BLOOD Light

I don't know anything about tracking blood trails in the wild. My wife does some forensic work, but she is looking for blood up close. She says that blood does not fluoresce. When she looks for blood on difficult to see materials (e.g. Dark and real shiny materials can make it hard to see blood). She uses 405nm and looks for the lack of fluorescence.

From what I have seen, anything for blood use is listed from 395nm up to 465nm. 465nm seems to be the most common consensus for a blood light.

I think my brother jumped on the bandwagon and has bought all kinds of “blood lights”. Honestly I haven’t seen one that worked worth anything that is on the market. There might be some secret combo but I figured if so somebody out of the dozens we have tried would have hit on it by now.

I just happen to have a UV of 395nm. It lights up scorpion like a champ. I’ll shave my chin with a straight razor and I’ll get back to you all on the blood detection part. :student:

Blood does not fluoresce under UV. It is not like urine, or semen, which do.

Period.

The stuff you see on e.g. CSI is fiction, except for spraying Luminol about, which is a quite different thing. And not at all specific to blood, many many other substances will also catalyse the activated Luminol solution to glow.

To track blood trails at night, with a torch, you either need good CRI in the red range, to actually see the blood, hopefully fresh red and frothy, (or worse, blue and cold), or a different colour balance e.g. biased to green with minimal red, to give contrast e.g. against green vegetation, where the blood looks black.

There is no miracle light that makes blood trails leap out at you.

A dog with a keen nose is invaluable.

Yeah, you’d need a tank of luminol, LCV, etc., to get blood to show up…

I’ve looked at the videos, and it seems like they’re shooting blue/cyan and maybe another color, which’d get dirt, leaves, grass, etc., to reflect light, but blood wouldn’t, to show more contrast.

“Print” a blank page on a stinkjet printer so that it puts out its requisite yellow dots on the page (to ID the printer). Yellow-on-white doesn’t show up well at all under normal (white) light.

Shine a blue light on it, so that the white will reflect blue brightly (if not even fluoresce somewhat), but the yellow dots will show up almost black.

Think it’s the same principle at work here as far as blood.

Dr Jones RGB / RGBW firmware has a mode where it lights the green & blue emitters and flashes the red emitter at about 1hz. It makes red objects jump out at you. Never tried it with blood but next time I’m leaking and have access to the light I’ll give it a try. It works very well with solid red items regardless of their reflectivity.
Maybe this would be an option with just a pair of red and blue emitters?

That is very interesting, I can see how it might work. Good old Dr. Jones.

A bit tricky to rig something up for myself, but might just try, for next deerstalking outing. Or just to practice when training the next dog, on a trail.

@Funner…. A blue light will do it.

If you don’t have a ‘blue light’, a blue Nitecore filter slipped over the business end of your favorite CW or NW light will do nicely.

Heck it’s an excuse to buy another flashlight.

Thoughts on this one, at least the drop in?

It’s 450nm http://kaidomain.com/KDLITKE-E6-w-Cree-XP-E2-Royal-Blue-450nm-280-Lumens-3V-9V-1-Mode-P60-Style-LED-Flashlight?search=Royal

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. :smiley:

Ledengine calls it “Dental Blue” I believe

I have no idea how well they work (never had a reason to track a blood trail) but Bushnell makes the TRKR (short for tracker) series of lights. I bought one when Walmart was selling them cheap, I think mine is the 250 lumen model. There is a white LED in the center and I think three red and three blue LED’s in a ring next to the benzel. Only one color can be lit at a time. I only use mine for walks at a local nature preserve that requires a red light if you carry a flashlight.

I’m looking at the Bushnell, Gerber, Rayovac, and Primos blood lights. Amazon has a add on item light for $6.52 I will try, along with one of the Walmart lights.

Amazon Rayovac blood light. Amazon.com

Solarforce has a 450nm p60 drop in.

http://kaidomain.com/S023004-Solarforce-LC-UV-Ultra-violet-450nm-LED-Drop-in

Here’s a cheap 450nm Ultrafire on Ali. Have no idea if its any good.
https://www.aliexpress.com/item/450nm-Blue-light-Outdoor-Lighting-Flashlight-Gray/32917726196.html?

xpebbl (XP-E2 blue) search @ arrow.com

XPEBBL-L1-0000-00301 is the highest flux bin, dominant wavelenght range 465 - 485 nm.

xpgdry (XP-G3 royal blue) search @ arrow.com

Looks like very recently they got a reel of highest flux bin units, right now I see 1000 units of XPGDRY-L1-0000-00601 in stock and selling 'em by the piece. (^̮^)

Cheers ^:)

That might fit a Solarforce light like the L2 series, but I seriously doubt it’s a SF module.

First, I don’t think they’d have the nerve to call a 450nm blue LED “ultraviolet”.

Second, a simple 1-mode driver isn’t rocket-surgery, so probably is just a bunch of cheap parallelled chip-resistors.

17bux for that? Feh…

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.