post-processing workflow: how to deal with color banding / posterization
If you’ve ever noticed banding or posterization in your photos, where you’d expect solid colors, then there’s a relatively easy fix for it. This posterization effect appears as bands of colors, where the transitions between similar tones aren’t smooth, but have jagged edges instead.
It is caused by the 8-bit JPG not having enough data to give you a smooth gradient when large blocks of color slowly change. You’ll often see it in the blue sky in landscapes, or as in this case, with large areas of color in the background. Actually, the image above doesn’t show this – I fixed it. Here’s how.
1. Working with the 8-bit JPG from the start. You can see that blocky posterization happening therein this 100% crop. This is typically what the color banding looks like – as seen is this 100% crop from the image above. The even tones are broken up.
The trick is to not convert your edited RAW file immediately into JPG. Instead, process your RAW file as a TIFF, or as DNG, which are 16-bit (or higher).
2. The 16-bit TIFF version, converted to JPG only as the final stage, shows reduced banding. In saving for web, the banding is slightly re-introduced but at a lesser extent than working with just a JPG originally. The DNG version also reduced the banding.
working first with a 16-bit image rather than an 8-bit JPG
For most of my usual workflow, I edited the RAW files for Exposure, WB, Contrast and such. The main adjustments (and any heavy lifting) is done with the RAW file which use 12 bits or more, for data. This is obviously a lot more data than an 8-bit JPG has. Then I do finer retouching such as skin retouching, on the JPGs. When you then save and re-open the JPGs, this kind of banding becomes noticeable with some images.
When I work with images that show this kind of banding, I change my workflow. Instead of converting the edited RAW file to JPG, I convert to 16-bit TIFF instead, and then do the retouching. Only at the final stage, do I convert to JPG for web use, or for uploading to a lab. In this way, I work with a 16-bit file for as long as possible.
Lightroom’s latest incarnation allows you to do retouching on the RAW file, so that side-steps much of this altogether.
That’s essentially it – avoid the 8-bit JPG step as far as you can in your workflow. This will greatly reduce the chances of seeing this kind of color banding. As if you needed more reason to shoot in RAW!
Of course, since this is Photoshop, I am sure there are other ways of dealing with this. If you have another method that works, let us know.
lighting setup & techie details of the main photo
Above is the (nearly) original image, not cropped to a square format. I have to say “nearly” because I missed the composition while shooting in the studio. I chopped a fingertip off.
I really liked Anita’s pose here. So I cloned in the fingertip in from another finger in Photoshop. And then finessed the extra width of the image via Photoshop’s Content Aware Fill. Whoever at Adobe came up with Content-Aware Fill, is a genius. Also, whoever devised the Healing Tool, should be nominated for a Nobel Prize for awesomeness.
The colored lights are from two speedlights in the background, with colored gels over them.
equipment used during this photo session
- camera settings: 1/200 @ f/4 @ 200 ISO
- Nikon D4; Nikon 70-200mm f2.8 AF-S VR II used at 135mm
- Profoto D1 Air 500 W/s Monolight
- Profoto beauty dish with a Profoto Honeycomb Grid, 25 Degrees
- (2x) Nikon SB-910 Speedlight
related articles & links
- more articles on digital imaging & workflow
- colored gels with flash photography (model: Jessica Joy)
- studio photography – using a big gridded strip-box / soft-box (model: Anita De Bauch)
- posing tips: pose the hands – asymmetry (model: Anita DeBauch)
- photo session w/ model Anita DeBauch
- NJ photo studio rental