Varicam35: VC-HS flickering detection & monitoring during field recording

L

lonewolf2koc@hotmail.com

Well-known member
I'm struggling to figure out if there is any way to monitor flickering problems on the Varicam HS. When I shoot anything beyond the normal standard frame rate (60-240 fps) under fluorescent or artificial lighting, I can only see the flicker after it is recorded onto the Express P2 media. Most locations are international. I couldn't bring too many accessories - especially an external monitor. Playing back the footage on the built-in LCD doesn't show much flicker.

Currently limited to shooting high frame rate shots to outdoor with natural sunlight. Recently I shot an outdoor night X-Mas light festival and it is flickering considerably when frame rate is around 40-60 fps. Most LEDs are not video friendly. But fortunately, there is no flickering if it is shot in native frame rate and at full 360 degree shutter angle.
 
Unfortunately, most "high-speed flicker" is only going to be visible upon playback. What may help is to think of your frame rate as shutter speed and see if it lines up with the power frequency of the area you're shooting in(i.e: 60Hz US, 50Hz UK, etc.) and also dialing shutter in to match up(divisible) with the power frequency. But throwing consumer LED's in there complicates it, because of the different ways they may be powered or dimmed. I'm on a shoot all week where we are using a theater and projecting footage behind the subject(s). We're shooting real time at 24 (23.98)fps and slow-mo at 48fps, so we're shooting 1/60 shutter for everything to eliminate flicker. It was actually apparent directly on the monitor without playback that the projected image was flickering, but we still shot tests and played back to make sure it was going to work with the "corrected" shutter speed.

So I guess what I'm saying is the best thing to do is test. Even with taking limited gear, you can hopefully find space to take something like a 7" monitor, which should allow you to see any flicker, if present.
 
I have a Small HD 7" monitor. Their hood accessory is not well designed. That's when detaching the hood, those fragile contact point may break anytime. I've been leaving the lens hood as-is ever since. But your suggestion is actually makes sense. I prefer not to carry a laptop, P2 Express memory card reader, AC power, etc.. to detect flicker in the footage. 95% of the shoot is docu style. Can't bring too much stuff on location for a small 1-man crew. Between a 7" monitor and the laptop setup, I rather bring the monitor, 3/8" to 1/4-20" arm, BNC cables than the whole laptop and cumbersome AC cables, adaptors, etc.. But first I'll copy the flicker footage to see if I can playback on the color view finder instead of the VC-HS's built in side LCD. If that works, then the flicker detection problem is under some control and no need to bring any monitor at all.
 
You can experiment with different shutter angles at various frame rates. It isn’t the camera’s fault, the lights flicker and the high frame rate reveals it. But using some adjustments can sometimes mitigate the issue.
 
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