Time Lapse Flicker Issue

[RandomlySet]

Hi,

I'm filming some time lapse for the distribution center we're having for work. The time lapse is indoors of racking being erected for pallets. No artificial lighting, just the sun through the skylights.

I set up Monday morning and went back late afternoon. After playing in LR, exporting and then dragging into AE, I noticed some flicker. So I did a little research online.... (Settings were AV mode at F16 giving a 1 second exposure, and 30 second intervals)

I have never suffered from flicker in previous attempts, which have all been outdoors.

Anyway on to today. I went for max aperture in AV mode which has given 2.5-3 seconds exposure time (30 second intervals). I thought by having a longer exposure, it'd help reduce noticeable flicker.

When I looked into flicker issue on Monday, it mainly discussed fluorescent lighting and to have an exposure greater than 1/50 to allow a cycle of electricity. Now this has got me thinking. To allow for a long duration, the camera is plugged into the mains. Could this be the cause of the flicker?

 

[RandomlySet]

Here's the video from today, and the evident flicker

View: https://www.youtube.com/watch?v=qiojul9fWlw


Like a dick, I left Auto Focus on

The problem I'm facing is that I am setting up at 7am, and the camera is located on top of a cabinet mounted about 20-30ft up. So I'm on ladders and unable to get to the back of the camera.

I'm hoping to try another angle tomorrow, but a source of power is an issue. If possible, I want the far corner that you can see in the video. Place it on a tripod and spend more time setting up and run everything in manual mode rather than AV.

 

[TimmyG]

Looks like there are some big skylights in that building, so natural light will be coming through. Passing clouds etc. will affect the overall exposure and I suspect contribute to your flicker problem - colour temp seems to be shifting considerably too. Did you have it set to auto by any chance?

. Years ago I was playing around with Time Lapse and had a similar issue due to the type of lighting I was using (tungsten I think...) I did find a utility that did a good job or sorting it out in post processing, I can't remember which one I used but it would be worth googling for some options (the one I used was free).

 

[Foxbat Flyer]

Have you tried using the camera in manual mode? The flicker could be caused by slightly different exposure times due to variance in light levels.

Chris

 

[RandomlySet]

Looks like there are some big skylights in that building, so natural light will be coming through. Passing clouds etc. will affect the overall exposure and I suspect contribute to your flicker problem - colour temp seems to be shifting considerably too. Did you have it set to auto by any chance?

. Years ago I was playing around with Time Lapse and had a similar issue due to the type of lighting I was using (tungsten I think...) I did find a utility that did a good job or sorting it out in post processing, I can't remember which one I used but it would be worth googling for some options (the one I used was free).

Yes, WB was in Auto.

I've never had (noticeable) flicker issues before, but that said, everything I've done has been outdoors and over a time of about 60 minutes at 1-10sec intervals.

Have you tried using the camera in manual mode? The flicker could be caused by slightly different exposure times due to variance in light levels.

Chris

Usually I go full manual. But due to light levels, I was in aperture priority.

I'm going to go through random images (say every 20th one), make a note of the exposure time, and what appears to be happening in shot, and go from there. It may well give underexposed images at 7:30am, but if the main action isn't happening until 10am, that's probably not going to be too much of an issue.




Also waiting for one of the IT lads to pop back to this office to I can install a Deflicker plugin in After Effects

 

[RandomlySet]

ETA:

Just taken exposure times for every 15 minutes, and here they are


Time - Exposure (seconds)
07:15 - 2.5
07:30 - 3.2
07:45 - 5
08:00 - 3.2
08:15 - 2.5
08:30 - 2.5
08:45 - 2
09:00 - 1.3
09:15 - 1.3
09:30 - 1
09:45 - 1.6
10:00 - 1.3
10:15 - 0.6
10:30 - 1
10:45 - 0.5
11:00 - 1
11:15 - 0.5
11:30 - 0.5
11:45 - 0.6
12:00 - 0.5
12:15 - 0.5
12:30 - 0.5
12:45 - 0.5
13:00 - 0.5
13:15 - 0.5
13:30 - 0.5
13:45 - 0.5
14:00 - 0.5
14:15 - 0.8
14:30 - 0.8
14:45 - 0.8

As you can see, from around 11am, it steadies out to 0.5 seconds. Whilst I understand the weather, sun etc will be different tomorrow, this has been my 3rd attempt, and will have to make an assumption the weather will be similar to today.

So I'll set the exposure to manual at 0.5 seconds.

 

[kman]

There are a few things that cause flicker in timelapse - firstly be careful of adjustments made to images in post - things like curves, shadow/highlight adjustments are non-linear (so they have a differing effect on an image as the composition changes e.g. when someone walks in front of camera).

You can also get flicker because of aperture open/close time variations so shoot a wider aperture as you can whilst maintaining desired dof.

Also set your white balance needs to be fixed (someone has mentioned already)

VirtualDub, MSU Deflicker are plugins to consider also gbdeflicker if you have AE.

Shutter speeds - use higher speeds to avoid shutter flicker from mechanical inconsistencies - .5s is still quite slow - use ND's to get it down to 1/100s or so.