hi umut

no, you need a light meter, not to worry, even cheap seckonic meters have a "cine" reading, you should be OK.
the camera is a double-8 mm camera meaning it takes 16mm film that you run the the camera 2x
one way, then the other ... ( to expose both sides ) when you send it to be processed they will slice it down the middle
and splice the 2 ends together like they are supposed to. what i meant by the focus and aperture are the same ...
( at least with the ones i had ? ) the distances and fstops were the same so as you opened up the lens you changed the focus
and when you stopped down the lens you changed the stop ... in other words, there wasn't a separate aperture ring, it was just the focus.
maybe the lenses i was using were "different" than what people usually use (yvar + switar ) or i was totally clueless ( could be )
... it was kind of trick sometimes .. but it all worked out in the end ...