Banding

THE DIFFERENCE BETWEEN 8-BITS AND 16-BITS

In order to explain the operation of an 8-bit and 16-bit working environment, we will start immediately with a difference. The difference between JPEG and RAW.
If you shoot in JPEG, you will only be able to work in an 8-bit work environment while editing your photos in a photo editing program.
If you shoot in RAW, you can choose between 8-bit or a 16-bit working environment.

In most cases, colors are central in photography.
The well-known RGB colors stand for Red, Green and Blue.
With these three colors you can get a lot of colors by “mixing”.
Here we come straight to a second difference.
With 16-bit we can make many more combinations (shades) than in an 8-bit work environment.

AN 8-BIT WORK ENVIRONMENT

Various types of shades can therefore arise from the colors mentioned above.
Think, for example, of light green to dark green and all shades in between.
We know from the mathematical formula behind the operation of bits that these are 256 shades.
In computer language, bits can have two values: 0 and 1. To calculate the number of shades, you get the following sum 2x2x2x2x2x2x2x2 = 256.
So 256 shades of green, 256 shades of red and 256 shades of blue.
If we mix these shades together (multiply) you get 256 x 256 x 256 = 16.7 million different shades.

A 16-BIT WORK ENVIRONMENT

Above I have described the effect of the different shades. However, the above described applies to an 8-bit working environment.
If you work in a 16-bit work environment, even more shades are possible, namely 65536 shades per color! A difference of no less than 65280 shades with the 8-bit working environment.
To calculate the total number of shades of a 16-bit work environment, you get the sum:
65536 x 65536 x 65536 = 281 trillion different shades.
See here the third difference between an 8-bit and a 16-bit work environment.

IN PRACTICE

Although it is all about details, there is a difference between an 8-bit and a 16-bit work environment.
If we zoom in strongly on a gradient from gray to white at 16-bits, we still see a nice gradient, while at 8-bits we see a gradient in stripes, also called “banding”.
This has to do with the number of shades. Because the shades are more limited in an 8-bit work environment, you will see the transition to a different shade “jumps”, while in a 16-bit work environment the transition is “smoother”.

Suppose you are editing a photo in your photo editing program in an 8-bit work environment. You would like to crop the photo, but “banding” (nasty stripes / spots) will occur in your photo.
This has to do with the transition from one shade to another. By working in a 16-bit work environment you will not get these stripes / spots.
In an 8-bit work environment there are only 256 shades to make a gradient, while in a 16-bit work environment it is 65536 shades.

8-BITS VERSUS 16-BITS!

Although you will normally not see any major differences, you can conclude that in a 16-bit work environment you have more options, especially in the smallest details.
By setting your camera to RAW, you automatically get a 16-bit in the editing of your photo.
(In JPEG you can only edit the photo in an 8-bit workspace).
So a problem can arise here …
So if you edit a photo in RAW and use too many color tones, for example, banding may occur in the JPEG photo.

What is “banding”?

Banding is the term for finding unwanted patterns or vertical stripes in a photo.
The unwanted lines can be vertical or horizontal, depending on the camera position at the time the photo was taken. Banding is often caused by a color resolution of 8 bit per base color that is too low.
Photos are stored in bits.
As explained above, more bits produce a higher quality of your photo.
You can of course take a photo in 8 bits, which saves disk space, but I always want the best quality and the most options during editing, so I do want to have 16-bit RAW files.

Thorough editing of a JPEG photo will therefore result in banding rather than your RAW file. A very high ISO value can also cause banding.

Also take into account the screen on which you are viewing the photos.
It also has a color depth (bits) that can influence how you see the photo.

Saving a RAW photo in JPEG means that the photo will be compressed (smaller in size).

During compression, contrasts and colors that are close to each other are merged, resulting in banding instead of gradual transitions.
If the contrast depth is too small (high compression), then with gradual color transitions (eg clouds) “banding” will be visible.
Banding can also be caused by manipulation of the histogram (eg increasing the brightness if the original photo is too dim).
By “stretching” the histogram, fields of equal intensity are created instead of smooth transitions.

An exaggerated example of “Banding”

 

Prevent

In post-processing it is important to check whether your RAW photo is edited in 8 or 16-bit.
You can save the photo as 16 bit TIFF.
However, if you are going to upload the photo to social media or the like, it will have to be converted to 8 bits JPEG.
If you want to continue editing, make sure that you are working in the 16-bit color depth again.
This often means going back to your RAW or PSD file.
It can also help to add some ‘noise’ in post-processing, but the question is whether you want that.

  • Make sure your ISO is low.
  • Photograph and edit in RAW with the highest possible resolution (max. What the camera can handle) and contrast depth (16-bit)
  • Always work with 16-bit contrast depth in Photoshop
  • Save the RAW files so that any subsequent photo editing can also be done in RAW.
  • Converting an 8bit jpg to 16bit / color (Image-Mode-16bit / channel) can help to avoid banding when manipulating the histogram.
  • Limit manipulation of the histogram.
  • Correcting underexposed images can cause banding.
  • Always convert to JPEG as the last operation.
  • To resize the photo, reduce the number of pixels but save in maximum quality (contrast depth).

 

Handtekening Chris