Im a new ZenPhoto User and have one Question.

Is there any chance that i can Give an User the Rights that he only can see Public and his Own Images?

Please read here: http://www.zenphoto.org/news/an-overview-of-zenphoto-users

I Read this. But my question is. Is it possible to show / block any Image for any User?

As you read you can only assign user rights to top level albums, so no. But you can password protect albums directly.

I write again because i hope you missunderstand me.

I want as an example an subfolder with 3 Pictures

and i have 3 Users

There is no chance that i can Configure that User 1 sees pic 1 user 2 Pic 2 and user 3 pic 3.

I thought i realize that with the owner field?
user 1 is owner of pic 1 ?!? etc.

No, there is no configuration for that because as said you can only assign rights to top level albums (why is explained on the article).

If you need to sort out that by owner you have to code that on your theme. But of course leaving out images will confuse pagination.

Is there a mini tip for me in which file i must look to code it in?

Well, all where images are. Best you read the theming tutorial.