Photoshop Tip Of The Month: Digital Noise? Nik Dfine To the Rescue
Rating: 7 / 10All digital cameras introduce noise into a capture. Optimizing and refining images with Nik products is fast, effective and efficient. See how we use Nik Dfine to reduce digital noise...
All digital cameras introduce noise into a capture. Factors that contribute to the amount are ISO, length of exposure, underexposure, size of the sensor, and how much cropping is done to the file.
- The higher the ISO, the more noise.
- Exposures of two seconds and longer introduce noise.
- If a digital capture is underexposed, corrections in post processing introduces noise, especially in the shadow areas.
- The smaller the sensor, the more noise.
- The more a file is cropped, noise becomes more of an issue.
Noise comes in two forms - Luminance noise and Color noise. Luminance takes on the appearance of film grain while color noise appears in the form of odd looking rainbow colored speckles. Both detract from the overall quality and appearance of a photo. Thankfully there are software programs that circumvent these effects. My “go to” is Nik Dfine 2.0. It’s so good at what it does, the majority of time I let the program run the Automatic feature and simply click OK.
If a slide is scanned, reducing noise is a bit trickier as film grain is viewed as noise and is quite noticeable. This is when I take advantage of the Control Point or Color Range technology. Regardless of which method is used, the amount of reduction of luminance and color noise can be finessed from 0% up to 200%. Adjusting the amount based on color, texture, exposure or a combination of all three allows me to finesse very specific areas of the image to provide the exact rendering of noise reduction I desire.
BEFORE Dfine Applied
AFTER Dfine Applied
THE Nik Dfine 2.0 USER INTERFACE
The user interface is straight forward. The key features are found on the right side in the Noise Reduction Panel. In the Method pull down menu, there are two choices: Automatic/Manual. Automatic appears by default and I recommend using it for the majority of your work.
To access the Control Point and Color Range options, click the REDUCE button. Next to the word METHOD, click the down arrow to choose either the Control Point or Color Range method. I find Color Range to be very useful if I want to reduce just the noise in a blue sky.
At the bottom right side of the panel is a navigator. If the image is zoomed, drag the red square to the point in the image you want to see in the main picture area.
Luminance Noise From an ISO 400 Capture With Slight Underexposure.
AUTOMATIC METHOD APPLIED
BEFORE Dfine Applied
AFTER Dfine Applied
On the above screen shot of the user interface, note the three white squares the software automatically placed within the image. The software looks for smooth parts of the photo that reveal noise. Based on the “grittiness” it finds, it automatically and magically reduces the noise but still retains all image sharpness.
If you like what you see in the Automatic mode, simply click the OK button on the bottom right and let the software process the image.
The Navigator window can be used as a Preview box. In the main window, move the cursor around and the corresponding view in the Navigator window will be at 100%. All important parts of the image can be quickly previewed. I find this to be quick and efficient.
To the left of the red line is the BEFORE view and to the right is the AFTER. Look at the screen shot of the before/after view. The noise is completely removed in the blue water yet the fine detail in the hairs of the duckling remain sharp.
Luminance Noise From a High ISO Capture of 1600.
AUTOMATIC METHOD APPLIED
The image of the offering candles was made at ISO 1600 with a Lensbaby to provide a slight vignette, mostly along the bottom edge. Viewed at 100%, the file is quite noisy. Note the number of squares the software placed on this file. There are a total of five. You’ll find that the number of target squares Dfine places will vary from image to image. It all depends on how many areas of noise the algorithms detect.
The navigator window shows the before and after view. Look at how creamy and smooth the after image looks in comparison, yet the sharpness level remains the same.
The BEFORE and AFTER images are at 100%.
When a slide is scanned, the grain takes on the appearance of digital noise. For this image I wanted to restrict the noise reduction to the water area so I chose the Color Range method and targeted blue. But some of the blue color spilled over to the head of the pelican so I used the following steps to remove the noise from the image.
I opened the slide scan of the pelican in PS and set the magnification to 100% by double clicking the zoom tool. I make this part of my workflow as it allows me to immediately see the effect Dfine applies after I click OK.
My noise reduction goal for this file was to remove all the grain from the water but not the pelican. I opted to use the Color Range method and did so by clicking on the REDUCE button and then going to the pull down arrow next to METHOD and choosing Color Range.
In that I wanted to target the blue, I clicked on the top eyedropper and moved it to a light shade of blue on the image area. To cover all tones of the water, I did the same for the dark shade of blue using the second eyedropper. I moved the Contrast Noise sliders (luminance) to values of 149% and 151% to ensure I’d smooth out the grain in the water. These values can be tweaked to attain the necessary amount of noise reduction.
Note the creaminess in the water in the after view in the navigator window.
In exploring the rest of the image using the navigator, I noticed some noise reduction spilled onto other colors. To remove it from those areas, I added additional Color Range points using the + button to create more eye droppers. I used the eyedropper to click on those colors in the image area and moved both sliders to the left to values of zero%. By moving the slider to zero, all noise reduction from that color was canceled.
Take a look at the fabulous job this method produced. The feathers remained tack sharp yet the water that contained an immense amount of grain now appears creamy and smooth.
I’ve been a long time user of the Nik product line and a proponent of all their software programs. Like most photographers, I prefer to be out in the field and Nik software provides me this opportunity as I don’t have to spend as much time in front of the computer. Optimizing and refining my images with Nik products is fast, effective and efficient.
Check TGP at the beginning of every month for a new Photoshop Tip Of The Month. Visit www.russburdenphotography.com for information about his Nature Photo Tours across the US.