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Layer Blending Notes

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      Layer Mask
Layer Mask Often created from a selection, a layer mask determines what parts of a layer are visible.  
Vector Mask Often created from a path, a vector mask determines what parts of a layer are visible.  
 

 

 

   
Opacity

On the layers palette. A slider from 0% - 100%

Opacity determines how opaque the layer is. It affects the contents of the layer and the layer styles equally.

  Opacity & FIll Opacity
Fill Opacity

On the layers palette. A slider from 0% - 100%.

Fill determines how opaque the contents of the layer are. Fill Opacity affects only the contents of the layer, any layer styles are fully visible.

 
 

 

 

Blend If
Bland If
 

 

 
This Layer

Drops out the darkest and/or lightest pixels.
Any pixel with a brightness value less than the left slider is made transparent allowing the layer below to show through.

Any pixel with a brightness value greater than the right slider is made transparent allowing the layer below to show through.

Pressing the Alt key allows you to break the slider in half, use this to fade in the effect.

Splitting Blend If Sliders
Underlying Layer

Drops out the pixels over the darkest and/or lightest pixels in the layer below.
Transparency is determined by the brightness of the pixel on the level below.

If the pixel below has a brightness value less than the left slider, the pixel in the current layer is made transparent allowing the layer below to show through.

If the pixel below has a brightness value greater than the right slider, the pixel in the current layer is made transparent allowing the layer below to show through.

Pressing the Alt key allows you to break the slider in half, use this to fade in the effect.

 

 

 

Layer Blending Modes

Determine how the pixels in the current layer interact with the pixel in the layer below, actually the sum of all the layers below.

The horizontal separators, create groups of similar modes. Most of the times this similarity is visual, but in some cases it is purely mathematical.

Layer Blending Modes
Normal

The pixel in the upper layer cover the pixel in the layer below,
Dissolve

Makes random pixels on the upper layer go transparent to reveal the layer(s) below.

If the more transparent the pixels on the upper are to start with, the faster they will go transparent (dissolve).

Disolve Blending Mode
Darken

Photoshop compares the brightness of the pixel on the upper and lower layers. The result is the darker color.

It doesn't matter which is the upper of lower layer.

Darken Layer Blend
Multiply

The numeric brightness of the upper layer is multiplied by the the brightness of the layer below. The result;t is then divided by 256 (the total number of brightness levels)

((Mid-grey:128) x (Mid Grey:128)) / 256
= 64

This always darkens the lower image.

This appears to be done on a per channel basis.

Multiply
Color Burn

Wherever the upper level is darker than the lower level, the brightness and saturation of the upper level is applied to the lower level.

The effect will be different depending on which is the upper and lower layer.

Color Burn
Linear Burn    
Lighten The opposite of Darken.

Photoshop compares the brightness of the pixel on the upper and lower layers. The result is the lighter color.

It doesn't matter which is the upper of lower layer.

Lighten
Screen

If a pixel of the upper layer is brighter than the pixel of the lower layer, the upper layer brightness will be used.

Because this is done per channel, the hue may also be affected.

It doesn't matter which is the upper of lower layer.

Screen
Color Dodge

Wherever the upper level is lighter than the lower level, the brightness and saturation of the upper level is applied to the lower level.

The effect will be different depending on which is the upper and lower layer.

Color Dodge
Linear Dodge    
Overlay

Areas of the upper layer that are above the 50% brightness level are screened and those that are below 50% brightness are multiplied.

The effect will be different depending on which is the upper and lower layer

Very useful for dodging and burning.

Overlay
Soft Light

Similar to Overlay, but the effect is more muted.

The effect will be different depending on which is the upper and lower layer

Very useful for dodging and burning.

Soft Light
Hard Light

Similar to Overlay, but harsher.

The effect will be different depending on which is the upper and lower layer

Hard Light
Vivid Light    
Linear Light    
Pin Light    
Difference

The two layers are compared. The more different they hue and brightness are the brighter the resulting pixel will be the more similar they are the darker the pixel will be.

Used mainly when something is too big to scan and multiple scans are made. You can use this blending more temporarily to line up the scans.

It doesn't matter which is the upper of lower layer.

Difference
Exclusion    
     
     
Copyright 2005 Laura Balsam