Night vision is defined as the ability to see in low-light conditions. This idea is often confused with thermal vision which is completely different and does not require any light at all. All night vision equipment requires a source of illumination.
Fun Fact: Some night vision devices have large flashlights known as IR illuminators. This wavelength is invisible to the human eye but can be detected by the night vision camera.
There are several phone apps offered by both Apple and Google that claim to be able to offer “night vision”. The question we want to answer is how this night vision is achieved. It’s possible that these apps are simply altering the characteristics of the image (like brightness and contrast) to make them more low-light friendly. Unfortunately, this would mean that no residual light amplification took place thereby disqualifying it from the definition of night vision.
After conducting some thorough testing and reviewing the developer notes, it seems to us that these apps do in fact offer night vision functionality that goes beyond just basic image manipulation. One channel used to achieve this is increased exposure times via the camera’s sensor. This manipulates the camera at a hardware level to allow the sensor to capture more light over a longer period of time.
However, it should be noted that it’s important to use a tripod when increasing the exposure time. The increased exposure results in a laggy image of sorts and needs stability.
I went ahead and imported the original photos into image editing software and attempted to recreate it using basic image manipulation. The end result was surprisingly close to the marketing material (see picture above) but still clearly lacked a certain detail and finesse that only the app is capable of producing.
The results speak for themselves. These applications clearly use hardware level manipulation of the camera to achieve a picture that would not be possible through basic post-image manipulation alone.