Digital noise: causes, types and ways to get rid of
Digital noise: causes, types and ways to get rid of
Anonim

Modern technologies allow people to enjoy pictures and photographs that, in fact, do not differ from reality. They incredibly accurately convey the whole essence of what is happening, they have no interference, blurring, bumps and other defects. But sometimes, when you take a picture with a new, high-quality camera, you get a picture with digital noise. What to do in such situations and how to deal with it?

What is this?

Before we begin to explain certain phenomena in the world of photography in scientific terms, let's simplify the task a bit. Remember how before (before the advent of satellite dishes that tell us "no signal") untuned channels looked like. The entire screen was filled with a kind of "white noise", the so-called waves, which do not transform into an image, but exist in a chaotic manner. They are predominantly black and white, and if you adjust the volume in the audible range, you can hear a characteristic sound. Digital noise is what this phenomenon is called,whose roots descend into the nature of photons, in particular their vital activity.

A similar defect can be found in the photographs. Often we have seen pictures that are completely or partially covered with "fine sand" - dots of different sizes and different colors. They may not match the palette of the photograph, which is why they are striking. Photographers, despite the latest developments in digital technology, still face digital noise.

The sound of digital noise

Film and digital

Let's go back to the 20th century for a moment. Then we shot on film "soap dishes" and "reflex cameras", then the pictures were developed in the laboratory, and such a phenomenon as graininess was very common. You can even notice the gradation - the older the photo, the more "sand" in it, which distracts the eye from the main picture. But in the old days, people were content with this, because, in principle, photography was a breakthrough. Over time, everything began to change. Fine-grained films appeared on the market, which had low light sensitivity, which made it possible to visually reduce digital noise. We also struggled with this phenomenon by a special technique for developing images, which made it possible to reduce this defect. The advent of digital cameras did not solve the problem. It turned out that it was not the film that was at all to blame for such deviations, but the very photons that are refracted and literally "fall" on the image in a chaotic manner.

old grainy photograph

Varieties

There are two typesdivision of digital noise when it comes to modern cameras. Here is the first one:

  • Permanent. Appears as a uniform dot of a specific size, color and shape, which is present in all photographs in a certain place. It's all about the "hot" or "broken" pixels that you have in your camera. Most often, such a defect appears during long exposures, when the device overheats.
  • Random. He looks different in every new photo. The dots have a different size, color, and are always scattered in a new way in the picture. Such digital noise is most clearly visible on plain surfaces - skin, sky, curtains, etc.

Also, photographers divide this defect according to a different scheme:

  • Luminance noise - appears in the form of inconspicuous black dots and is randomly scattered throughout the image. Reminds me of that same film grain.
  • Chromatic noise is bright dots of a color that is different from the photograph's palette. It catches the eye and ruins the whole picture.
Digital noise in a photo

Reasons for appearance

It is not enough to know how to get rid of digital noise, you should first familiarize yourself with the nature of its appearance. Here are some reasons that can become the source of such a defect:

  • The small dimensions of the photosensor, combined with high resolution, increase the noise level for a particular matrix. Therefore, do not chase pixels, it is better to make sure that their characteristics correspond to the parameters of the lens.
  • ISO, or sensor sensitivity. The higher shethe more likely it is to get a noisy image. Initially, familiarize yourself with the acceptable ISO range for your camera, and then adjust it manually.
  • Excerpt. The longer it is, the more the device heats up, therefore, interference appears.

Now we come to the main question: how to remove digital noise? This process is divided into two stages: the noise is neutralized at the time of the picture and then "overwritten" or suppressed during editing.

Strong noise in the photo

Stage one

It is better to solve problems of this kind in advance, because later on the finished photo, no matter how successful it may turn out, it may not be possible to remove all the defects. Therefore, before taking a picture, carefully prepare for the process.

  • Reduce photosensitivity - ISO.
  • Slow down shutter speed.
  • Expanding the aperture of the lens.
  • Use additional lighting, like a flash.
  • Almost all cameras have a "noise reduction" function. It adjusts to the ISO and exposure time you set and cleans up the pictures as much as possible, removing all unnecessary spots and dots from them. But at very high sensitivity and shutter speeds, this technology may be ineffective. It will only partially clean up the image, and at the same time some "echoes" of noise will still remain.
  • We shoot in RAW format. The fact is that this format contains more information about the photo, therefore, with further editing, you can get rid of all errors more efficiently.
Photos before and after noise reduction

Stage Two

Next comes the suppression of digital noise with the help of special editors and plug-ins that are installed in the programs. There is nothing complicated in this process, professionals have long learned to deal with such a defect. Let's find out how they do it.

  • You can get rid of noise with the built-in functions of "Photoshop" standard or Adobe Photoshop Lightroom.
  • There are some macros or actions that are used in parallel with "Photoshop" Their main goal is to cope with digital noise and clean up the photo from interference.
  • There are many plugins that are also created specifically to deal with this kind of defects. These are Akvis Noise Buster, Noise Ninja, Neat Image and many more.
  • Use a RAW file converter. There are many additional tools that reduce noise, such as Adobe Camera Raw.
  • Digital noise is also removed by reducing the image resolution after it has been fully processed. In fact, after resizing, the size of the noise remains the same, only now it becomes less noticeable, since the photo no longer has such a high resolution.
Noise visible when image is enlarged

Photography and its features

It is well known that the highly sensitive optics with which we take pictures "see" much more than the human eye. Agree that when looking at a beautiful landscape, you see everything clearly (from yourpoint of view), there is no interference, gradation, the picture is just perfect. You want to capture it with a camera, and you already see noises in the finished picture - how did they get there? Yes, if we are talking about constant noise, then it's a matter of technique, but when the photo is strewn with "sand", and even multi-colored, the question arises: what is it?

The fact is that photons are constantly "flying" in front of us, which we simply do not see. A sensitive lens "swallows" them and displays them on a photograph. If you increase the lighting, the photons will become less visible - they will light up, and the image will become as clear as you see it. That's the whole trick - just the camera sees a little more than you and I.

Conclusion

In order for your photos to be as clear, bright and free of defects as possible, set up your camera before shooting and carefully edit the finished shots. There are many programs and settings, get used to one of them - and you can take the most amazing photos in the world that everyone will love and appreciate.

Popular topic