Use custom image size instead of "full" size

Hi, I’m interested in finding out the solution to this as well. I’ve tried the above using 100 in the filter but that didn’t work.

Does anyone else have any ideas – it does seem strange to load the full-size image rather than large as clients are often unaware of the importance of file size.

This is the code I’ve used

function oikos_get_attachment_link_filter( $content, $post_id, $size, $permalink ) {

    // Only do this if we're getting the file URL
    if (! $permalink) {
        // This returns an array of (url, width, height)
        $image = wp_get_attachment_image_src( $post_id, 'large' );
        $new_content = preg_replace('/href=\'(.*?)\'/', 'href=\'' . $image[0] . '\'', $content );
        return $new_content;
    } else {
        return $content;
    }
}

add_filter('wp_get_attachment_link', 'oikos_get_attachment_link_filter', 100, 4);