BLOOD Light

[Henk4U2]

@Lightbringer

@Henk4U2

Have done some reading. You need a light source with appr. 465nm wavelength.

That would be violet(blue). Some grow lights are 465nm. NB Royal Blue is 440nm-450nm.

Violet would be about 405nm. 470nm is “sapphire blue”.

465nm would be close to the latter, so that’d be a nice purty blue.

Obviously quoted the wrong source when I wrote that 465nm is violet(blue).
But then again: I’m colorblind. Awkward.
A bit like Mendel, the founder of genetic’s and very reluctant sharing his own gene pool.

Did a bit more reading: the words Coleman light keep popping up.

[klrman]

@Lightbringer

@Henk4U2

Have done some reading. You need a light source with appr. 465nm wavelength. That would be violet(blue). Some grow lights are 465nm. NB Royal Blue is 440nm-450nm.

Violet would be about 405nm. 470nm is “sapphire blue”. 465nm would be close to the latter, so that’d be a nice purty blue.

Where would I find a 465nm blue already mounted on a 20mm copper DTP board to fit a C8 host? How bright would a 465nm be, anyone know?

[Cereal_killer]

@klrman

Where would I find a 465nm blue already mounted on a  20mm copper DTP board to fit a C8 host? How bright would a 465nm be, anyone know?

465nm is what Cree calls royal blue.

From RMM here

[klrman]

@Cereal_killer

@klrman

Where would I find a 465nm blue already mounted on a 20mm copper DTP board to fit a C8 host? How bright would a 465nm be, anyone know?

465nm is what Cree calls royal blue. “From RMM here”:http://www.mtnelectronics.com/index.php?route=product/product&path=60_78&product_id=751

Thanks for the link. They rate it as Estimated Output @ 350mA: 575mW. I'm no expert, but what is that about....50 lumens?

[Cereal_killer]

Probably a good guess, maybe a little higher on DTP with a good lens. The lowest current I run one at is 700mAh and it’s behind the wide ledil CUTE pebble finish that Dale estimates to cause a ~33% optical loss and it measures 97lm in my light box.

Do keep in mind it will actually be much more power output than 97lm of white light, it can give you a headache pretty quickly. The cheap meters probably read narrow band color light lower than reality as well.

[Cereal_killer]

Might I suggest the royal blue XT-E. Same target wavelength as the XP-E2 but they’re designed to be extremely true to their binning. Binned into 2.5nm groups (so you can be sure that 465nm led you purchase will be almost exactly 465nm). Max drive current is spec’d at 1.5A (vs 1.0A spec for the XP-E2)!

Also the XT-E will throw better if you’re not planning to dedomed the XP-E2 (the XT-E can’t be dedomed and if you did dedome the XP-E2 it would then beat the XT-E in throw).

[Barkuti]

https://www.arrow.com/en/products/search?q=xteary&filters=In+Stock:Yes;

Closest to 465nm one seems to be the N08.

[Jerommel]

So, how is blue gonna help spot blood?

[Jerommel]

@Cereal_killer

@klrman

Where would I find a 465nm blue already mounted on a  20mm copper DTP board to fit a C8 host? How bright would a 465nm be, anyone know?

465nm is what Cree calls royal blue.

From RMM here

Strange.
470nm is “blue” and 450nm is “royal blue” usually.

[klrman]

@Cereal_killer

Might I suggest the royal blue XT-E. Same target wavelength as the XP-E2 but they’re designed to be extremely true to their binning. Binned into 2.5nm groups (so you can be sure that 465nm led you purchase will be almost exactly 465nm). Max drive current is spec’d at 1.5A (vs 1.0A spec for the XP-E2)! Also the XT-E will throw better if you’re not planning to dedomed the XP-E2 (the XT-E can’t be dedomed and if you did dedome the XP-E2 it would then beat the XT-E in throw).

Good info, thanks. Don't want to dedome, so maybe I'll go with an XT-E.

[klrman]

@Barkuti

https://www.arrow.com/en/products/search?q=xteary&filters=In+Stock:Yes;

Closest to 465nm one seems to be the N08.

Thanks! They are offering right now free shipping to Canada with no order minimum. If I get the N08, then I'll have to get a star and then try and figure out how to mount the led on the star. Never did that before yet.

[Barkuti]

Dominant wavelenght range is 457.5 - 462.5nm for the 08 kit code. Quite good emissivity at 465nm thus it should provide. Closest kit code is 06 (460 - 465nm DWL range), but found nothing.

If you have never reflowed surface mount components it may be a good idea to ask for help if you have some expert at hand, or learn by yourself. Buy some extra spare blue emitters and maybe a bunch of cheapies to try and burn. Cheap copper MCPCBs here if interested.

Careful lay out of the solder paste, emitter placement, press down and paste excess toothpick removal, slow temperature ramp up and down, tight control of the temperature window, etc. There are some reflow diy videos out there, practice and calmness are good allies.

These XT-Es are not the cheapest, look for example at XP-G3 royal blue emitters for comparison. Highest flux bin Opulent Americas starboard mounted emitters available, by the way. No idea if those are DTP stars. That option may still work nice enough.

Cheers

P.S.: Aaah! Didn't noticed it was you klrman, thanks a lot again. :-)

[klrman]

Cheers Barkuti, you're welcome

Ok, I have to give it a go and get some cheap emitters and learn how to reflow. Thanks for all the above info, very helpful

[Henk4U2]

@Jerommel

@Cereal_killer

@klrman

Where would I find a 465nm blue already mounted on a  20mm copper DTP board to fit a C8 host? How bright would a 465nm be, anyone know?

465nm is what Cree calls royal blue.

From RMM here

Strange.
470nm is “blue” and 450nm is “royal blue” usually.

I read the same in the litterature but hé, I’m red-green colorblind.
Or as the waiter Manuel in ‘Fawlty Towers’ always says: “I’m from Barcelona, I know nothing. Noo-thing”.
But here is a picture that says you are correct:

As for bloodtracking, these are the two most prevalent opinions

- take a flashlight with a green led and a red led, throw in a special filter and ALL red objects stick out like a sore on a baby b* while the rest gets a brown blurr.

• take a flashlight with a blue led, and the blood becomes a black spot while the rest basks in the blue light. Because the absorption spectrum of bloodplasm matches the emission spectrum of the blue led.

[Jerommel]

Hmm… One would suspect Cyan (480 - 490 nm) to be better, because it’s the opposite of red on the ‘colour wheel’.
Another thing, isn’t blood plasma the blood without the red blood cells?

But finally: Don’t mention the war!

[Henk4U2]

@Jerommel

Hmm… One would suspect Cyan (480 - 490 nm) to be better, because it’s the opposite of red on the ‘colour wheel’.
Another thing, isn’t blood plasma the blood without the red blood cells?

But finally: Don’t mention the war!

Here you have the LINK.

And last but not least: You started it! :smiling_imp:

[vestureofblood]

I made a video testing all of the different options here if you guys are interested. TEST of Blood Tracking Flashlights!

[pc_light]

FWIW, I have an old Nitecore CU6, which in addition to the main white LED has UV (3W-365), and 5mm Blue, Red and Green LED’s. For this discussion I tested it out on some blood.

I should mention that the original white XP-G2 has been reflowed with a 4000K LH351D, for warmer high-CRI output.

Similar to VestureOfBlood’s results I found that -
(1) no single color made the blood jump out,
(2) high-CRI white was relatively the most effective,
(3) red made the blood disappear and under green the blood was the most contrasty almost black. (Unfortunately, the CU6 doesn’t have the ability to operate green and red simultaneously), and
(4) UV without Luminol didn’t do anything.

[KevinZA1988]

Best Blood Trailing Flashlight Test

Don’t waste your time and money… Watch this video.

[KevinZA1988]

@pc_light

FWIW, I have an old Nitecore CU6, which in addition to the main white LED has UV (3W-365), and 5mm Blue, Red and Green LED’s. For this discussion I tested it out on some blood.

I should mention that the original white XP-G2 has been reflowed with a 4000K LH351D, for warmer high-CRI output.

Similar to VestureOfBlood’s results I found that -
(1) no single color made the blood jump out,
(2) high-CRI white was relatively the most effective,
(3) red made the blood disappear and under green the blood was the most contrasty almost black. (Unfortunately, the CU6 doesn’t have the ability to operate green and red simultaneously), and
(4) UV without Luminol didn’t do anything.

Your test results are pretty much in line with Matt’s from Adventure Sports Flashlights.