How does ‘Noise Reduction’,NR for long exposures work?
Author: admin Category: Noise Reduction
I have a Nikon D200, and it has a ‘Noise Reduction Long Exposure’ Setting on it. I know that it obviously reduces the noise from the sensor being exposed to light for a long time, but how does it work? I’ve heard something about it takes a ‘black frame’ or something like that…
It takes an exposure for the same time as the original exposure, without letting any light hit the sensor (black frame). Then it looks at the dark image, and sees where there are any bright spots or hot pixels. Then it goes into the original image and fixes the individual pixels.
It works best if the temperature is constant throughout the two exposures.
Do a search, some people have modified their cameras with Peltier chips to keep the sensor cool. The other way to do it is shooting on cold nights, much less sensor noise.
here’s a 12 minute exosure, almost no noise, 17 degrees outside:
http://cgipix.com/Portfolio_Utah_Vacation_Travel_Arches_Canyonlands.htm
August 11th, 2010
It takes an exposure for the same time as the original exposure, without letting any light hit the sensor (black frame). Then it looks at the dark image, and sees where there are any bright spots or hot pixels. Then it goes into the original image and fixes the individual pixels.
It works best if the temperature is constant throughout the two exposures.
Do a search, some people have modified their cameras with Peltier chips to keep the sensor cool. The other way to do it is shooting on cold nights, much less sensor noise.
here’s a 12 minute exosure, almost no noise, 17 degrees outside:
http://cgipix.com/Portfolio_Utah_Vacation_Travel_Arches_Canyonlands.htm
References :