Shutter times in relation to what the eye can see

[steven_e007]

Try to cancel them out?

What if they add up?

Then you'd have to stamp a very different shutter speed on that setting for your shutter!

When I tested a rebuilt 'front of lens' roller blind shutter (circa 1870ish or something) on the front of an old Sanderson, I was amazed that the shutter speeds seemed to be about right. Now I think about it I reckon the numbers stamped on the dial had little to do with the actual time the shutter opened for... but the resulting exposure was in the right ballpark, so I was happy

 

[RalphLambrecht]

Then you'd have to stamp a very different shutter speed on that setting for your shutter! ...

That works for focal-plane shutters, but keep in mind the timing of a leaf shutter depends on the aperture setting. With leaf shutters, the effective exposure time at small apertures is longer than at large apertures.

 

[Q.G.]

That works for focal-plane shutters, but keep in mind the timing of a leaf shutter depends on the aperture setting. With leaf shutters, the effective exposure time at small apertures is longer than at large apertures.

That of focal plane shutters too (though perhaps to a lesser degree).
With larger apertures, the spread to the left and right of the slit aperture will be more than with smaller aperture, thus the exposures will be longer.