The Ricoh GR is equipped with a fixed 18.3mm f/2.8 lens, with a 35mm-equivalent focal length of about 28mm. Construction consists of 7 elements in 5 groups including two double-sided aspherics ...
But given the significant advantage for the Ricoh GR II in terms of weight and pocketability, it's perhaps still in a class of its own as of this writing anyway. 28mm-equivalent, 1/500 sec. @ f/5. ...