4k Lens Correction Problem Round 2

Trekz

Member Joined: Oct 16, 2016 00:32 Messages: 67 Offline

Solved by

Nov 14, 2016 03:21

I already contacted cyberlink, and I was replied with a "thank you for informing us" answer, and that was about it. This is posted to bring awareness for people looking to use the often required lens correction on their DJI Phantoms. I watched a previously PD15 produced lens corrected video on my cousin's 4k tv, and the banding was prominently there. If anyone has a solution to this then please let me know.

https://www.youtube.com/watch?v=oGAH_FvafjA&feature=youtu.be

ynotfish

Senior Contributor Location: N.S.W. Australia Joined: May 08, 2009 02:06 Messages: 9977 Offline

Nov 16, 2016 14:35

Hi Trekz -

I have an apology to make to you. In Round 1 of your Lens Correction issue, I insisted that I couldn't find any evidence that applying lens correction introduced any visual artifacts... & I was wrong. Sorry.

In that thread, I referred to it as "banding" which may or may not be the accurate term... but it'll do for the purposes of this discussion.

Since then, I've played with it quite a bit using a variety of DJI 4K clips and I've found that the banding is more pronounced/obvious when:

An incorrect lens profile is applied (Osmo is way worse than Advanced)

There are deep coloured gradients (e.g. sunrise or sunset skies)

The clips are shot in 4K (4096x2160). I haven't been able to replicate the same issue with DJI UHD clips (3940x2160)

The produced files are viewed on a 4K monitor/TV

Gathering evidence by screehot is difficult, because the banding is most obvious in playback. I've attached some partial screenshots.

Sample produced clips:

Produced with no lens correction

Produced with Osmo lens correction profile

Bottom line - used the Advanced profile, not Osmo. Shoot in UHD, not 4K.

Cheers - Tony

Filename	DJI LC.zip	Download
Description
Filesize	6229 Kbytes
Downloaded:	278 time(s)

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Trekz

Member Joined: Oct 16, 2016 00:32 Messages: 67 Offline

Nov 16, 2016 14:50

Quote Hi Trekz -

I have an apology to make to you. In Round 1 of your Lens Correction issue, I insisted that I couldn't find any evidence that applying lens correction introduced any visual artifacts... & I was wrong. Sorry.

In that thread, I referred to it as "banding" which may or may not be the accurate term... but it'll do for the purposes of this discussion.

Since then, I've played with it quite a bit using a variety of DJI 4K clips and I've found that the banding is more pronounced/obvious when:

An incorrect lens profile is applied (Osmo is way worse than Advanced)

There are deep coloured gradients (e.g. sunrise or sunset skies)

The clips are shot in 4K (4096x2160). I haven't been able to replicate the same issue with DJI UHD clips (3940x2160)

The produced files are viewed on a 4K monitor/TV

Gathering evidence by screehot is difficult, because the banding is most obvious in playback. I've attached some partial screenshots.

Sample produced clips:

Produced with no lens correction

Produced with Osmo lens correction profile

Bottom line - used the Advanced profile, not Osmo. Shoot in UHD, not 4K.

Cheers - Tony

No worries; it'all good. Thank you for actually taking the time to figure out the best setting. I'll change it to 3940x2160 for now. That was a beautiful shot. I don't get to see many reflections like that around where I live. I didn't even know what it was called when I first saw it, but I knew there was a difference.

Thank you again Tony aka ynotfish ( I was always reading your name as (k)notfish for some reason....)