The Belair’s X 6-12 Auto-Exposure Range is: EV4 ~ EV15.
With ISO100 film, EV4 is equal to the light situation in a very dim restaurant. Under aperture f/8, exposure time is 4 seconds.Thus, if the light situation is lower than EV4, exposure time will work the same as EV4.
If using ISO100 film, correct exposure photo in a dim restaurant (EV4) is possible. If using higher sensitivity film, correct exposure is possible in even dimmer situations (e.g. with ISO400 film it is possible to take photos in EV2 – basically a candlelit room scenario).
If you’re after brighter results in a dark setting we recommend using a high ISO film or switching to B (Bulb) Mode. B Mode will expose your shot for as long as you keep the shutter pressed.