How to Blur Complimentary Colors WITHOUT Dark Band???

I saw a brief tutorial on a setting in PS that can be changed to alter the way adjacent colors are blurred.

In a nutshell, the tutorial said that PS handles blurring like paint, which creates a dark gray band between the colors. Changing this setting will cause the blurring to behave like light and eliminate the banding.

The problem is, I don't have the slightest idea where I saw it, and Google - usually a friend - is coming up empty.

Anyone know anything about this?

Rad

I thought it was the "Blend colors using gamma" setting in Color Settings, but now I'm not so sure.

Yes, my googling confirms that I was right about that.

But it won't help in this particular example of yours. If you want to choose how your gradient blends, you have to actually choose the middle colour.

Rather than build one gradient, I feel like I have done this with one layer a solid color and the above layer the other color fading to transparent. Not sure what layer blending mode.

What is it exactly that you are trying to accomplish? Changing color blending from additive to subtractive color?

Kirk

I think what you're looking for is a gradient produced in the LAB color space.

Create it on a new layer converted to a smart object.
Open the smart object and convert it to 16 bits/channel if not already.
Then convert to LAB and create the gradient.
Convert back RGB and close the smart object, click save on the exit.

Top half is LAB, bottom is RGB:

What I think you are trying to do will benefit from working in a linear (gamma = 1.0) color model. Try this experiment - take your gradient (cyan to red) and make two documents: 1) sRGB, 2) sRGB gamma 1.0 (linear). You can make a linearized color space using the color settings "Custom RGB" dialog (see screen shot). Use the sRGB color space but change the "Gamma" field to 1.0. For both documents consider using 16bit mode instead of 8bit if you get posterization, etc.

Anyway, in each document lay out your gradient. In the linearized document, perform a "Convert to profile" and select sRGB to bring your linearized gradient into the normal sRGB color space. Then copy and paste that version into your sRGB gradient and compare the two. It will look something like the attached gradients.

kirk

The Custom RGB dialog is accessed as shown in the screen shot below.

kirk

Rad, we REALLY need to know a bit more about your actual task at hand. What are you trying to do - is it a photo, or some kind of other project?

Damo,

The complementary colors was just an example in the tutorial.

The intention was to find a blur method that would most accurately simulate real optical "in the camera" blur of the background of a scene.

Not exactly theoretical, but just gathering "best practice" work-flows for various tasks. I have long been less than satisfied with post processing blur - or bokeh, if you will - but sometimes it is a necessary evil. When I have to do so, I create a depth map ( https://photography-on-the.net/forum/showthre​ad.php?t=102294 ), which is not too bad, but is still clearly in the "uncanny valley."

When I stumbled across the now-forgotten mini tutorial, I thought, "Maybe this will yield better results?"

So, not so much a specific task, but rather, gathering knowledge for future use.

Rad

You may want to work in 32bit mode, where the file will be linear and the effects of light will add physically, whatever the CoC/aperture mask algorithm you implement. After Effects or Blender or similar compositor may give you more flexible tools.

Kirk

https://youtu.be/jCVIq​G-D2Vk

https://youtu.be/QdoV5​is9zMg