I want access to the original image is not possible. If you go through the slideshow, you can double-click on the image and you come to a single image page. I do not want this.

what can i do?

Sorry for my english

Not sure what you mean about double clicks. Those are nowhere used. But what slideshow mode? Colorbox or jQuery? Colorbox mode has a plugin option to change the image type to either full image or image page. But in any case the actual full image is outside Zenphoto's management.

Please read here, too:
http://www.zenphoto.org/news/an-overview-of-zenphoto-users#rules-of-protection-andvisibility-for-zenphoto-obj

I want that you can not on this link to get to the detail image. http://www.rene-rohr-foto.ch/galerie/albums/Sport-Veranstaltungen/Eisklettern-Pontresina-2014/Eisklettern_2-1-von-1-.jpg

You did not answer what slideshow mode you are using and I don't see any on the site active.

You can enable Options > Full image protection.
But this will not prevent anyone from guessing the full url. You would have to protect that server side as it is outside of Zenphoto: https://github.com/zenphoto/Unsupported/blob/master/misc/htaccess-against-hotlinking/htaccess.txt