Guys, I think I am getting some noise - a little bit of horizontal scanning lines appear when I throttle up, they can be somehow seen on the beginning of this video:


Can you check it out and tell me if that's fine, and I won't get any better than that in terms of video quality?
Or maybe adding low esr cap to battery leads would help? ( I did not add any on this quad)

I cap would probably help, but I wouldn't bother, particularly since it's your flight video.  It appears to be very slight.  Just my .02 cents worth. 

Honestly, that's better video than either of my quads!

However a capacitor is never a bad idea. I have one on one of my quads since the noise back off the ESCs was causing the camera to cut out completely on flips. If you're curious about this stuff then Drone Mesh did a few videos comparing LC filters and different capacitors.

Your video doesn't look bad at all. You could add a cap but I've seen much worse. I've used both LC filters and caps. On one of mine the LC filter worked perfectly, on another the filter did nothing and I had to use a cap. Depends on the frequency and cause of the noise.

Your fpv video is really better than mine too.
I added a 1000uf low esr 25v on lipo pads on fc. It helped a lot with twitchings problem but just a little or almost nothing on video quality

I think most of us would be happy with video like this without cap.

I want to use the LC, but my Armattan Rooster have zero space to stick it in.