Hi!
I would like to add that there exist a nice little program which may help you in measuring the shutter speed. The program can be downloaded here:
http://www.3dtv.at/Downloads/Index_en.aspx(see: Camera Sync Tester 0.1.1)
Direct link is the following:
http://www.3dtv.at/Downloads/synctest011.zipUnpack the program and run it in "DOS" mode (Start - Run)
write the following:
synctest.exe -x1024 -y768 -r100
where 1024 is screen width, 768 screen hight and 100 refresh rate. Of course - you can change the numbers to suit your monitor size and refresh rates.
How to measure shutter speed? Simply measure number of bright lines at known shutter speed (let's say 1/1000s), calculate time required for 1 line and then measure number of bright lines at some other speed.
I know that you are already using monitor for measuring speed, but the mentioned program displays numbers which helps you in counting lines.
Damir