Huss
Member
I've only got one camera capable of altering exposure by less than 1/3 stop, and that only in certain shutter speed ranges. I'm referring to my Speed Graphic; the focal plane shutter in its slower ranges is able to produce some pretty fine gradients in exposure time. Nothing else I own can divide a stop any finer than 1/3 stop, and most of my cameras only do half stops.
I think the Nikon F2As has stepless shutter speeds. Leica M7 does but that is electronic. And pretty much any of my cameras that have lenses with aperture rings can be adjusted as finely as I want.