Stop/start ? Out of synch?

Hi All. I have seen many interesting Model Railways on YouTube , but  some of the action is spoiled? By the Locos pulling away at “ break neck speeds “ with the sound being out of synch. and then either crawl or judder, on the remaining film? Is this something to do with the video equipment ? And with a lot of videos, there isn’t any scenery just bare boards or even running on carpet. And as for weathering it is non existent. Obviously “ A dry run “ is essential to test new wiring and track plans,  before any scenic work is done, but these Guy's and dare I say it, Girls,have been doing Model Railway fo quite a while, is it there job ? Are they sponsored by the medel shops that they are not shy to mention? or do they like to be seen and heard on YouTube ??
Best wishes. Kevin

Many Kevin, don't put their work on Youtube but within Forums like YMR or even their own web sites like BNSF FALL RIVER DIVISION - Welcome   or On Irish Tracks ~ Adavoyle Junction   or  Boulder Creek Railroad  and he has very good Youtubes videos  such as https://www.youtube.com/channel/UCjRkUtHQ774mTg1vrQ6uA5A/videos

Hi Ron.  Thank you for your reply. I see what you mean, I have just had a look, and unless I am mistaken Boulder-creek would like viewers to join and buy?   Best wishes.   Kevin

Boulder Creek wouldn't be the first modeller to attempt o make some money out of the hobby. Luke is also an airline p9ilot in his "spare" time.