Nikon Photomic-Tn is a TTL metering finder designed for Nikon F series cameras. The finder assist in precise and reliable exposure control. The finder has two built-in CdS cells fitted with condenser lenses to avoid back light from entering the eyepiece. The finder allows 100% coverage of the entire picture field. It employs a battery check lever and 60/40 center-weighted metering. Two mercury PX-13 batteries are required.