This is the follow-up to the Milky Way Stars noise reduction: Stars article from a couple days ago. Foreground noise reduction is a different beast and needs to be tamed in a different way. Here’s how I take care of it.
Capture
First is the gathering of the images. In this case, a higher ISO and longer shutter speed are employed. Reference the Histogram on your camera to make sure you are getting enough exposure. It is easy to think you have plenty of exposure if you depend upon the back of the camera. The fact that it is dark and you are viewing a transmissive backlit image can fool your eye. Histogram, make it your friend.
As with the stars capture, I made 10 images of the scene. The OM System cameras have an Interval Shooting Menu. Turn it on and set the number of frames you wish to capture and the length of time between each capture. One thing to watch is to scroll down in the settings and make sure that Interval Mode is set to frames verses time. If it is set to time no matter how many frames you select it will stop to the time set.
Different manufacturers have slightly different nomenclature for this menu.
Why make multiple images of the same scene? In each photo, the noise pattern is slightly different. The difference in each is what makes it possible to process the noise out. I often find using Photoshop’s Median Filter process works better than noise reduction software. But it doesn’t hurt to try both to see what work for your workflow.
Processing
Make any minor tonal adjustments using Adobe Camera RAW or Lightroom if that’s your software of choice. Output the files. I convert to .TIF for this process. Load the files into Photoshop as layers. There is a command in Adobe Bridge as well as one from Lightroom to make this happen automatically.
Once you have the layer stack in Photoshop, select all of the layers. Hold down the CTRL key on the MAC or Right Click on PC. In the resulting dialog box, convert the layers to a Smart Object. Next, navigate to the Layers Menu > Smart Objects > Stack Mode > Median. Noise gone. Nice!
Final thoughts
There are other ways to capture the foreground for your Milky Way image. There could be enough light from some light pollution, a 12% to 20% moon just rising or setting or you can photograph it at blue hour and then wait for the Milky Way to achieve its position within your composition. Choose the one that’s most time efficient and artistically right for your work.
May the clouds, moon and skies be ever in your favor. Let me know how you make out! Post in the comments below.
Yours in Creative Photography,
Bob
