This post was last modified: 2020-02-20, 14:18 by jorn-t.

Hi!

I've rendered a few clips with areas of high contrast and detail, and with animated zoom. On the finished YouTube video, the areas containing the most contrast and detail tend to flicker a lot, with intervals of about 0.5 seconds. It's not like the "contrast flicker" that I sometimes get when deflickering in LRTimelapse, but a more steady flicker affecting areas of high detail throughout the clip.

Could it be that the compression algorithms get problems with the amount of detail when combined with zoom animation?
The problem get's a whole lot worse if the camera is shaking slightly.
I now have razor sharp Sigma Art lenses and use pretty strong contrast and clarity, so the clips are very very sharp - maybe too sharp?

Workflow is :

1. 46 mpix 14-bit Nikon RAW files.
2. Zoom animation in LRT/Lightroom and export/resize to TIFF16 4k UHD. Clarity often +30-50. Default sharpening settings in LightRoom.
3. Render to ProRes 444 Ultra High Quality 4k UHD, with sharpening.
4. Render in Premiere to h.264 4k UHD, 300 Mbps
5. Upload to YouTube 4k UHD.

Added an example image. The highly detailed rock field in the middle of the picture would most probably flicker when doing zoom animations.

Any suggestions? Buy softer lenses maybe?


Kind regards,
- Jørn

To make Ken Burns animations in LRTimelapse often is not the best solution, simply because Lightroom crops to full pixels - this might introduce some jitter.
Could you try exporting and rendering without the Zoom effect and see if the problem is gone? In your case I would then recommend to add this zoom (if you really need to) later in the video editing. Video editing programs will do the zoom on subpixel basis which is smoother.

Thanks for the information Gunther, i was not aware that Lightroom resizing would/could give poorer results. I did a lot of experimenting years ago, also using RAW sequences directly in Premiere Pro for the best possible quality, but I must admit I thought Lightroom had one of the best resizing algorithms. Also, I experienced that LRTimelapse gives very good quality renders compared to rendering in, for example, After Effects or Premiere.

As I've now got roughly 1500 timelapse sequences on my hard drives, 500-750 000 RAW images and almost all sequences have LRT/LightRoom zoom animations (I guess I love Ken Burns), I was a bit sceptical to export everything in full size. However, I've just invested in a 28 TB temp/render RAID setup expandable to 56 TB, plus 64 TB internal permanent storage in addition to 80 TB external, and finally have the space to do full size exports and also 8K possibilties. Will have a go with full size exports the coming week and let you know the results.

I think if I sync crop settings in LightRoom without saving the metadata I can at least "test run" a lot of sequences, and then revert to old settings by loading metadata again, in case it didn't fix the problem.

:-)

Also interested in tips regarding 8K HDR workflows. All HDR renders I've done using tutorials on the internet, turns out to have very dull and flat colors/contrast...

Seems like you were absolutely right Gunther.

After un-cropping all RAW files in LightRoom, rendering in OriRes, then to ProRes also in original resolution, it seems like the flicker is almost gone on the final render. There is no flicker without the zoom animation, btw.

I also rendered with sharpening turned off and did a slower zoom-animation to eliminate the most of the remaining flicker.

Thanks :-)