Corner Pin effect is messing up the colors

[saraf61840248]

Hi there, I've used Corner Pin for years and didn't notice anything weird about the video colors until now that I am getting chromatic noise (shades of magenta, mostly in the whites) right after adding the Corner Pin effect to my clip. I don't need to move the corners to see the messed-up color. I can see it even before applying any Lumetri Color changes right in the V-Log original footage. I used to record with a GH5 and never noticed this, but now I am noticing this in the GH6. Other effects under the Distort tab in Premiere don't add these magenta artifacts, only the Corner Pin. 😞

After exporting, the problem persists. Here are two before and after examples.

Can anyone help, please?

Footage: Panasonic GH6 V-Log 4K

Computer: iMac 2017 i7 Radeon Pro 580 8 GB with 64GB RAM - MacOS Ventura 13.4

Premiere Pro version: 23.4 (May 2023)

[Mhagelst]

Hi! 

Could you provide some more info? The GH6 can shoot V-LOG in several codecs and compressions, so I just want to make sure we're testing with the same files. (If you can provide a sample + a project even better.)

It would also be interesting to know the Sequence Color Space settings and if you're using a codec that is using Hardware Accelerated Decoding. If you turn off Hardware Accelerated Decoding in Preferences > Media, does that make a difference? 

As a final comment, I'd like to mention that the Corner Pin Effect is Non-GPU Accelerated and 8-bit only effect, so you will definitely experience a loss of quality using it on 10-bit footage.

[cristianafelgueiras]

Hi Mhagelst, thanks for your quick reply! And sorry I didn't notice your response before.

I found that exporting the clips (in my case I use the 4K YouTube Preset) with the color correction and then re-inserting them in the project to apply the Corner Pin effect does the trick.

I suspect it must be the 8-bit/10-bit issue that you are pointing out. My current footage is 4K 10-bit 420 150Mbps. Before, when I used the GH5, I did film 4K 8-bit 420 100Mbps (although you can also record 10-bit with the GH5).

My Sequence color space is Rec. 709. I have the Hardware accelerated decoding turned off. So I suppose the answer is that it doesn't help. I'm not sure what this means, by the way. Do you think I should work regularly with it turned on?

Thank you so much!

[cristianafelgueiras]

Oops, using a different login account but still me. 🙂

[SophieWorks]

I'm having the same issue on GH5- did you every find a solution to this?