Timescapes - Digital Timelapse Discussion
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Periodic pause in post production
http://forum.timescapes.org/phpBB3/viewtopic.php?f=40&t=11760
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Author:  Photosbykev [ Thu Apr 10, 2014 2:32 am ]
Post subject:  Periodic pause in post production

Hi, it's been a long time since I've posted anything but work gets in the way lol.

I recently shot a simple timelapse on a static tripod using a Canon 5D3 and 24 f1.4L II USM lens. It was 700 frames shot in raw, each 6 seconds exposure with the camera locked in continuous drive mode so the remote release was just locked down. The images were converted to tif, adjusted in PS and then put together in Premier Pro at 24fps.

In the video there appears to be a slight jump/pause at about 1 second intervals which I just can't figure out. It isn't something I've seen before so if anyone has an idea what is causing it I would be grateful for the answer. The camera was in full manual, no noise reduction and the lens in MF.

http://youtu.be/lkswU2K3m64

regards
Kev

Author:  Photosbykev [ Thu Apr 10, 2014 3:33 am ]
Post subject:  Re: Periodic pause in post production

I think I've sorted it out. Looking at the exif data on the images the time interval is varying between 6 and 7 seconds which shows up as a small jump. I'm thinking it is a buffering problem even with a fast CF card so I need to introduce a slight delay between shots rather than just use the continous drive mode.

regards
Kev

Author:  Antz [ Thu Apr 10, 2014 3:34 am ]
Post subject:  Re: Periodic pause in post production

Most likely a difference in your footage import/interpretation frame rate and your sequence frame rate, or the output render frame rate.
Make sure all 3 are the same.

Author:  Photosbykev [ Thu Apr 10, 2014 4:26 am ]
Post subject:  Re: Periodic pause in post production

Antz wrote:
Most likely a difference in your footage import/interpretation frame rate and your sequence frame rate, or the output render frame rate.
Make sure all 3 are the same.


I think that was the problem, I'd imported at 25fps and exported at 24fps. I've recoded the video at 25fps and uploaded it to Youtube, I haven't deflickered the sequence.

http://youtu.be/jfF_6dBjP4A

Thank you for the help Antz. I do think I was being a bit lazy just using the continuous drive mode.

regards
Kev

Author:  Antz [ Thu Apr 10, 2014 9:21 pm ]
Post subject:  Re: Periodic pause in post production

I generally use the continuous drive mode for all my star shots now, it gives a smoother more pleasing look overall I think.

Author:  Photosbykev [ Thu Apr 10, 2014 11:38 pm ]
Post subject:  Re: Periodic pause in post production

Antz wrote:
I generally use the continuous drive mode for all my star shots now, it gives a smoother more pleasing look overall I think.
if the exposure is less than 30 seconds then I usually use continuous as well but I'm certainly seeing a small variation in the shot spacing checking the exif data. I know there will be some rounding error on the time reported in the exif but the spacing between shots isn't always the same. This is when I'm using a Lexar Pro x800 64Gb CF cards, the final timelapse has now been deflickered although there wasn't very much to start with and I've also used frame blending. The final version can be seen here http://youtu.be/7NKbq4FmAQo

regards
Kev

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