I would like to have the photos bigger but without having to click on them as this way seems to take up the whole screen and you need to move your mouse right to left and up and down to see the photo.
You might want to look for a plugin that manages image display.
One that come to mind is: http://forum.coppermine-gallery.net/index.php/topic,57424.msg281323.html#msg281323
But there are others as well.
Examine the documentation for installing and using plugins:
http://documentation.coppermine-gallery.net/en/plugins.htm#plugin
Thank you that is way better now.