Special Effects are not hard, just time-consuming, me and my friends a couple years ago made a star wars fan film. It was around 35 min. It had 12 min of special effects. I was the special effects man, i used photoshop and imovie to do all the special effects: get this:
30 Frames/Sec
12 Min=720 sec
720sec * 30 frames/sec
=21600 frames, thats exporting each frame into photoshop and putting a effect on each frame, took me 2 months