In photography, there are 4 key words to understand that help produce high-quality images. They are
Each of these words refers to a specific issue that can affect the quality of a photograph. In this article, I’m going to define and explain each of these terms and provide some tips for preventing or fixing them to help you avoid a loss of quality in your images when shooting in different conditions.
Banding is a phenomenon that occurs when there are visible horizontal or vertical lines in an image.
These lines can be seen as lighter or darker stripes that run across the photo. Banding is generally caused by uneven lighting, incorrect exposure settings, or compression artefacts.
It can also happen when shooting with certain types of artificial lighting, such as fluorescent or LED lights.
When it comes to digital photography, banding is more noticeable in images that have been compressed or saved in a lossy format such as JPG.
This is because compression algorithms discard some of the image data to reduce the file size. If too much data is lost, the image can become pixelated, and banding can occur.
To avoid banding, you should use appropriate exposure settings, avoid compression, and ensure you shoot with enough light and not rely on the ISO.
Banding can be corrected in post-processing using a variety of techniques. For example, a photographer can try adjusting the brightness and contrast settings or using noise reduction software.
Artefacts are another issue that can affect the overall image quality of a photograph. An artefact refers to any distortion or anomaly that appears in an image. These distortions can occur due to various factors, such as compression, over-sharpening, or incorrect exposure settings.
Some of the most common artefacts include blockiness, halos, and posterization.
Blockiness is when an image appears as if it has been divided into blocks, and the transitions between these blocks are not smooth.
Halos are rings of light or dark that appear around objects in an image, often caused by over-sharpening. Posterization is when an image appears to have fewer colours than it should, leading to a loss of detail and a flat, unnatural appearance.
To avoid artefacts, photographers should set the best possible exposure, avoid over-sharpening, and ensure that they are using the correct file format. Some artefacts, such as posterization, can be difficult to correct in post-processing.
Pixelation is a term that describes the appearance of an image when it has been enlarged beyond its resolution capabilities.
When an image is pixelated, it appears with visible square pixels that are easy to see.
Pixelation can occur when an image is enlarged too much or when the resolution of the image is too low for the size it is being displayed at.
In digital photography, pixelation can occur when an image is cropped too tightly or when it is enlarged beyond its original size. It can also occur when an image is saved in a format, such as JPG, that compresses and reduces the amount of data that can be displayed.
To avoid pixelation, photographers should ensure that they are using an appropriate file format and resolution for the size of the image they need.
When enlarging an image, it is best to use software that can scale the image without losing quality, such as Adobe Photoshop.
Do not make your image dimensions substantially larger than the native file that comes out of your camera.
For example, upscaling (making a digital image larger) from 2,000px on the horizontal to 4,000px on the same axis runs the risk of pixelation.
Extra pixels aren’t magically added to fill the gaps, instead, the existing pixels are stretched to fit the size causing a distortion in the image quality. If an image is pixelated despite these precautions, it may not be possible to correct the issue in post-processing.
Moire is a phenomenon that occurs when there is interference between two regular patterns. In photography, moire can occur when an image contains a repeating pattern that interferes with the sensor’s regular pattern of pixels. This interference can cause a wavy or distorted pattern to appear in the image.
Moire is most common when photographing fabrics or other materials that have a regular pattern or texture.
For example, if a photographer takes a photo of a shirt with a fine-checked pattern, moire may appear in the image as a series of wavy lines or patterns.
To avoid moire, change the angle or distance of the camera from the subject. Another way is to use an anti-aliasing filter on the lens, which can help to smooth out the image and reduce the likelihood of moire appearing.
An anti-aliasing filter works by slightly blurring the image, which helps to prevent interference between the sensor and the repeating pattern in the subject.
Some camera manufacturers have stopped including anti-aliasing filters in their cameras, as they can slightly reduce image sharpness.
If moire appears in an image despite these precautions, it can be corrected in post-processing using software such as Photoshop. One way for removing moire is to use a blur filter, which can smooth out the image and reduce the visibility of the moire pattern.
In conclusion, understanding the technical terms of photography, such as banding, artefacts, pixelation, and moire, is essential for avoiding a loss in your image quality as a photographer. If you want the best-looking photo in a variation of different sizes ensure you’re following these guidelines.
By avoiding or correcting these issues, photographers can ensure that their images are clear, sharp, and free from distortion or interference. With the right techniques and tools, it is possible to produce stunning photographs that capture the beauty and essence of the subject.