Weird horizontal lines in my video

Started by Metsadah, November 26, 2014, 08:20:19 AM

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Metsadah

Just wondering if this is a RAW Post processing thing or some interference going on with the lights, I hope you guys can help me out. Its really visible in the exported file, on vimeo a bit less. But you should notice it definately on 2:45 in the background:

https://vimeo.com/112864613
pass: feest

I used to extract the DNG's with RAWMagic, 12 bit, vertical stripes checked, auto black lvl. Its the same with 16 bit.
Its not really visible in the proress files I got out of DaVinci after applying VisionLog, but when I start grading it it becomes visible. I chose a very flat look, since more contrast makes it worse (and flat was what the client wanted anyway).


Levas

I had to look many times to even notice what you mean.
But right about 2:50 I think you mean the many horizontal lines in the blue background.

My guess, same as you already guessed, interference with the lights.
In PAL countries, including the Netherlands(gok aan de titel van de video dat je in Nederland woont  ;) ) the electricity is 50hz.
That means 1/50 of a shutter time is often the max when lights are used.
In this case it could be that you're shutter time is a little off or the power network is not exactly 50hz.
With fps override you can tweak the shutter time a little, for exact shutter time.
When you're using a shutter time lower then 1/50, it should be gone, so next time use 1/33 or 1/48.

What shutter time did you use for this video ?

Metsadah

thats the thing, Im pretty sure it was 1/48 since I shot it in 24fps. Maybe it would have been  better to shoot it in 1/50 and 25 fps then.

Thanks for the response!

kyrobb

I've experienced the same thing using both my 50D and 550D shooting 1/48 24fps in both RAW and H.264, so I had also assumed some sort of light interference was the cause.