Special effects are divided into the categories of optical effects and mechanical effects.
Years ago, people were really impressive for the special effects in some films because the cinematographs used to use mechanical effects. Now, there are many films (usually blockbusters, films with a very big production budget) that use the special effects because are more comfortable. But there is the problem, optical effects are very expensive.

What do you think that is more suitable? Optical effects or mechanical effects?
I think that the best is use a mixture of optical and mechanical effects. The results are more realistic. I have just seen “Hellboy” and I like the use of this mixture, is really awesome.
Hi, David. I like your information, it´s very good, and the photo shows perfectly the change over
time of film and special effects.
For me, mechanical effects have more merit than virtual effects. Virtual effects are “better”, but mechanical effects have more work to do it.