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A7SII low light slow mo flicker issue. Please help!


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Hey guys, 

 

Desperately need your help.

 

Tried researching and I'm pretty sure I know what's causing it, I just don't know how to fix it. Whenever I shoot slow motion (120fps) in low light I get a TERRIBLE shutter flicker. I know it may be the lights themselves but is there a solve for shooting in these conditions?

 

I tried Phillip Blooms tip of overlaying the footage with the same clip, and move it one frame forward and reduce opacity to 50% but I have to move mine 3 frames and that creates too much blur.

 

Here is an example of my footage and issue:

 

SHOT @: 120fps 1/250 shutter.

 

https://vimeo.com/174189505

 

 

SO grateful to any insight on this...

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I'm not sure if this can be avoided. I'd try going to eoshd.com and ask the question as there may be solutions and, if there are, that's the site where you might find someone who knows. It's not Sony specific (although a lot of FS5/7 expertise) but as a dedicated cinematography forum it's an excellent resource. Not suggesting that this isn't but I think for general video questions eoshd is preferable!

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It looks like you are/were in Europe and you need to have a fps that matches the electrical current. 120 works in the US (60hz), it does not in Europe (50hz). Shooting at 100fps should have worked better. RED actually has a good explanation of it:

 

http://www.red.com/learn/red-101/flicker-free-video-tutorial

 

Even in the US, when shooting 120fps, which should be without flicker, you can still get it if there are LED lights. LEDs (most lights actually) that have been dimmed or have a power supply that's of poor quality can cause all sorts of problems.

 

The Flicker Free plugin deals with this type of problem and usually solves it. It's available for most editing apps. You can find out more about it here:

 

http://digitalanarchy.com/Flicker/main.html

 

Philip talks about it in this post:

 

http://philipbloom.net/blog/newyorksnow/

 

If you're going to be shooting slow motion, it's good to do a few tests before you start and view them on a monitor. Often you won't see the flicker on a small camera screen. Also, beware of dimmed LED lights in hotels and public places. It's pretty common for folks that have shot a wedding to need flicker removal because they didn't notice the dimmed LEDs that are everywhere in hotels these days. All that lovely, multi-hued ambient light on the walls of the hotel ballroom is the stuff of video nightmares. ;-)

 

cheers,

Jim Tierney

 

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