for me personally as the hotspot is bigger.

Do you see that with the eyes or you take the camera and expose for the hotspot (thus underexposing the rest) and only see it in the photos?

Hikelite
Offline
Last seen: 6 hours 33 min ago
Joined: 07/13/2011 - 16:18
Posts: 3998
Location: Honeyland

aeroden wrote:
Unheard wrote:
This kind of doughnut shows when the LED is below the focal point of the optics.
I bet it worth trying then to sand off the legs of the lens to bring it a bit close to the emitter? (or does it already sit right on top of it?)

These optics have a 2 step leg, so the legs rest on the MCPCB, with a narrower diameter smaller part of the tip of the leg fitting inside the MCPCB.
You can still shave the leg if you want but they will not grip into the MCPCB anymore after that.

aeroden
Offline
Last seen: 1 month 2 weeks ago
Joined: 09/30/2020 - 09:55
Posts: 89
Location: Melbourne, AU

Hikelite wrote:
aeroden wrote:
Unheard wrote:
This kind of doughnut shows when the LED is below the focal point of the optics.
I bet it worth trying then to sand off the legs of the lens to bring it a bit close to the emitter? (or does it already sit right on top of it?)

These optics have a 2 step leg, so the legs rest on the MCPCB, with a narrower diameter smaller part of the tip of the leg fitting inside the MCPCB.
You can still shave the leg if you want but they will not grip into the MCPCB anymore after that.

I don’t want to shave the legs off fully, just some of it to bring the lens closer to the emitter. I guess I’ll order spare lens and try that Smile

Hikelite wrote:
aeroden wrote:
Also can anyone comment if they have similar problem with D4v2 and SST20 emitters?

I do not have the 219B model but I do have a couple SST20 and they do not have that darker area, one default optic and one frosted optic, the frosted optic (10623) looks nicer for me personally as the hotspot is bigger.

Do you see that with the eyes or you take the camera and expose for the hotspot (thus underexposing the rest) and only see it in the photos?

Why my eyes of course. If these dark discolorations weren’t bugging my eyes I wouldn’t bother. But I see them and hence this thread. Just trying to get non-frosted D4v2 with a clean beam.
I’ll try my luck with SST20 as well then. I also heard Hank’s SST20 @4000k come from a nice rosy bin.

Thanks for the input!

Hikelite
Offline
Last seen: 6 hours 33 min ago
Joined: 07/13/2011 - 16:18
Posts: 3998
Location: Honeyland
aeroden wrote:
Why my eyes of course. If these dark discolorations weren’t bugging my eyes I wouldn’t bother. But I see them and hence this thread.

I understand.
I have to say I do not have the dual channel SST20, but the older regular 4 LEDs SST20 single channel flashlights.