E21A Color Test with surprising result

42 posts / 0 new
Last post
WTF
Offline
Last seen: 8 months 1 week ago
Joined: 03/05/2017 - 20:13
Posts: 318
staticx57 wrote:
Depends, what cell are you using? Quad E21A behind a 10440 would be fine. Behind a high drain 18650 with springs and all bypassed might not.

Haven’t built the light yet. Thinking about converting an old srk style light into a mule using the existing led board.

SKV89
Offline
Last seen: 1 day 21 hours ago
Joined: 12/10/2017 - 12:46
Posts: 4335
Location: US

With and without optic or reflector makes a very big difference in both CCT and tint. Here are two examples with the SST-20 4000K. Bare emitter is always much cooler.

http://budgetlightforum.com/comment/1541829#comment-1541829

http://budgetlightforum.com/comment/1546918#comment-1546918

djozz
djozz's picture
Online
Last seen: 8 min 17 sec ago
Joined: 09/07/2012 - 17:04
Posts: 17967
Location: Amsterdam

There are just so many variables.

Like the current, and the angle at which you measure the bare led. A diffuser like dcfix will average it somewhat but will still only catch and diffuse less than half of the light. Moreover, a any diffusor causes loss of blue light and warms the tint because of blue scattering more than the other wavelengths. Using optics selects other parts of the light again.

The only way to measure average tint is with an integrating sphere coupled to a spectrometer. It integrates the full 180 degrees of output and the sphere can be characterised by measuring the colour-specific light loss over the spectrum and correct for that. Maukka is the only amateur I know of to have that setup and post results with it.

Joshk
Joshk's picture
Offline
Last seen: 1 week 4 days ago
Joined: 09/09/2015 - 12:12
Posts: 2719
Location: USA

Update, I got a reflector in the mail yesterday for another project that happens to fit the E21 perfect. The results are much improved.

CIE

Ryzbor
Ryzbor's picture
Offline
Last seen: 2 days 22 hours ago
Joined: 01/21/2018 - 10:52
Posts: 385
Location: Poland

Did this particular TIR lens, it seems a narrow one, result in a cross pattern in the beam?

virence.com Nichia E21A sw30+sw40 Wizard Pro ; Skilhunt H03 XP-E2 660nm ; Wizard Pro E21A 2000K ; S2+ E21A sw40 d220 ; Sofrin C01R 660nm, Mf01 Mini Nichia 219B sw35+sw40

Joshk
Joshk's picture
Offline
Last seen: 1 week 4 days ago
Joined: 09/09/2015 - 12:12
Posts: 2719
Location: USA

No it looked like a normal beam with a round hotspot.

Ryzbor
Ryzbor's picture
Offline
Last seen: 2 days 22 hours ago
Joined: 01/21/2018 - 10:52
Posts: 385
Location: Poland

Interesting. Which particular TIR did you use?

virence.com Nichia E21A sw30+sw40 Wizard Pro ; Skilhunt H03 XP-E2 660nm ; Wizard Pro E21A 2000K ; S2+ E21A sw40 d220 ; Sofrin C01R 660nm, Mf01 Mini Nichia 219B sw35+sw40

Joshk
Joshk's picture
Offline
Last seen: 1 week 4 days ago
Joined: 09/09/2015 - 12:12
Posts: 2719
Location: USA

I’m not sure I can reveal my source. It’s a trade secret Silly

Joshk
Joshk's picture
Offline
Last seen: 1 week 4 days ago
Joined: 09/09/2015 - 12:12
Posts: 2719
Location: USA

I bought the cheapest one on AliExpress for $0.75.
https://www.aliexpress.com/item/32817065402.html?spm=a2g0s.9042311.0.0.6...

Joshk
Joshk's picture
Offline
Last seen: 1 week 4 days ago
Joined: 09/09/2015 - 12:12
Posts: 2719
Location: USA

I gave the DC fix a try today. Too close, and it doesn’t diffuse well. Too far and it doesn’t catch the warm light. It needs a reflector. I made a 13mm high reflector for it, but the light from the E21 is so concentrated it was still too close. Drr. I’m not sure if I will continue the project, since the E21 hates 2amps anyway.

Joshk
Joshk's picture
Offline
Last seen: 1 week 4 days ago
Joined: 09/09/2015 - 12:12
Posts: 2719
Location: USA

I tested with all different powers on this new thread:
http://budgetlightforum.com/node/69149

Pages