Su-57 with external targeting pod - http://alert5.com/2018/08/20/su-57-with-external-targeting-pod/ …. Source: alert5
101KS-N navigation and targeting pod
101KS-P (flight external module) - a high-resolution thermal imager, provides low-altitude piloting and landing in night conditions. It is installed on the compartments of short-range missiles.
101KS-N (ground external module) is a multi-channel optical sighting system of a hanging type, designed to detect and identify ground targets and to ensure the use of aircraft impact weapons (TSA) for them. Source: vpk.name
Sukhoi Pak Fa T-50 (Su-57): Details