Diffusing light for softer shadows like in real life

This post might a bit premature, I’ve looked at a few tutorials about lights in blender, but if I missed something maybe someone can direct me to some information like tutorials, posts, etc. related to this?

I am very new Blender as well as 3d in general. I come from photography and moviemaking and let’s just say I’m having a lot of trouble understanding how to light a scene. I don’t understand half of what I’m doing technicaly when I’m lighting a scene for a movie, but I always get what I want by adjusting the lights intensity, diffusing them, adjusting camera settings like whitebalance and f/stops so I don’t really mind about measures like watts. As long as I can understand what is happening physicly in the picture I get from it. So playing with numbers is fine by me, only have to learn and adapt. It’s how to manipulate light that is confusing me. For example, in real life sometimes I only need to have one spot to light a scene by pointing at a wall, using it to diffuse the light so shadows are softer and not as sharp as if I pointed it directly on the subject. All that’s left to do is add some focused/smaller lights on objects or person to cut them out depending on the effect I want and where I want to direct the eyes.

I tried many things but I cant seem to find a way to do that. Let’s say, I would like to put a “plane” (in blender) between a light source and the subject, the same way I would do in real life with a gel/filter in front of a spot. But even if I set a transparency on the plane’s material, yes I can see thru it, but either light is completely blocked or doesnt diffuse the light to make softer shadows to objects on the other side. The light only gets weaker. I tried playing with emit and other settings. Shadows are always very sharp no matter what.

Is it the same thing in any 3d app? Any way simulate something like this?

And sorry if my english is bad.

http://blenderartists.org/forum/showthread.php?p=753636#post753636

Have you seen this vid from the '06 Blender Conference? They go through quite a few lighting/shadow techniques and settings for use in the Blender renderer.
http://video.google.com/videoplay?docid=-5167385886400683169&hl=en

Some starters:

http://mediawiki.blender.org/index.php/Manual/Lighting

http://blender.active-domains.com/c3688.html

SHADOWS:
http://download.blender.org/documentation/htmlI/ch12s04.html