Does the photo look dirty and fuzzy? Feeling like the image is filled with noise, but you can’t see the details? Does an old film effect appear that you did not plan? Most likely, we are talking about a defect called noise.
We figure out what it is, why there is noise in the photo and — most importantly — how to remove it.
What is noise and why does it occur
Noise is a defect in photography. It manifests itself in the fact that small randomly scattered pixels appear in the picture. Because of this, where the surface should be smooth, monophonic, or there should be emptiness at all (for example, the night sky), there is a feeling of “roughness”, fuzziness. It shows up especially well when an initially dark frame is heavily lightened in post-processing.
Noise is of two types:
1. Colored. In this case, the pixels scattered over the image are colored in different colors.
The easiest way to remove such noise is to discolor it in a special way in a graphic editor in a couple of seconds.
If you reduce this noise in the photo, it will inevitably lose sharpness. This is due to the fact that luminance noise is removed by blurring the image. Therefore, it is believed that such noise is more difficult to remove, and sometimes even impossible. Naturally, if you do not want to lose quality.
Sometimes it’s easier to prevent a problem than to fix it later. If you know why noises appear, you can take action in advance and reduce the chance of their occurrence. Let’s take a look at the most common reasons.
Why there is noise in the photo
- Too high ISO.
Noise occurs where there is not enough light. In this case, the photographer falls into the trap — he needs a lighter frame, but if he raises the ISO, the quality will drop. You should either put up with this, or look after yourself with a fast lens.
- The state of the camera matrix.
The matrix may be physically damaged. For example, it may have broken pixels. This is the name of “broken” pixels that do not transmit color or always shine with some one color — red, green, blue.
- Matrix pixel size.
The bigger it is, the better. Often this value is indicated in the characteristics of the camera, if not, in this text we tell in detail how to calculate the physical size of a pixel ourselves.
- Camera and lenses designed for amateurs.
As a rule, the more expensive the camera, the larger the pixel size, as well as the higher the ISO setting that the camera allows you to set. Where an amateur camera feels insecure at ISO 800, another calmly shoots at ISO 1200–1600 without noise and loss of quality.
Professional lenses also produce better image quality than their budget counterparts. This is the case when you overpay not for marketing, but for better technology. In addition, only in more expensive models you can find truly fast cf / 2.8 glasses and below. The lower this number, the darker conditions you can shoot without bumping up the ISO.
- Wrong post-processing.
Noise may appear if in the graphics editor:
- raise the exposure too much;
- radically brighten dark areas;
- increase sharpness;
- increase the saturation — this highlights the color noise;
- when editing white balance. For example, you want to remove cold blue from a photo and naturally add yellow for this. In this case, the yellow noise that was in the picture will intensify.
How to remove noise from a photo
We will look at the easiest and fastest ways to remove noise from a photo using image editors. But remember two things:
- it is not always possible to remove noise completely;
- get ready that the suppression of luminance noise will “kill” the sharpness of the image.
How to Remove Noise from a Photo in Photoshop
1. Open a photo and make a duplicate of the original layer. To do this, right-click and search for the command Duplicate layer / Duplicate layer (Hotkeys Ctrl+J).
2. Stand on the duplicate layer by clicking on it. Go to menu Filter / Filter — Camera RAW filter / Camera Raw Filter (Hotkeys Shift+Ctrl+A).
3. Find a tab Detail and two groups of sliders in it: Noise Removal / ND and Color Noise Removal / Color ND. The first group is responsible for the luminance noise that creates graininess, and the second group is responsible for the color noise.
Both groups have three sliders:
one. Noise Removal / ND and Color Noise Removal / Color ND.
Luminance noise is removed by blurring, and color noise is removed by desaturation and color blur. This is the main noise removal slider.
2. Detail / Detail.
Attempts to maintain the sharpness that the previous slider removed. The larger the value of the slider, the more noise will be returned to the image.
In a group Color Noise Removal / Color ND this slider protects color transitions. This is necessary so that the discoloration concerns only noise and does not creep onto the model, clothes, interior.
3. Contrast / Contrast.
The higher the value, the higher the image contrast that the first slider could remove. High values can show dirt in the picture — spots, graininess.
How to Remove Noise in Lightroom
Noise removal in Lightroom is very similar to the same algorithm in Photoshop. The fact is that Lightroom is a complete analog of Adobe Camera Raw, but only with a slightly modified interface.
1. Open a snapshot and go to the tab Development / Develop.
2. In the settings panel on the right, find the tab Detail / Detail.
3. In the Detail tab, find the column Noise Reduction / Noise Reduction.
Slider Brightness / Luminance responsible for luminance noise, and Color — for colored ones. These are the basic tools for noise reduction.
sliders Detailas in Photoshop, set the threshold for the effect, bringing back detail and—often—noise too.
Slider Contrast / Contrast returns the contrast of the image, and Smoothness / Smoothness for colored noise sets the smoothness of the transition between colors, does not allow the tool to discolor third-party objects, except for noise.
How to take photos without noise — 5 tips
1. Increase your shutter speed instead of ISO and shoot from a tripod.
2. Use additional light if possible. Even the cheapest external flash on the report will raise the quality of the pictures and reduce the noise.
3. Keep a fast lens (f / 2.8 or less) in your arsenal in case of shooting in poor light. For example, in concert halls, theaters, it is forbidden to use a flash so as not to distract the artists.
4. When choosing a camera, give preference to the one with a larger pixel matrix. For example, a Nikon D610 camera with a 35.9 x 24 mm sensor or a Canon EOS R6 mirrorless camera with a 35.9 x 23.9 mm sensor.
5. Shoot in RAW, not JPEG. In post-processing, it will be easier to “stretch” the image without losing quality.