Es gibt in zahlreichen Foren noch zahlreichere Vorschläge und Plugins die empfohlen werden. Die meisten dieser Lösungen funktioniert nicht, oder nur mit Tricks für eine ganz  bestimmte Version von WordPress bzw. der NextGen Gallery.

Hier meine Lösung:

(Getestet mit WordPress 3.0.4 und NextGen Gallery 1.7.2)

Schritt 1:

Plugin: WP Slimbox2 (http://wordpress.org/extend/plugins/wp-slimbox2/)

Das Plugin installieren, aktivieren und die Konfiguration auf den Standardeinstellungen belassen.

Schritt 2:

Unter “Galerie” –> “Optionen” –> “Effekte” die Einstellung “Lightbox” auswählen

Der Code muss wie folgt aussehen:

rel=”lightbox[%GALLERY_NAME%]“

Fertig!

Nun werden alle Bilder aus der Galerie in einer Lightbox geöffnet.

PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 6233929 bytes) in …

The exception happens when the thumbnails are created. Creating the thumbnails seems to be a memory exhausting hob. I searched the web and found a few solutions that looked promising like this one

remove the comments from
//@ini_set(‘memory_limit’, ’128M’ from the file “gd.thumbnail.inc.php”

but that did not help, because most hosters do not allow you to increase you memory_limit. I found lots of comments on the web that reported the malfunction of the above bugfix (workaround).

Alex Rabe the developer of nextgen comments on the problem:

The reason is the increased memory needs for WordPress itself, a developer noticed that they raised the requirement up to 256MB !

(http://alexrabe.de/2010/07/05/wordpress-3-0-memory-requirements-256-mb/)

The only solution that worked for me was to downgrade the php version i am using on my webspace. All the versions above 5.x did produce the “memory size exhausted” exception.

I downgraded to version 4.4.x and everything was fine again. I tested the procedure with an almost 200 images .zip file. Everything worked fine!

I did not discover any problems despite the message “some features of nextgen require php 5.2.x” netgen displays on the plugin dashboard.

Maybe someone can comment on the limitations with php version 4.4.x in nextgen gallery.