940nm LED or 850nm LED?

There have lots of application for IR LED.

850nm infrared LED, 940nm infrared LED ect are all IR LED. This wavelength can be package with different package like SMD LED IR LED, through-hole LED IR LED ect.

Then how we choose the IR LED for our application in our design?

This is depends greatly on the specific situation. For example, 940nm is considered "fully covert" as teh illuminator's output is nearly invisible to the human eyes and 850nm is considered "semi-covert" and has an output that produce a soft dim red glow at the illuminator's front cover. The light produced by our white light illuminators is fully visible and has a color temperature of 6500K(it's kind of cool white led temperature).

The benefit of using the 850nm or 940nm wavelengths is that they do not produce "light pollution", whichi is desirable in some circumstances and dictated bu law in others.

The beefit of white LED(white SMD LED or white throguh-hole LED) is white LED will offer a strong deterrent against crime. In order to use the 940nm or 850nm models, the security cameras being used must be "true day and night" cameras. These cameras are equipped with an IR cut filter that is mechanically removed in low light conditions. Cameras with a non mocable IR cut filter will block the light produced by the 940nm and 850nm models. When choosing between a 940nm and 850nm wavelength. It is important to know that most cameras are less sensitice to the 940nm wavelength. This is why the illumination distance specifications are shorter for these models. For this reason, 940nm is typically used only when then illuminator must be "fully covert".

Is it that can solve your problem? If you need more information to make a decision just feel free to let contact us!