The ones created in Posers root directory during a render and deleted (hopefully) at its completion.

i.e. poserTemp.-1131500913

As one is created for each light, Ive always assumed they contain the lights shadow map info, and, if so, it would be really handy to actually be able to visualize these, to figure out whats going on sometimes.

Any of you file-hacking smart guys ever open one up to see if you could decode an image?