is there a feature to add user ids (view only) instead of admin ids? I created a user id from the admin information section (by checking just "view all albums". but it does not work. Pls suggest.

There is only one kind of user in zenphoto. But each user may be assigned rights as you see fit. So you can create a user with only view rights.

What do you mean by "it does not work?" It certainly works for me.