Slide transition speed in impress.js

One of ATOR's purposes is to serve as some kind of reminder for all the tricks and actions we find out during our hacking sessions.

Today I'm preparing a presentation  with impress.js.

After my last lecture a listener told me that the transition speed between the single slides of my presentation was to fast.
I was moving across aerial photos, zooming in and out on points of interest.

After some groping in the dark I found the solution on github.

It's very easy:

Look for your impress.js file, open it with an editor and look for the tag "transitionDuration".
You will find it among the defauld config values, it's expressed in milliseconds. 6000 means 6 seconds of transition time.

Consider that this option defines an equal transition time for the whole presentation.
It's also possible to set different speed for every single slide transition.