A couple of years ago, i figured out how to change the attachment page image size by editing a core wordpress file. This gets overwritten every time WordPress is updated which is not efficient at all. I’m using Genesis Theme Framwork for most of my websites, so here’s a quick fix that can be applied to the Genesis child theme.
Locate the functions.php page in the child theme, and add this chunk of code:
[code]
/*Change attachment page image size*/
add_filter('prepend_attachment', 'ag_prepend_attachment');
function ag_prepend_attachment($p) {
return '<p>'.wp_get_attachment_link(0, 'full', false).'</p>';
}
[/code]
Now the image should be full size instead of the default “medium” size.
I used this
add_filter('prepend_attachment', 'ag_prepend_attachment');
function ag_prepend_attachment($p) {
return ''.wp_get_attachment_link(0, 'large', false).'';
}
wordpress striped the p tags out