shutters

[andnowimbroke]

First curtain slides up to reveal the image. Once image is "properly exposed", second curtain slides up. Then both curtain slide back down together to the reset position for the next shot. My question is why do they travel back down together? Can

[piiooo]

There is a phenomenon called shutter distortion, which occurs when you photograph fast moving objects using relatively long exposure time while NOT panning. When the first curtain slides up, the bottom of the sensor gets to be exposed first, and by the time the top part of the sensor is exposed the object could have (slightly) moved.


Knowing that your shutter will open and close predictably instead swinging back and forth, you can control or even apply the shutter distortion more effectively. I think...

[Fast Glass]

I know that you have to open and close it from the same direction because the one half of the image will be more darkly exposed than the other. But why they have to both come back down is still a mystery for me also.[^o)] Mabye it's more expsive to manufacture that way?


John.

[PaulM]

Perhaps the precise timing for the shutter movement is only economical to implement in one direction. I recall that my EOS 1 and 3 film cameras where the shutter is easy to watch with no film in the camera, the shutter curtains were noticeably slower on the return unless a power booster was attached.


I

[andnowimbroke]

That