If you have ever taken long exposures, or shot in dimly lit areas, you have most likely run into the problem of having noise in your photograph. Despite the fact camera manufacturers are actively trying to reduce noise, this still remains a legitimate problem. The following tutorial will show you step by step instructions on how to use the software Noise Ninja to remove excessive noise from your photographs.
The top 3 reasons you might encounter noise in your photographs are: Use of a high ISO, long exposures, and dimly lit areas. While there are a few options when it comes to noise removal software, I have chosen to write about Noise Ninja as it is a product I use on a regular basis, and I have been extremely satisfied with the results. Reducing noise is important in large prints because it is easy to see, as well as in web sized images because any sharpening you do to your image will be negatively impacted if your image has excess noise.
For the following tutorial, I will be using a photograph that was taken inside a reptile zoo, where the lighting is considerably dark. The photo was shot at f/3.2 for 1/80 sec at 1250 ISO. I would consider the amount of noise in this photograph to be significant, but certainly not the worst I have dealt with.
The image above is the photo we will be editing for this tutorial. It has been re-sized in order to fit within the screen. We will be applying Noise Ninja to the image at full resolution however. Instead of showing you the entire photograph at 100% zoom, we have instead cropped 3 areas of the photo, and shown their states, before and after Noise Ninja was applied.
The background is extremely out of focus. Nothing ruins the beauty of negative space like noise texture. We recommend leaving some texture otherwise your image will be too blurry.
Due to the shallow depth of field, this area is out of focus. The texture of the noise really becomes annoying.
It may be hard to tell by comparing these two photos side by side, but believe me when I say that when noise is removed, the lines in the photograph become more distinct and clear. When you overlay both images and toggle the top layer, it is easier to see the difference.
Let’s get started.
Noise Ninja Tutorial
I’m going to assume you already have Noise Ninja installed. For the purposes of this tutorial we will be using the Noise Ninja Photoshop Plug In. Again, I always recommend editing your image at full resolution, then resizing based on your needs afterward. With the exception of tweaking values in a RAW importer, you should use Noise Ninja before you move on to any other type of editing.
Step 1 – Choose your image and open it in Photoshop by going to File->Open
Step 2 – With your Background Layer selected, go to Layer->Duplicate Layer… . Click OK.
Step 3 – With the Top Layer Selected, go to Filter->Picture Code->Noise Ninja… . This will open up the Noise Ninja interface. The large main window will display your photograph in it’s natural state. The small window at top right will show you what your image will look like after Noise Ninja is applied. I like to keep the windows at their default zoom factor so that I can choose specific areas of the image using the big window, and see what they look like in detail after processing in the small window.
Step 4 – Select the Cross Hair tool at the bottom of the window (circled in red). Now within the main window, select a region with noise so we can compare the before and after in the smaller window. Next, select the Filter Tab.
Step 5 – Instead of gradually increasing the values, we are going to set them to their strongest setting and work our way backwards. Adjust the Luminance Strength and Smoothness settings to a value of 20. If you look at the smaller window, you will notice that your photo probably looks too blurry and not in focus. Gradually reduce the Strength value while watching the small window. Keep reducing it until you are satisfied with the amount of visible noise. I recommend choosing a value that shows some texture (not completely blurred). We decided on a Strength value of 14.
Step 6 – Next we will adjust the Smoothness setting. You will want to reduce this slider until you start to see “splotchy pixels groups”. Once you see them, increase the value until they disappear. This value should generally be lower than the Strength value. We decided on a Smoothness value of 7, but this may be different depending on the amount of noise in your photograph. View the image below to see what we mean by “splotchy pixel groups”.
Step 7 – Next, select the Noise Brush tab. This will allow you to selectively mask areas that you think require specific treatment. Using the Paint Mask mode will allow you to reveal parts of the image as they were originally (without Noise Ninja applied). Using the Erase Mask mode will allow you to paint back in areas you want Noise Ninja to be applied. In order to paint the mask, you will need to have the Paintbrush Tool selected (circled in red). Feel free to adjust the brush radius and strength. I rarely use this feature as I find the noise is generally consistent throughout the photograph, which is why I will not go into much detail about using it. I did however want you to know this tool is available.
Step 8 – Once you are happy with your settings, click OK (circled in red). Noise Ninja will apply your settings, and take you back to your Photoshop document.
Now that you have applied Noise Ninja, toggle the top layer of your document so that you can compare your image’s before and after states. If you are happy with the results, continue with your regular editing work flow. If you are not satisfied, start over.
If at anytime you get stuck, you can click on the Question Mark Cursor (circled in green in the image above), then Select any of the tools or settings in Noise Ninja. A pop up window will give you a detailed explanation of the tool/setting in question.
I hope you have found this tutorial helpful.
Link: Noise Ninja Website