70-200 f2.8L II and 7D - Looking for advice and pictures

Started Dec 25, 2012 | Discussions thread
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tvstaff OP
Senior MemberPosts: 1,343Gear list
Re: A test for checking shutter speed calibration
In reply to GPapa, Dec 26, 2012

GPapa wrote:

When my 20D shutter failed it didn't just stop working. It slowed down. In fact it worked at low shutter speeds but fell increasingly short of specification at high shutter speeds.

You can test shutter speed accuracy by putting the camera in TV mode.

Select a subject in mixed sun/shade.

Select the slowest shutter speed where the camera can select an aperture with proper exposure. Say 1/200 Take a shot.

Now up the shutter speed to 1/400. The camera will choose a different, wider aperture to give you a properly exposed image.Take another shot. Be sure to meter off of the same spot on the subject.

Keep raising the shutter speed incrementally all the way to 1/8000.

Now go look at the images. They should all be exposed approximately the same. If the shots with high shutter speeds are over exposed then your shutter mechanism isn't really operating as fast as it should so the exposures are longer than expected by the camera software.


This is very interesting.  I will try this tomorrow.  Thank you for taking the time to respond.  Best regards to you.  TVSTAFF

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