Weird color issues while shooting video on the A7s

[robertandrewphoto]

Having some issues while shooting video with my A7s, which I've only had for about 4 months or so.

 

There are these downward moving color shifts that go from warm to cool that show up in every clip. They are much more noticeable against whites, and a little hidden against blacks but definitely still there.

 

The lenses I'm using are a Sony 28mm f/2 lens, and a Vizelex ND throttle adapter with a Nikkor 50mm f/1.2 and 105 f/1.8.

 

The issue happens with any of these 3 lenses so I'm pretty sure it's not the adapter or Nikkor lenses causing the issue.

 

Video settings are MP4 and 1440x1080 12M.

 

Any insight as to why this might be happening and how it could be fixed are greatly appreciated.

 

[bennytan]

What shutter speed are you using? 

 

Generally, you want this to be double your frame rate, for a standard 180º shutter angle. You also want to account for the power cycle frequency in your country, especially if you're shooting near household/commercial fluorescent fixtures to avoid flicker and scanning.

 

Generally, North America is on a 60Hz cycle whereas Europe, Asia and Australia are on a 50Hz cycle. If you're on a 60Hz cycle, you'd be shooting at 30fps and want to keep your shutter at 1/60. You can cycle this to 1/120 if you want a higher shutter speed for less motion blur.

 

Also, using 1440x1080 is not standard for modern cameras. The 1440x1080 spec was used in tape cameras for easy adoption and matching with HD. With HD sources, you'd want to be shooting in 1920x1080 in as high a bit rate as possible for your project and post capabilities. On the a7S, I'd definitely recommend you consider shooting XAVC-S in a higher bitrate.

[VTC]

It's a fight between lighting vs. shutter speed.