Not achieving smooth gradient in CS3

[Paul...@adobeforums.com]

Hi

I'm simply trying to set up a gradient in Photoshop CS3, which blends from left to right on an A4 page. The gradient at the left is 15 per cent of Pantone 329C, the one on the right is 15 per cent of Pantone 2617C.

Once I do this however, I can see irregular, vertical 'banding' on the gradient. I've tried printing this out and the banding is clearly evident on the proof.

I've tried exactly the same process in Illustrator CS3 and the result is exactly the same - clear banding visible both on screen and in print.

Am I doing something wrong?

Many thanks for any help.

[Buko]

Ed explained it quite well.

adding some noise will help also you can go into 16bit but if this is to be printed coming back to 8bit may put you right back where you started.

[Scott_W...@adobeforums.com]

Could be the monitor as well, which would further accentuate the banding. Laptop monitors are simply not capable of rendering all the colors natively that a desktop monitor can.

[Neil_...@adobeforums.com]

Paul,

Try different noise and blurring combinations -- you may find one that works a little better. But remember, looking at the effect close up is different from the way your eye sees it in final size reproduction.

Neil

[Paul...@adobeforums.com]

Hi Ed

It's A4 - so 210mm wide x 297mm deep and the gradient runs from left to right. Seems a pathetically simple requirement for both Photoshop and Illustrator not to be able to cope with?

I'll try the noise/blur treatment.

Thanks for your reply.

[Buko]

Also keep in mind that if this is going to print on a printing press you will have the same banding problems with such a short gradient. This is not a Photoshop problem it is a physics thing.

[Ed Hannigan]

It's not a matter of Photoshop or Illustrator not coping with it. It's universal. Long gradients produce banding, regardless of what software is used. There are a limited number of colors/shades of gray and when you stretch it out too long or the percentage of change is not enough, smooth transitions are no longer possible.

I'm sure someone else can provide a more "scientific" explanation.

[Paul...@adobeforums.com]

It's really disappointing this. I can partially remove the banding by using noise and then blur, but it's not a complete success. It's also changing the colour balance, so I've now got to compensate by using a stronger tint than 15 per cent to begin with.

I hadn't realised that such a simple thing could be such a pain!

Thank you all for your help.

[PSh...@adobeforums.com]

Another thing you might try is to convert the image to 16 bit mode before creating the gradient. Switch back to 8 bit and apply the noise/blur routine (note that the blur is to subdue the noise - blurring alone does nothing to help banding).

[Ed Hannigan]

How long is the gradient? Banding will occur if the length is too much. Not much you can do bsides tweak it by adding a small amount of noise and Gaussian Blur.

[Ed Hannigan]

Right. I have found that sometimes the noise "graininess" is visible (especially on screen), hence the blur. But in some cases noise alone is sufficient.

[Ernes...@adobeforums.com]

Reset the preference file, press CMD+ALT+SHIFT when starting photoshop and press OK

[Steve_...@adobeforums.com]

The best solution I've come up with is this:

1. Create a 2x2 image in white.
2. Then take the pencil tool and put a black square in the upper left and lower right to create a checker pattern.
3. Save it as Checkers.psd
4. Go to Edit > Define Pattern... and set Checkers.psd as a new pattern
5. Create a layer on top of the gradient you're working on and paint it with this pattern.
6. Set this new layer's blending mode to "Overlay"
7. Set the opacity to taste (40% looks pretty good to me).

[Steve_...@adobeforums.com]

So I used my method above for the green background gradient on my website...
<http://www.bucketsoft.com/>

The background is just a 2 pixel wide strip that's repeated. It looks pretty smooth on my monitor.

[christoph_pf...@adobeforums.com]

Paul, have You checked Dither for the Gradient Tool and tried adding a little noise with the Add Noise-Filter?

[Mark_R...@adobeforums.com]

Christoph is right. The best method is a combination of Add Noise and Steves method. The advantage with noise - its random and not a 2 pixel check pattern. The 2 pixel check pattern will only work with low res images.

These are the best methods to non-destructively apply the necessary noise to a gradient.

• 1 - apply a pattern overlay layer style. First you generate a noise pattern (6 or 4% monochromatic noise applied to a neutral 128,128,128 grey ) and blur this noise by a tiny amount 1 or 2 pixels. Then make a seemless pattern from this about 200 pixels square. Then go to the pattern overlay layer style. Blend the pattern using Overlay or Soft Light at 70% opacity.

• 2 - make a new layer. Fill with the pattern generated above or just fill the layer with gray and noise/blur it. Blend 70% using Soft Light or Overlay