HandBrake review
The brightest shot in a video can survive compression just fine while the low-light scene next to it starts to look blotchy. HandBrake can encode a short preview with the settings you’ve chosen. That’s where I’d spend a minute before committing to a long export.
Preview a scene that gives the encoder trouble
Open the source and choose your output settings. Select Preview in the toolbar, move over the preview window and use Position and Duration to pick a short section. Start Live Preview and play the clip when it’s ready. I’d pick a scene with motion or shadow detail, where it’s easier to see what the new copy lost.
Make one change and compare the same clip
If the preview looks too rough, adjust the quality or pick another preset. Run another preview on the same section. Comparing different scenes makes it harder to tell what the change did. When I’m happy with the preview, I’d encode the full copy and open it in VLC media player for a final playback check.
HandBrake artwork by Matt Johnson. Copyright HandBrake Team (https://handbrake.fr). Resized without cropping under CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/). The original is at https://github.com/HandBrake/HandBrake/blob/master/graphics/Logo/HandBrake-v2-1658%C3%971721.png.
Anabel’s take
I’d test the least forgiving ten seconds first. If the movement still looks clean and I can see detail in the shadows, I have a better starting point for the export than I would after checking the opening titles alone.