Time...vs real time

[egutie6970]

So i took video footage of myself at the track. I tried to use that to base my times that i got per lap but someone mention to me that, the video taken is actualy 'slower' or should i say faster, does anyone know how i can convert it to real time ?

Example :

I got 2 mins, but it really is 1 min 55 secs.

Thanks in advance

Enrique

[edDV]

Two issues.

1. NTSC video runs 59.94 frames per second. For correction multiply x60/59.94.

2. Internal crystal oscillators in camcorders free run at +/- speed error vs. 59.94. Two camcorders recording the same scene will drift apart over time.

Better to use a good stop watch.

[jagabo]

The question is how are you determining the time on the video? If you are watching an NTSC DV tape on an NTSC DV player the time should be very accurate.

The error you're seeing (120 seconds vs 115 seconds) is about 4 percent. That is far greater than any errors you should be seeing with video. In fact it is about the difference between NTSC (film) and PAL frame rates. So it sounds like you may have a frame rate problem.

[edDV]

True, the error over 2 miniutes would be on the order of thousandths of a sec for #1 and maybe hundredths for #2 unless the camcorder is abnormally off.