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