I am shooting timelapse sequences with my 1Ds Mark II and the TC80N3 controller. My exposures vary from 15 seconds to 1 minute in length. I have noticed that a 15 second exposure takes 15 seconds to write to my memory card. A 1 minute exposure takes an entire minute to write my memory card. A normal exposure writes quickly.
The problem with this is the buffer fills up quickly and won't take any photos until it finishes the long write.
What's up with this?