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Thread started 20 Feb 2011 (Sunday) 23:39
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Why are shutter speed and exposure time frequently a bit different

 
dlwalke
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Feb 20, 2011 23:39 |  #1

based on the EXIF data. So for example, the shutter speed might be 1/128 seconds and the exposure time 1/125 seconds. I have a lot of pictures like this with minor discrepancies between the two values.




  
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Crazy ­ Horse
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Feb 21, 2011 00:32 |  #2

"Shutter speed" and "exposure time" are synonymous. I'll have to look at an images EXIF to see if I see this as well. I haven't noticed before.

I can't understand why they would be different.


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Crazy ­ Horse
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Feb 21, 2011 00:39 as a reply to  @ Crazy Horse's post |  #3

I just looked at the exif info of an image in Photoshop. It doesn't give me a "exposure time" but it does list "F-stop" as 4.5, and "aperture value" as 4.4 for the particular image.

Odd.

Perhaps an inconsistency in rounding?


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canonloader
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Feb 21, 2011 03:32 |  #4

Most cameras with chip controlled shutters actually set shutter speed by the amount of light the sensor sees, to give a perfectly exposed shot based on aperture size and ISO settings dialed in. The 1/125 is a dial setting, but if 1/128 gives a perfect exposure, that's what the shutter will use.


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Why are shutter speed and exposure time frequently a bit different
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