Normal Blending Modes:
Blending modes in the Normal Blending Mode family all exclusively use the opacity of the layers to control the blending between the layers. No external algorithm is used to blend the individual pixels.
Normal
The Normal blending mode is the default blend for all images in Photoshop. In this mode, there is no true blending being performed, although you can use the opacity slider to reveal additional layers.
Dissolve
The Dissolve blending mode blends the layers in Photoshop by using a dither pattern (noise/static). The intensity of this dither pattern is determined by the opacity of the layers being blended.
Darken Blending Modes:
Blending modes in the Darken Blending Mode operate by darkening the colors in the layer being blended. Any white in the layer will become transparent and any other colors will have some associated darkening affect on the layer it is being blended into.
Darken
Darken utilized the luminance values in the RGB channels in Photoshop between the base layer and the layer being blended and selects the darker of the two to display.
Multiply
Instead of comparing the darkness of the layers, multiply instead takes the luminance values in the RBG channels between the base layer and the layer being blended and multiplies them together resulting in a darker image.
Color Burn
Color Burn darkens the image by increasing the contrast between the base layer and the layer being blended in order to saturate the mid-tones and reduce any highlights in the image.
Linear Burn
Linear Burn darkens the image by decreasing the brightness of the base layer based upon the color values associated with the layer being blended in the image.
Darker Color
Darker Color is very similar to Darken, except that instead of looking at the RBG channels individually, Darker Color looks at the channels together and selects the darkest combination for the image.
Lighten Blending Modes:
Blending modes in the Lighten Blending Mode operate by lightening the colors in the layer being blended. Any black in the layer will become transparent and any other colors will have some associated lightening affect on the layer it is being blended into.
Lighten
Lighten operates by comparing the colors in the base layer and the layer being blended into it and selecting the lightest color between the two. This is essentially the inverse of Darken.
Screen
Screen uses the luminance values of the pixels int he layers and selects the brighter pixels in the image to be displayed.
Color Dodge
Color Dodge decreases the contrast between the base layer and the layer being blended into it which reduces the saturation of the mid-tones and increases the highlights in the image.
Linear Dodge (Add)
Linear Dodge (Add) operates by increasing the brightness in the base layer based upon the associated color values of the layer being blended into it.
Lighter Color
Lighter Color simply compares the the brightness of the base and blending layer and displays the brightest of the two in the image. This blend mode utilizes the RBG channels to accomplish this type of blend.
Contrast Blending Modes:
Blending modes in the Contrast Blending Mode operate by comparing the colors in the layer to 50% gray. Colors that are lighter than 50% gray receive a lightening effect. However, colors that are darker than 50% gray receive a darkening effect in the image.
Overlay
Overlay is essentially a composite blend mode of Screen and Multiply. If the colors in the layer are lighter than 50% gray, then a Screen blend mode is applied at half strength. If the colors in the layer are darker than 50% gray, then a Multiply blend mode is applied at half strength instead.
Soft Light
Soft Light assigns a darkening or lightening effect by comparing the luminance values of the base layer and the layer being blended into it, but in a subtle fashion than other blending modes.
Hard Light
Hard light uses a composite of the Screen and Multiply blend modes similar to Overlay. However, Hard Light utilizes the brightness of the blend layer to perform its blending.
Vivid Light
Vivid Light is a very strict version of Overlay where anything darker than 50% gray is darkened and anything lighter than 50% gray is lightened.
Linear Light
Linear Light is essentially a composite blend mode of Linear Dodge and Linear Burn. If the colors in the layer are lighter than 50% gray, then a Linear Dodge blend mode is applied. If the colors in the layer are darker than 50% gray, then a Linear Burn blend mode is applied instead.
Pin Light
Pin Light completely removes the mid-tones in the image by performing the Darken and Lighten blend modes simultaneously.
Hard Mix
Hard mix blends the layers by adding the values of each RBG channel in the base layer and the blending layer. The only colors that can be present in the image is white, black, red, green, blue, cyan, magenta, or yellow.
Inversion Blending Modes:
Blending modes in the Inversion Blending Mode operate by utilizing variations between the base layer and the blending layer to create the specific blend.
Difference
The Difference blend mode uses the differences between the pixels in the base layer and the blending layer to perform the blend. In this blend, white inverts the pixel color of the base layer, black creates no change, and other colors creating variation in between.
Exclusion
Exclusion operates very similarly to the Difference blend mode with the exception that pixels that are blended with 50% gray will simply remain 50% gray in the image.
Subtract
The Subtract blend modes performs a blend in the image by subtracting the color values of the pixels in the blending layer from the base layer creating a darkening effect in the image. This effect is more pronounced in lighter areas of the image.
Divide
Divide creates an opposite effect to Subtract where darker areas of the image become lighter in the image due to the blending of the color values in the pixels between the base and blending layers.
Component Blending Modes:
Blending modes in the Component Blending Mode operate by utilizing hue, saturation and brightness to create blending effects.
Hue
The Hue blend mode does not affect the luminosity or saturation of the image. This blend mode simply changes the hue of the base layer to match the pixels of the blending layer.
Saturation
The Saturation blending mode does not affect the luminosity or hue of the image. This blend mode only affects the saturation of the base layer by changing it to match the blending layer.
Color
The Color blending mode does not affect the luminosity of the image. This blend mode changes the hue and saturation of the base layer by altering the corresponding values to match the values seen in the pixels of the blending layer.
Luminosity
The luminosity blending mode does not affect the hue or saturation of the image. Instead, this blending mode affects the luminosity of the base layer by altering its values to match the values seen in the pixels of the blending layer.