[Boris Dimitrov]

Hi Braise,

Sorry, been out and away from my computer for a while. Here is a link to a copy of the clip. I will be hugely grateful if you can crack it and share insight on how you managed it!

[Boris Dimitrov]

Thanks for the suggestion! I am not 100% sure what you mean – use a track that gets poor results in terms of tracking points, but that can be used to create a camera, then manually place the objects in 3D space (not using the tracking points for solids/nulls)?

If the track is poor, wouldn’t there be a big risk that the camera movement is also off? I am concerned that I might end up spending a lot of time trying to get the composited layers to not float when it turns out that that was impossible due to poor camera movement data.

[Boris Dimitrov]

Those are excellent tips! I tried it out, and it really seems that the texture & contrast comes out sufficiently, but the AE tracker still fails. Here are 2 frames from the modified clip, 3-4 seconds apart. I uploaded two frames just to show how drastic the change in perspective changes the features on the ground, I am suspecting that this might be the reason why the track is still failing. I’ll keep experimenting to see if I can make it work with different contrast/sharpness and other image modifications.

I did have some success with Mocha Pro, managing to decently solve for a segment of about 1/3 of the total clip. I did it using:
– a unlinked (“Link to track: None”) layer of the foreground (ground closest to the camera) that covers 1/2 of the width of the frame in the center. I meticulously adjusted the surface plane to match the perspective of the ground plane as close as possible. Man it takes a long time to get it to feel right, and I am never quite sure (there are zero references to the perspective line).
– a second unlinked middle ground layer, covering the ground plane further in the distance, covering about 1/3 of the frame width in the center of the frame, once again with a meticulously adjusted surface plane.
– a third (linked) layer that covers the mountains in the back with a perfectly vertical surface plane

Using those 3 layers, the camera solved with 96% accuracy and had a decent track in AE. Problem is, even though those layers’ splines are fixed and do not move with the track, their surface planes/grids do and once they go near and beyond the edge of the screen, they warp in strange ways. So I could only get a good camera solve for a segment of the clip where the planes were mostly within the clip.

Last night, I tried making a second set of the foreground & middleground layers that start at about the place where the first set run off screen (setting out points for the first set at around the same place), but that worsened the accuracy of the camera solve to 92% and produced an unworkable track when brought into AE. Ill try and refine the second set to try and make it work.

I’ll keep experimenting. Ill probably buy a few planks, mark them with “X”-es and spread them out at different Z-depths in the actual shoot with the hope of being able to make it work.

[Boris Dimitrov]

Just played around with HSL Secondary some more and also read into how the hue vs hue curve works in DaVinci.

From what I am able to work out right now, the HSL Secondary is alot less versatile in selection/correction in the way it is built.
You basically make a selection in hue/sat/lum with ‘rolloffs’ on each side (is it me or is there no way to make the two ‘rolloffs’ on each side of the selection a different length?).
You then apply global corrections (by global i mean they apply to the whole selection, falling off gradually where those ‘rolloffs’ of the selection are) in hue/sat and other adjustments.

For comparison, if I understand it correctly, the hue vs hue curve in DaVinci allows you to make different adjustments to the different hues that comprise the selection with very precise control. You can, as Alan has done, shift greens alot, cyans a little less, and blues ever so slightly.

That seems to be precisely whats needed for the edit I need to do on my footage, and I can’t seem to find a way to do it with Lumetri as of right now.

I did download DaVinci, though.. it’s getting late, but ill dive right in tomorrow! 🙂

[Boris Dimitrov]

Whoaah! You should have seen the look on my face, heh.

I think I should in theory be able to get a similar result using the HSL Secondary tool in Lumetri Color, but my last attempt was.. less than stellar. Relatedly, think you might slightly be on the modest side regarding your skills/feel for how to do the right edit ☺

I’ll definitely give it another shot now that you’ve shown me its possible, if i am able to get it even close to what you have achieved, I think i’ll will have pretty much solved my problem!

Massive thanks once again for essentially shining a light in the tunnel!

[Boris Dimitrov]

Hi Alan and thanks for the tip!

I envy your skills if this seems like an easy fix! ☺ I am a Premiere Pro/Lumetri/Colorista user and dont have any experience with DaVinci Resolve, but I’l definitely either try and find a corresponding hue vs hue curves tool thats available in Premiere or possibly even try out DaVinci itself.

[Boris Dimitrov]

Hi Dave and thanks for your input!

After some research, it appears that the issue is specific to some Sony cameras that have irregular sensitivity to some variations of highly saturated purple/magenta and blue light, specifically from LED stage lighting (although I have found some mentions of the issue with architectural lighting as well). In case it’s of interest to you or anyone else, here is one of the more in-depth threads I have found:
https://www.eoshd.com/comments/topic/7172-sony-a7s-color-channel-clipping-issues/

TLDR:
when filming stage events with LED stage lighting with Sony cameras, stay at 5000K WB and one of the following creative style settings – “Clear”, “Deep”, “Light”, “Black & White”, “Sepia”, or “Autumn Leaves”. This will likely result in more postproduction work to get the right colors, but will minimize the risk of getting what is pretty much unusable footage with major color shifts and clipping.

It is unclear why this issue occurs and as far as I know, Sony have not taken any action to eliminate it despite it being a known issue for quite some time now.

I could probably live with the issue if it was just the color shift, but the horrible highlight rolloffs/clippings makes much of the footage unusable, like in the frame grabs below:
https://drive.google.com/file/d/1hfinBbIB84Fv17dNEPQIoNU8rE-J_CAx/view?usp=sharing
https://drive.google.com/file/d/1a0xNTAu0V-c72sbUnVQcb4jAFhgw8Bj8/view?usp=sharing
https://drive.google.com/file/d/1lziJPzyGSZi9nuji-nZZXSKRnKNGAQmI/view?usp=sharing

Thankfully we have some other cameras which will help us save this particular project, even if not with the best possible result. But definitely something we will be extra careful about in the future – never again will we agree to film without testing camera equipment with the full range of lighting that will be used for an event!