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On 7D flash synch speed

Started Nov 7, 2004 | Discussions thread
JackRiley Senior Member • Posts: 1,136
Re: On 7D flash synch speed

Actually, the shutter speed cannot be faster than the speed at which the entire sensor is uncovered for a time. Any faster speeds would involve a moving slit across the image plane. Unless of course if you are using an FP flash mode.

That speed that I refer to above, is evidentally 1/160 of a second. For instance, my 20D gets sync at 1/250. I contend that the springs used in the D7 shutter are not strong enough to produce an uncovered sensor at speeds faster than 1/160. And I believe, from what I've read, is due to a decision on KM's part to not use a stronger shutter spring, because the result is shutter vibration that interferes with the AS.

Geir Ove wrote:

Alex Escada wrote:

Sync speed is a limitation of the shutter, expensive shutters are

This is not entirely correct. As I said in my original post, the
shutter speed cannot be faster than the duration of the flash in
situtations where you want to fully utlize the power of the flash.

Geir Ove

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