Fifth, there are some options on the wavelength. ams OSRAM offers different wavelength options for the application. Indeed, the most common option for most applications is 850 nm because it is barely visible by humans and still offers a high signal on the detecting side. Nevertheless, when looking directly into the light source, a faint red glow can still be perceived. For applications in which this could be disturbing or not desirable, a longer wavelength of 940 nm is used. These are practically invisible to humans (100 times less than 850). It is still visible by cameras, but the signal is reduced by 60% as compared to 850 nm. The 810 nm is still a special color that was created for iris recognition. It is more visible for humans and for cameras than 850 nm and it has shown some benefits in automated car plate recognition, for instance. Nevertheless, before actually using it the customer must check that the optical system does not significantly block light at 810 nm. The largest LED choice is at 850 nm.