Creating Shadows in Adobe Photoshop

Creating major shadows

The usual reason for wishing to add this sort of shadow is that you have added an object into a scene and wish to make it blend more realistically into its surroundings.

In order to enhance realism you must remember that there are three main things that affect major shadows:

• The direction of the lighting.
• The shape of the object casting the shadow.
• The distance of a given point within the shadow from the object.

To use with this tutorial i knocked up this (757Kb psd) quick composite of a baby and some rushes.

The main image was chosen because it is strongly backlit and is a high quality jpg; the baby was chosen for no obvious reason.

Step 1 - Ascertain the direction of illumination.

Basically i mean find out where the light is coming from. Do this by connecting an object in the image with it's shadow. Here you can see that the light is coming from above and slightly to the left. This will result in a shadow on the decking going from upper left to lower right.

Step 2 - Create an initial shadow.

Create a new layer and name it shadow. Ctrl-click the baby layer to select by alpha and then in the new layer fill this shape with a dark grey colour.

Use the Flip vertical command (edit/ transform/ flip vertical) to up-end this selection.

Mask out the lower legs of the shadow roughly so that the shadow matches the curve of the walkway.

Step 3 - Tranformations.

*This is the hardest stage to get right and the only way to get really good effects is to spend a good deal of time on it*

Use the transform tools (edit/ transform) to adjust the shape of the shadow so that it looks as though it is projected onto the walkway. It took me about 30 mins of fiddling until i felt reasonably satisfied with my results at this stage.

Remember to compare the shadow with real life, move your desklight around and use your hand as a model to guide you if nessecary. Also remember the direction of the light which we found in stage 1.

once you have done this you can more accurately mask out the shadow so that it matches the curve of the walkway.

Step 4 - Blending it all in.

This is the stage where you bring it all together, good blending will turn that block of colour into a realistic looking shadow.

Set the layer blend mode of the shadow layer to "Hard Light".

Apply the "Radial blur" filter to the shadow layer, set to spin, amount 10, with the centre at the point where the shadow meets the edge of the walkway. This will simulate the way a shadow becomes less defined as it moves away from the object which casts it.

Now apply a 4 pixel gaussian blur to the shadow layer to make the edges smoother, you may have to re-adjust the mask on the shadow around where it meets the edge of the walkway.

Right click on the mask for the shadow layer and select "apply mask". Now add a new mask to this layer and drag a white to black gradient from the edge of the shadow nearest the baby to slightly beyond the point furthest away from it. This will simulate the way a shadow becomes less intense as it moves away from the object which cast it.

Finally, create two duplicates of the shadow layer and name them shadow burn and shadow multiply. Set their blend modes to color burn and multiply respectively and then adjust their opacity until you are happy with the look of the shadow.

Finished

If you followed all that you should end up with an image which is somewhat better than mine (797Kb psd) as this was fairly hastily done.

I also added an adjustment layer, masked to the baby, which adjusts the hue/saturation to match better with the picture.

Any advice on this would be gratefully received, any questions likewise. E-mail me.