Sunday, January 13, 2013

An Alternative to Noise Reduction Software

Winter is here and some of my most memorable shots were taken during falling snow. The problem I often run into, however, is that, despite all the falling white stuff, it is often very DARK during a snow storm – even in the middle of the day. To compensate for the lack of light, most of us boost the ISO on our cameras, lower the shutter speed, open the aperture and cross our fingers. After a few bone-chilling hours in my blind, I take my precious (hopefully) treasure-filled memory card to the computer, plug it in and start reviewing my photos. Lots of birds, falling snow and NOISE!!!
Yes, noise. Those annoying little spots and flecks of computer-generated junk in the dark areas behind my subjects. Under snowy conditions, there is sometimes so much noise that it is difficult to remove with the noise reduction application that came with my photo processing software or even the expensive plug-in that I bought. RATS!!!



What to do? What to do? I COULD go back outside and shovel the sidewalk to make it safe for the neighborhood children, or I could try to save some of my better photos. No contest – fire up the software. Here is a shot of a Cardinal I took in a recent snow storm. I cranked up the ISO to a modest 640 and used a shutter speed of 1/320 with an aperture of f/6.3. I thought I was safe from noise, but, as you can see from the close-up, I was not. Noise and lots of it! Noise is especially apparent in the dark areas in the background.

Fortunately, the photo is not too dark. If it needed to be lightened, that would introduce even more noise. As it is, most shots taken under these conditions are a little flat and need a slight boost in saturation. Guess what that does? Yup, it puts in even MORE noise.   

For this photo I tried some of the standard Photoshop techniques, including using noise reduction software (it couldn’t get it all out) or blurring the background (I ended up with waves and ghosts). Then, I reverted to a simpler method. First, I made a duplicate layer in Photoshop and set to work adjusting the brightness and contrast of this new layer. I reduced the contrast A LOT – to minus 40 and reduced the brightness to minus 30. I know this is a huge adjustment, but it did get rid of the noise. If you want to get really aggressive, apply your noise reduction software to this layer. The result looks something like this:



Next, I want to get the main subject (the bird) and some of the detail on the larger branches back. I apply a mask and mask off the bird and the branches I want to keep:
 
As you can see in the close-up, there is far less noise in the dark areas of the background:
 
The overall photo is still a little dull (it was rather flat to start with). I fix this by putting BACK some of the brightness and contrast I took out before (about plus 15 for both brightness and contrast) – this introduces very little noise to the now-flat background. I also boosted the saturation a bit – maybe plus 15 to put some color into the bird. If this had been almost any bird other than a bright red Cardinal, I could have gone way up on the saturation. Finished product:
 
Close-up:

Side by side (click Here to see a larger version of this photo:

Close-up (click Here to see a larger version of this photo):
 
Total time – maybe 5 minutes.

Steve Byland is a wildlife photographer living in suburban New Jersey. His photos can be seen at www.stevebyland.com . You can email him at sbbyland@aol.com