Slideshow of images which are not a field of node
I have solved the problem by using Lightbox2 module, which allows to render a Slideshow with no need of a View or configuring the images as fields of nodes.

You can see the solution with some code, in this other question and answer of mine. So this is a solution for someone looking for:


A gallery of many many images.
Slideshow with thumbnail.
Thumbnail + Medium image (detail of product, for example), with the Slideshow launched from the Medium image, no the thumbnails.


How to configure a Slideshow with thumbnails in modal window