TEST of Blood Tracking Flashlights!

[xxo]

@TBone

Hemoglobin has a high absorption rate around 415 nm. That is why UV light is used in forensic science to check if a stain is blood (very dark) or not (somehow reflecting).

But this is totally useless for hunting. You cannot chase something that is not reflecting. Most of the plants and most grounds do not reflect UV so you will see nothing.

I have watched several videos about blood tracer flashlights but I am still not sure how good they work. Most video material is just too bad.
Looking at the reflectance (what you see) of blood (example figure) there are not a lot of wavelengths that blood is reflecting: Red, deep red and infrared.

Any light with a warm spectrum would be much better that a cold LED light. The warmer the better. Maybe assisted with some extra red and IR LEDs.
Using orange or red filters may be even better. They cut out all colors below 600 nm. Seeing less green should help in the forest.

LED blood tracker lights work fine - reds/oranges really pop out, but since these use both red and blue LEDs running together, blues also pop out (not normally a problem when hunting as blue is rarely encountered).

An incandescent light with a blue filter doesn’t pop red/orange colors as much but it does not pop blues and better isolates red/orange from other colors. Red and orange filters do not work at all.