850 nm vs 940 nm IR
The two common infrared light colors. 850 reaches farther with a cleaner picture but shows a faint red glow; 940 is close to invisible but reaches less far.
What it means
IR illuminators are sold mostly in two wavelengths, measured in nanometers (nm):
- 850 nm: closer to visible red. Looking straight at the illuminator, you can see a dim red glow.
- 940 nm: farther from visible light. The emitter shows little or no glow.
What it changes in the field
Night vision sensors and tubes are more sensitive at 850 nm than at 940, so the same illuminator power gives more range and a cleaner image at 850. Makers that sell both versions of the same unit list the 940 nm one with roughly 10 to 15 percent shorter detection range. Hunters report 940 nm images getting noticeably grainier at distance.
The trade is the glow. Whether coyotes and hogs notice an 850 nm glow is debated. Some hunters report pressured coyotes reacting to it, especially when the light points straight at them; others see no effect. There is no settled field study we can point to.
A common pattern: 850 nm for range and picture, and 940 nm where animals are heavily hunted and wary, accepting the shorter reach.
What to look for
- The maker’s range figures for both versions, if offered, measured the same way.
- A more powerful 940 nm illuminator can partly close the range gap.
- Tube night vision also sees 850 nm better than 940 nm.
How we use it on this site
We record the illuminator’s wavelength as the maker states it. Where a maker publishes range figures for both versions of one unit, those paired figures are the fairest way to see the trade.