Make a drop shadow with layer styles, then go Layer>Layer Style>Create Layer. This will create an independent layer of that shadow. Now you can stretch distort and transform it, (Edit>Transform>Distort) selectively blur it, whatever you want.
Or don’t even bother with a drop shadow to start with.
Envision what the shadow’s basic shape should look like and make a lasso selection, fill with black on an underlying layer, then apply gaussian blur and adjust opacity to suit. For added realism add more layers in the same fashion, closer to the object/floor interface where the shadow would be the darkest.
Or, use good, old-fashion drawing skills and render a shadow with the Airbrush.
Carl.
John-
In making your own shadow layer – Do you have to set the blend mode to Multiply for most realistic interaction with background? Or does it really matter?
cb
Normally you’d wany multiply or darken, whatever seems to give the best appearance for your particular photo.
Depending on lighting conditions that you’re trying to duplicate you might also want to add a gradient mask over the shadow so it appears to grow less dark as it gets further from the object. Selectively blur the mask as it gets further away, too.
If you’re trying to cast a shadow into a photo, don’t use gray for the shadow color, but use the eyedrop tool to pick a color which is the actual color of the shadows you’re trying to match in your image. If it’s an artifical light situation there may even be two separate, overlapping cast shadows from two separate light sources, each with it’s own color.
If the surface the shadow is cast onto is uneven you’ll need to use the paint and erase brushes to try to match the texture and form of the surface at the shadow’s edge.
It’s an art. Not a keystroke.
