AKA. A quick lesson in Photoshop Layers J
MattMatic, 21st June 2004
Open up the “baby.psd” (880k) file into Photoshop. You will see there are now a total of five layers. I’ve tried to show a good range of layers manipulations, just to get you started thinking in PS layers!
Let me explain each layer, from the bottom up. Make sure you have the Layers Palette visible (the F7 key toggles the palette’s visibility).
This is, as its title says, the original image. Resist the urge to make modification to this layer! When harnessing the power of layers, it’s always best to leave a completely unedited version of the image.
To sort out the overblown highlights on the forehead, I created a new layer and named it “Forehead”. Then used the Clone tool to clone some of the cheek (with “Use All Layers” checked). To blend in the edges, I used the healing brush (again with “Use All Layers” checked). This gave a separate layer with the forehead fill-in.
However, the overall effect was too flat, so the layer’s opacity has been reduced to 60% (see the top right of the layers palette). This tells Photoshop to make the layer, in this case the forehead, slightly transparent.
Changing the layer opacity is a great way to regulate the amount of an effect or adjustment.
To enhance the eyes alone, I selected the eyes with the lasso tool and copied them onto a new layer. (TIP: With the selection enabled, press Ctrl-J to copy and paste onto a new layer in one go! If you have nothing selected, Ctrl-J will copy the whole layer.)
With the eyes layer selected, I ran an unsharp mask filter.
To blend the edges in, rather than erasing parts of this eyes layer, I added a layer mask. The mask dictates what should show, and what should be hidden. Use the menu “Layer / Add Layer Mask / Reveal All”, or press the second icon from the left at the bottom of the layers palette (a grey rectangle with white circle).
Make sure the mask is selected – click on the new white block to the right of the eyes in the palette. A second rectangle should appear around the mask to indicate it’s selected.
Now pick a soft black brush. Reduce the opacity of the brush to about 30% so you can build up the mask. Now paint – wherever you paint black the layer is hidden, wherever you paint white the layer shows through. Obviously, grey shows a percentage.
You should be able to see the soft grey edges to the eyes in the mask that blend in the sharpening effect.
TIP: To see the difference between normal eyes, and “sharp eyes”, press the little eye icon for the layer.
TIP: To temporarily disable a layer mask, hold the Shift key and click the layer mask. A red cross appears on the layer mask. Shift-click to re-enable.
TIP: To edit just the layer mask, Alt-click the layer mask. In this mode you can apply filters, and copy-and-paste the mask. So you can do a rough mask with a hard brush, Alt-click on the mask and run a Gaussian blur to soften it.
Here is some wonderful Photoshop trickery…
Add a new blank layer. Now change the blend mode from “Normal” to “Overlay” – this can be changed at the top of the layers palette. Overlay does this: wherever the layer has 50% grey it does nothing; wherever the layer has white the underlying image is lightened; and wherever the layer has black the underlying image is darkened.
I changed the layer’s opacity to 50% so we don’t lighten and darken too heavily. Now pick a large soft white brush with a very low opacity (about 10 – 20%) and paint round the iris and eyes. This brings out the eyes.
Now toggle to a black brush and darken the edges to produce some depth.
TIP: Press “D” to set the default white/black colours, and “X” to quickly toggle between the foreground and background colours.
This layer is an adjustment layer. To add one of these, use the menu: “Layer / Add Adjustment Layer” and pick one of the regular sets. Alternatively, click on the icon at the bottom of the layers palette – a circle with half white, half black – and select from the fly-out menu.
The layer mask is automatically added.
In this case a curves adjustment layer was added with a sharp brighten to create a high-key effect.
To restrict to just the background, pick a soft black brush and paint over the baby – this stops the effect modifying the main image. If you paint into the background area, just switch to a white brush and paint back.
TIP: To adjust the size of the brush as you paint, use the “[“ and “]” keys.
You can see the effect of the layer mask by shift-clicking the mask.
The beauty of adjustment layers is that you can just double click the adjustment (in the layers palette, the box to the left of the chain and mask). You can tweak the curves to your heart’s content.
TIP: To change the degree of the applied effect, reduce the layer’s opacity.
Colour is great for putting colour back into old monochrome images. It will apply only the colour channel of the layer, leaving the luminosity of the underlying image.
Try adding a new layer set to Color blend mode. Pick a red brush and paint. You will effectively colourise the underlying image.
This tells Photoshop to only adjust the brightness, and to leave the colour alone. Have you noticed when you apply a heavy levels or curves that the colours sometimes go wild? Well, add the levels or curves as an adjustment layer and set the blend mode to “Luminosity” – you’ll be surprised at the difference!
We’ve covered overlay for dodge/burn.
However, if you have a colour image and want some extra “punch”, just duplicate the image (completely) onto a new layer and set the blend mode to overlay. Wham!
The associated modes Soft Light, Hard Light, Hard Light, Vivid Light, Pin Light, and Hard Mix all do a similar thing but in slightly different ways. If Overlay is too “hard”, try “Soft Light”. In fact, just experiment.
Hopefully this will give some insight on how to effectively use layers in Photoshop. Some great sources of reference include: www.russellbrown.com, www.hiddenelements.com, and www.digitalretouch.org – and the corresponding books are an excellent source. “Restoration and Retouching for Photoshop” by Katrin Eismann has a superb description of each of the layer modes and some wonderfully practical examples.