Sunday, 12 April 2015

Quick Techniques For Reducing Banding / Posterization in Photoshop - BRUSH STROKES

Posterization – Rough Techniques For Reducing Banding!

Notice the subtle rings around the soft brush?

What is it?

If like me you work as illustrator/designer, I’m sure you will have run into the dreaded banding aka Posterization If so, I will go into detail shortly. Please note; this is told from an illustration and design bias.

Illustration in Photoshop has been a blessing for me. Edit, undo, save as, copy, paste, re-colour artwork the list goes on. This issue comes when working with radial and linear gradients and tones of black and grey. Working with a lot of black and orange as part of the colour palette, I have had to figure out ways for dealing with or working around banding. For example, when I’m rendering characters like Rufus the rat, he has grey body with even darker creases in the body, getting the shading and highlights to blend hasn't always been easy - banding has been a big issue. As it stands, I’m still uncertain as to how to get a completely smooth finish when rendering by work with a grey and black tones. I can offer some methods for reducing this so called ‘banding’ effect and the bane of drawing Rufus. 

For additional information this has been written based on the specs of the my iMac - OSX, but this issue has proven to effective on a TFT Screen using windows 7 and older versions of PS.

My Setup 1 : New Document ‘I like RGB’

From the off I have tested this on Photoshop CS5 and CC with similar results from version to version. 64 bit – 32 bit RGB to CMYK I’m not entirely sure if this has an influence aside from whether you are working with 8 bit, 16 bit and 32 bit; the later offering marginally tighter rings and hues. For this example I have worked with A 300 DPI document, in RGB using 8 bit (this can be changed later) also with the colour profile listed below on an iMac. This is by no means a significant contribution to the final out come but maybe worth noting. 

‘tangent alert’
 Using RGB in the early stages is my preferred method, not everybody’s. Isn’t this madness? You won’t see genuine colours of your artwork! Well unless, your screen is calibrated exactly and your using pantones, guaranteeing what you see on the screen to print can be tricky anyway. Besides, I work across both mediums of screen and print. 

Method 2 :  Ultimate Trick - Brush & Noise

I’m assuming that you are running into this issue whilst using a soft edged brush tool in Photoshop, based on that, I would advise turning the 'noise' on under the brush panel (as shown - press F5 bring this window up) this helps in the blending of steps with greys as shown below. As far as I can tell, based on my work, this improved the overall smoothness and graduation of the tones from light to dark regardless of bit mode or any other. You can also dabble with the filters if you are using large radials (That would be a different article). 
As you can see below, the black brush at the top has rings (banding) and the one below has far fewer the brush used on the lowest part of the blob has noise switched on. The speckled effect will be less obvious once you take your artwork to print.

See how the rings blend together of the lower part of the blob?

Method 3 : Big to small, playing with scale

Another trick for tightening this banding is by shrinking/scaling down your completed artwork. When you have applied the 'noise' and finished the process you can physically shrink the image to hide some of the messier details - an illusion essentially. 

This is a method that I have used not only to disguise banding when digitally painting but also to give the appearance of tighter line work and detail.

Step 1 piece of art = 100%
Step 2 scale art to = 75%

So when you print the document some so the details and blemishes are hidden away from the naked eye. This approach can also hide some of the rings in banding with added element of noise!

You will see the benefits for this when you come to printing your work, especially if you are working with shades of grey.

To summarise - Add noise to your brush mode.

Hope this helps!

This method was used when illustrating/digitally painting Rufus the Rat for Satzuma LTD

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