In the Effect of Infrared in Night Vision Photography article, I showed the difference of capturing visible light, infrared light, and both types of lights at night. In this article, we will find out what is the effect of trying to amplify the signal in post-processing, such as using a night vision scope.
Taking the visible light and infrared light photograph shot in the article mentioned above, the following are the effects in software post-processing.
Auto levels (Adobe Photoshop CS2) provides more details in the photograph, and still preserves the smoothness and pleasantness of the original (see photo below).
When brightness and contrast is increased equally, much more detail become apparent (see photo below). You can now detect trees, light posts, etc. Of course, noise is now readily apparent. This image more closely resembles what you might see through a night vision scope.
The photograph is not as pleasant, but if you life is dependent on night vision, you'd opt for the details in this photograph.