Ok, you need to be using a child theme, then add this to your functions.php file:
/* POST THUMBNAIL
================================================== */
if (!function_exists('sf_post_thumbnail')) {
function sf_post_thumbnail($blog_type = "", $fullwidth = "no") {
global $post, $sf_sidebar_config;
$thumb_width = $thumb_height = $video_height = $gallery_size = $item_figure = '';
if ($blog_type == "mini") {
if ($sf_sidebar_config == "no-sidebars") {
$thumb_width = 446;
$thumb_height = NULL;
$video_height = 335;
} else {
$thumb_width = 370;
$thumb_height = NULL;
$video_height = 260;
}
$gallery_size = 'thumb-image';
} else if ($blog_type == "masonry") {
if ($sf_sidebar_config == "both-sidebars" || $fullwidth == "yes") {
$item_class = "col-sm-3";
} else {
$item_class = "col-sm-4";
}
$thumb_width = 480;
$thumb_height = NULL;
$video_height = 360;
$gallery_size = 'thumb-image';
} else {
$thumb_width = 970;
$thumb_height = NULL;
$video_height = 728;
$gallery_size = 'blog-image';
}
And change the bottom ‘970’ width
– Kyle
.