Rollover thumbnails

Gena supports the "rollover" effect for thumbnails. We call it rollover thumbnails.
Rollover is an image that changes when the mouse pointer moves across it. When the user points to one of the thumbnails an Internet browser displays another version of the same thumbnail. The Thumbnails window allows you to create rollover by adding special effects to a thumbnail picture (e.g. modifies brightness, color or border color).

Here is an example of rollover thumbnails. Move the mouse pointer to any thumbnail below and see for yourself:

In this example we used two effects: a different border color and a monochrome image.

There are two drawbacks of rollover thumbnails: user's browser should support Javascript to display them and it requires two sets of thumbnail images increasing the "gallery weight" (total size of gallery files). However, we don't think these drawbacks are serious. First, every modern browser supports Javascript and it's usually enabled (you've probably seen a lot of pop up adds lately, haven't you? So it's time to use Javascript for noble purposes!) Second, thumbnail files usually take up a very small amount of the disk space anyway compared to full-size images, so a typical gallery size increase will be less than 5%. We think you can afford it.
Of course, you can always disable rollover thumbnails, in which case Gena will create only one set of thumbnails and no Javascript code - we promise!