@ rskrodzki > If there's no function.php file at the root of your theme directory, just create it and paste Otto42's code inside (where XXX is your max width images value) :
<?php
$GLOBALS['content_width'] = XXX;
?>@ furiousphotographers > A trick could be to give an extra-large value in your theme function file, 9000 for example, then all images smaller than 9000 pixels will be inserted with their real max values when "full-size" option selected.
