There's an old exposure rule that is probably next to useless now, but worked pretty well for film cameras when you didn't have a light meter: exposure of a sub

There's an old exposure rule that is probably next to useless now, but worked pretty well for film cameras when you didn't have a light meter: exposure of a subject in sunny bright conditions is an aperture of f/16 and shutter speed set to the film's ISO. So a starting place for a bright, sunny day when using Kodachrome 64 film would be f/16 at 1/60th of a second (or an equivalent aperture/shutter speed combination). From there an experienced photographer could estimate exposure for other lighting conditions. Of course, negative film (either color or black and white) is more forgiving of exposure errors than slide film. These days if your exposure meter isn't working, it means your whole camera isn't working...