Downrange Infrared Signatures
Since it seems to be a popular subject of discussion without much actual content out there, I’ve photographed a number of different near-infrared illuminators from downrange perspectives to attempt to compare them to each other and provide imagery that is similar to what one might experience in real life. The issue with just standing downrange and taking a photo back towards the IR source is that most digital sensors nowadays are more sensitive to higher wavelengths than the human eye, so NIR sources shine very brightly and with a bright purple hue. I've posted photos in the past comparing different devices, but they were only useful as that, comparisons between them, and not as a reference for how bright or dim they are to the unaided eye.
After obtaining an optical filter for the front of my DSLR lenses that cuts NIR energy at a similar place to the human eye (700-750nm and above has no light transmission), I've gathered devices to bring to a range and get on camera. Before diving in, I figured I'd put the call out in case anyone else has devices they'd like to see compared that I don't happen to have locally or in my personal collection. While I've got everything there, I'll probably also update this video with some through-the-tube footage to compare actual NV performance of everything on hand.
Here's the devices for the test:
Princeton Tec SWITCH MPLS - UNKNOWN OUTPUT
S&S Precision MANTA - UNKNOWN OUTPUT
CORE Survival HEL-STAR 640-09 - UNKNOWN OUTPUT
Amazon Special - 5000mW, 850nm
Streamlight TLR-VIR II - 600mW, 850nm
Surefire X300V - 120mW, 860nm
Armasight MSI8000 - 1300mW, 850nm
NiteCore CI7 - 7000mW, 940nm
Surefire Incandescent with IR Filter - UNKNOWN OUTPUT
PEQ-2a - 50mW, 820nm
DBAL-D2 - 600mW, 850nm
MAWL-C1+ - 130mW, 860nm at mid-setting
Sent in by others:
ModLite IR-850 Head - 1100mW, 850nm
Fenix TK25 - 3000mW, 850nm
Fenix TK25 - 3000mW, 850nm w/ 950nm glass filter
Sniper Hog Lights 38 LRX - 1350mW, 850nm
SHL 38 LRX - 1350mW, 940nm
Zenitco PERST-3 - 500mW, 850nm
View fullsize
An example of how they look with an unfiltered digital sensor (in broad daylight too):
(DBAL-D2, X300v, MAWL-C1+) (Streamlight VIR II, Amazon Special, X300v)
UPDATED WITH RESULTS
Here's the table of images we shot from downrange looking back into the emitters. Should be big enough to zoom in quite a ways and get a good look at each hotspot. I've got some initial thoughts but look forward to hearing what others have to say when seeing these. I'll follow up in another day or two probably with all the NVG footage of what each looks like shining out on the range and at my beautiful assistant. Special thanks to him for running all the lights and all the guys that sent in additional units to test.
Here’s the final spread of units that were photographed
We did shoot the two IR strobes at both distances but they were impossible to capture with any visible signature - removed them from the table because the photos were just black - only really visible if you're holding them in your hand and staring directly into the units. We also took the glass 950nm filter that was provided with the TK25 and put it in front of the D2 for a few shots that are at the bottom of the table. Cuts it down quite nicely and the Surefire incandescent IR filter like this looked almost identical.
Note that all displayed emitter powers and wavelengths are per the manufacturers/retailers. No additional testing was performed to verify those values. All devices had fresh CR123 batteries and those that take 18650s were used with the same Panasonic battery. Camera settings were 70mm f/4.0 0.5sec ISO1600 and images were cropped substantially and consistently for comparison table. Further distances were not feasible to photograph with very long lenses.
Click here to download large image
Update 2
The footage looking the other direction via night vision is now up. A full moon was rising to the left of the range, and had started to illuminate some of the treetops. Most of the range was in shadow though and quite dark. They were shot through an L3 unfilmed white phosphor NV device.
Here’s a very large high-res download of all the illuminators together.
