Recently I am really fond of night shots with starry skies and different mixes of artificial lights. I am shooting with my Sony Alpha700 and although the switch from A100 gave me a huge difference in quality I am still facing lots of problems with noise.
Recently I had seen some interesting tutorials on reduction techniques and I have decided to compare those in one post.
I have attached my A700 with DT 3.5-5.6/18-70mm lens to the tripod and shot 4 pictures with identical exposures of 20s/f5.6 ISO400 and focal length 18mm.
All originals were developed the same way giving me 4 TIFF images to work on.
1. I have just taken first one to show you the amount of noise:
Original picture
Closeup of original
2. Then I have used Neat Image software to reduce the noise of original picture, and have been using it on each picture from below methods.
Original with noise reduction
Closeup of original with noise reduction
3. Then I have used the technique presented by
Igor Sokalski on Dreamstime blogs, and derived from astro photography, where multiple images are stacked and the opacity of each picture above is lowered by 50% comparing to below image (for my four images it was 1-100%, 2-50%, 3-25%, 4-12,5%)
Opacity method
Closeup of opacity method
Opacity method with noise reduction
Closeup of Opacity method with noise reduction
4. Then I have used the method described in
Shutterbuzz by Alexey Stiop to remove people from crowded places... I found this method very similar to 'opacity' method while being more automated to previous one and useful for noise reduction (at least in theory)
Mediana method
Closeup of mediana method
Mediana method with noise reduction
Closeup of mediana method with noise reduction
The conclusion belongs to you :)
My personal opinion is that simple method with noise reduction software works the best for my purposes - however this is my first attempt to usage of 'mediana' and 'opacity' methods so maybe there is some field for improvement. For sure very important factor is the way we develop the RAW image and the visibility of stars versus visibility of noise is a hard balance to reach.
