There are a number of light meters built into film cameras I am aware of.
First there's selenium cell light meters, like on the below old Canonet.
Later cadmium sulphide (CdS) photocells became more common. This later Canonet model used one. It's right above the lens' front element.
After that silicon photocells started becoming the norm, with increasingly complex segmented meters using through-the-lens metering offering options such as center-weighted average metering, partial metering, spot metering and evaluative (Canon) or matrix (Nikon) metering.
Apart from the above types of meters (selenium cell, CdS cell, TTL silicon multi-segment), what other built-in meters did film cameras use? Is there some exhaustive list with useful categories?
(all images courtesy of Wikimedia Commons)