I create many of these comparison runs or comparison exercises.
However, I always have to adjust the brightness, contrast and colour tone of the upper track so that it matches the lower track.
As a test, I took 2 identical videos in 2 tracks.
Both tracks only have 2 filters for positioning:
Size, Position, Rotation
Crop: Rectangle
The upper video always appears slightly darker.
During editing and also after export.
What can I do to make both tracks appear exactly the same?
Here are 2 Pictures and the mlt.
The pictures look (here in forum) more identical than the exported video. Maybe the jpeg-compression.
@MusicalBox Thank you very much for your test.
It seems that you are right.
Maybe a problem of my pc-monitor?
I made a testclip (in Shotcut) with 3 colour-scales and a short video (of my comparsion runs).
And this 3 scales look up/down identical, but again my ârunâ looks on pc darker up and brighter down?!
Editing is unpleasant for me if the editing and result appears completely different to other users than it does to me.
I canât use the original videos without filters.
Above/below are mostly filmed in different sports gyms, or at different times of day (artificial light).
My smartphone doesnât produce perfectly lit films.
My pc-monitor is as well calibrated as I could make it.
Shotcut seems not the problem, but what can i do?
What version of Shotcut are you running, and where was it downloaded from? There were very old versions that could color shift from a blend bug, but that was fixed long ago. If this is a recent version, perhaps there is something unique about that clip that is causing one track to be interpreted as full range or BT.601 but the other track isnât. Could you send us one of those clips?
I exported a snapshot of your video (at around 00:16) from VLC and compared the top part with the bottom part again in Photoshop. And again, I canât see any brightness difference between the two parts.
But I agree that when looking at the original video, I do see a slight difference.
Iâm thinking that maybe there is nothing wrong with our eyesight. Maybe this is something like in this optical illusion where the 2 dots in the image appear to have a completely different brightness when they are in fact identical.
I have now compared 2 equally placed colour pixels directly in ShotCut.
In each case the pixel to the right of the brightest on my nose.
In the track below, the pixels are slightly brighter than in the track above (see the values on the left of my head).
So itâs not just a âfeelingâ.
What happens if you move the clips to new tracks (say, #3 and #4)? Or do it in order, first move base to 3rd, then 2nd to 4th etc to check if simply moving does anything or if the base track has some uninteded side effect.
Or if you reverse them between each other, do the same happens?
The presence or absence of the second track (the white text in that case) shifts the luma of the first track slightly, objectively measured by the waveform.
Next, looking at the same pixel on the lower image
They have the same values.
Another comparison using your project
Here the colors did change a little, but Y, which is luma (luminance), stayed the same
I had my filters on the clips as opposed to the track. Removing the Crop: Rectangle filter on the upper track of your project did not make a difference for me. I have not been able to find the reasons for the slight differencesâwhether between our projects or within your project (chroma).
