Blending Modes

Understanding blending modes, is an essential part of deriving the most from any photo processing package

Applying an analogy with analogue film and darkroom days, blend modes are tools and methods that the dark room technician would have used to

apply local exposure variation (as in dodging and burning);
insert new components of an image;
create new images from combinations;
modify colour locally and globally across an image;
add and imply texture.

In the darkroom blending of images is achieved by

making copies or negatives or derivatives of the components of the final image;
making masks from the components or combination of the components;
changing the properties of layers, such as contrast, hue, saturation etc;
printing these components separately onto the final print or yet another intermediate negative;
binding the intermediates together and printing through the bound bundle.

Does this sound familiar? If you are reasonably up-to-speed with the techniques in Paint Shop Pro, then you’ve already done the basics. Blending modes will let you take these skills to the next level.

On this site, there are loads of tutorials with examples to steer you towards the techniques or to refresh your memory – yes even I have to check on occasions.

How does it work? Simply, the answer is, “Paint Shop Pro looks at the numerical value of the stack of pixels in the layers that you’ve assembled and applies a simple arithmetical procedure to them.”

If you know the procedure, then you can make a rough guess as to the output you might get. Just like the darkroom days, you won’t always get what you thought you’d get. Unlike the darkroom days you won’t have to waste time, money and materials whilst you make another set of film layers – you just click the mouse a couple of times! Experimentation is the key to success with the blending modes.

The ideas and images in this tutorial were inspired by the work of Odette England who went to photograph the Australian Outback as a visiting fellow of the University of New South Wales

Her project (AsAboveSoBelow) was about the attachment indigenous people have for their landscape and environment. The Aborigines consider themselves as one with the landscape - the sky above, the earth below and they themselves acting as a middle layer.

Her approach was to shoot the ground beneath her feet and then the sky directly above that spot, to give a visual, photographic representation to this feeling, which is alien to white Australians and Europeans in general.

Blending Modes Examples

My images to illustrate the principles of blending modes, were a field of dandelions (taraxacum officinale) and the sky directly above.

This image is the field of dandelions in full flower ...

And this image is the sky directly above

The extent to which the modification occurs in the lower layer, depends on the blending modes chosen and the amount of blend or opacity set in the upper layer.

Effects of Different Blending Modes on two different images ...

	Normal Top layer only visible unless the opacity is reduced
	Darken The darker part of the image pair masks the lighter part of the lower of the image pair. So, a black item totally masks the lower layer and is seen as black; white items allow the lower layer to be seen; grey items are seen but allow the lower layer to be seen through them.
	Lighten The lighter part of the image pair masks the lighter part of the lower of the image pair. So, a white item totally masks the lower layer and is seen as white; black items allow the lower layer to be seen; grey items are seen but allow the lower layer to be seen through them.
	Hue The hue (“colour” eg blue) of the upper layer is applied to the lower layers; the colour is therefore adjusted as a result of the addition.
	Hue (Legacy) The hue of the upper layer is applied to the lower layers; the colour is therefore adjusted as a result of the addition. (compatibility with earlier programme versions)
	Saturation The saturation (or “chroma” “brightness” ie more saturated = further from grey so not muted) - of the upper layer is used to modify the saturation of the lower layers.
	Saturation (Legacy) The saturation of the upper layer is used to modify the saturation of the lower layers. (compatibility with earlier programme versions).
	Colour The hue and saturation of the upper layer modify the lower layers.
	Colour (legacy) The hue and saturation of the upper layer modify the lower layers. (compatibility with earlier programme versions).
	Luminance The luminance or lightness of the upper layer is added to the lower layers.
	Luminance (Legacy) The luminance or lightness of the upper layer is added to the lower layers. (compatibility with earlier programme versions).
	Multiply The shadows area intensities are multiplied together so that the luminance values are decreased but not arithmetically. So black items produce a black result in the lower layer; white items have no effect on the lower layer; grey items darken the lower layer. For another tutorial on this blend see this link.
	Screen The numerical values of the two layers are added together, effectively lightening. The numerical values for the densities are arithmetically added together; the overall image is lighter; in the highlights there is a tail off since the total value cannot exceed 255. The effect on the lower layer is just like using a “screen”, in that, where there are black or grey items in the upper layer, they act as holes through which the lower layer can be seen; white acts as a mask through which nothing can be seen. For another tutorial on this blend follow this link.
	Dissolve Replaces some of the selected layer randomly with the underlying layer. The amount of opacity in the upper layer determines the amount of random viewing of the lower layer. It acts like a sort of fuzzy “screen”.
	Overlay The images are directly added over one another; so that anything below the mid-grey point becomes darker and anything above the mid-grey point becomes lighter. This is a combination of multiply and screen. The effect is to blend the two layers into each other to produce an image with a reasonable range of tones. For another tutorial on this blend see this link.
	Hard Light The images are directly added over one another; so that anything below the mid-grey point becomes darker and anything above the mid-grey point becomes lighter; increases contrast. A combination of multiply and screen.
	Soft Light The images are directly added over one another; so that anything below the mid-grey point becomes darker and anything above the mid-grey point becomes lighter; decreases contrast. A combination of burn and dodge. For another tutorial on this blend see the Dodge and Burn Tutorial.
	Difference A straightforward piece of arithmetic is carried out; the difference between the intensities is calculated; ie two intense shadows become black; two intense highlights become black; two mid-tones become black; a shadow plus a highlight becomes mid-grey.
	Dodge The value in the upper layer decides the output; as in analogue photography in which the light is held back from the print, the greater the whiteness of the upper layer the more the density of the bottom layer is reduced and the lighter it becomes. For another tutorial on this blend follow this link.
	Burn The value in the upper layer decides the output; as in analogue photography in which more light is added to the print, the greater the black tone of the upper layer the more the density of the bottom layer is increased and the darker it becomes. For another tutorial on this blend follow this link.
	Exclusion A straightforward piece of arithmetic is carried out; the difference between the intensities is calculated; ie two intense shadows become black; two intense highlights become black; two mid-tones become black; a shadow plus a highlight becomes mid-grey; a softer result than difference.