Digital artist Calvin Hollywood has been experimenting with two of the more obscure new features in Photoshop CS5, the Subtract and Divide blending modes. Here he shows how to use them to produce a pair of creative effects:
Digital artist Calvin Hollywood has been experimenting with two of the more obscure new features in Photoshop CS5, the Subtract and Divide blending modes. Here he shows how to use them to produce a pair of creative effects:
I think the original idea of these modes is to create a gray Layer above your target Layer, and then switch to either Subtract, or Divide, and adjust the Opacity.
Also, the Subtract mode is a better alternative to the Difference mode.
I frequently use the “Divide” blend mode in CS4. You get the same results by inverting a layer and use the Color Dodge blend mode. I use it to compare an image to another with an element removed. It is useful for extraction/masking. I’ll have to put up a tutorial one of these days.
The subtract blend mode is an inverted Linear Burn.
Interesting! I take back any comments I may have made questioning the merits of these modes.
As you said though, they are kept pretty hush-hush, considering they’re part of one of PS’s most important features. Is there a particular reason why?
[It’s just a matter of having the nice problem of too many features to talk about quickly/easily! There’s plenty I still haven’t discussed here. –J.]
Somewhat underwhelming video – any of you have any concrete uses for these new blend modes?
The divide and subtract blend modes are mostly intended for calibrated imaging (microscopy, astronomy, etc.). You can also use them for HDR toning tricks (or experimentation).
And they complete the basic math set needed for some advanced compositing.
Creative uses: those are just bonuses.
Hi all
That you John for posting this video.
@All
I will show more tutorials about the new blendmodes soon.
There are much more stuff what you can do with them.
lg Calvin
3D compositors using Photoshop may find the divide blend mode useful for turning pre-multiplied rgb cg images into unpremultiplied ones by dividing the rgb of the image by the alpha. More here:
http://www.digitalartform.com/archives/2010/05/photoshop_ps5_d.html
While true that you can use divide to remove premultiplied opacity… that shouldn’t be necessary in Photoshop because Photoshop is always using straight/unmultiplied color.
And the example shown in that URL should composite correctly without the divide, unless it was exported to some other application that incorrectly assumed premultiplied color in an unmultiplied file format.
Yes, the layer order in Photoshop is “divide by this” and “subtract this” – otherwise several calculation pipelines would be difficult to impossible to achieve.
Why does he duplicate the layer – would not a blank Adjustment Layer do as well?
Sorry, what a stupid question of me.
I had watched the movie inattentively …
It actually made the buildings look more 3d and pop in only a few simple moves I like it.
It shouldn’t be necessary in Photoshop, but I work in a wider world than that and Photoshop is a tool within a wider context.
What if I want to ‘unpremultiply’ some images to be used as textures and transparency maps on cards in Maya? Now it’s easier for me to use Photoshop to accomplish that without having to settle for gray matte lines around the sprite edge.
…and I believe Photoshop has always had a ‘divide’ blend mode. It involved faking out ‘Linear burn,’ or something like that.