ELi5 why do Astrophotographers need to capture hundreds of pictures of the same area in the sky and lay them on top of each-other to make a clear image? Ty in advance ❤️🙏🏼
In: 1
Basically 1+1=2 but with pictures.
Laying pictures on top of pictures make dark darker, and stars brighter.
Explained more:
Night skies are really dark, sometimes stars are dim for even our eyes to see.
Couple problems with taking dark sky pictures.
1. Camera shutters need to be “open” for longer period of time to let these light in. If you do that, you start getting star trails due to the earth’s rotation, meaning stars arent pinpoint in your picture, instead shows up more blurry.
2. In order to take picture of dark sky, your camera sensor is basically more sensitive (high ISO) and creates “noise” in the picture, meaning there are dirty pixels where there shouldnt be.
Stacking multiple pictures on top of each other, gets rid of problem 1 and 2, thus creating sharp astrophotography without any unwanted noise
Latest Answers