Original: The acronym EOS was chosen for Eos , the Titan Goddess of dawn in Greek mythology , and is often pronounced as a word ( i.e. , EE-oss ) , although some spell out the letters , reading it as an initialism .
Simplified: It competes primarily with the Nikon F series and its successors , as well as autofocus SLR systems from Olympus Corporation , Pentax , Sony\/Minolta , and Panasonic\/Leica .