It's a good question, and it's a delicate question to ask.
You'd be hard pressed to find people on HN to believe that this enhanced footage is original. Why? Because this audience understands that these techniques exist and is able to apply their knowledge to what's presented to them.
However, the world is big and not all humans are in a position to spot the difference. Either because they never attained that level of education, don't have access to knowledge, lack the incentives to get educated, aren't aware of their own biases, and so on. This isn't a small group of people, and going out you're going to encounter people who would totally end up believing this is original footage if you primed them before showing them.
Now, you might think "Well, luckily I can spot that difference." but you're not entirely out of the woods either.
See, this is a clear example of altered footage. The contents and the time period are clear from what you see. But things aren't always that clear.
For instance, someone decides to make a documentary on a contemporary hot button topic. The premise of the documentary already aligns with your point of view on that topic. Now, the makers of that documentary could decide to spruce things by interspersing their film with carefully chosen, spliced footage which is subtly enhanced. That footage is then passed off as "fact" in order to make things even more poignant.
If you watch an hour long documentary containing five 5 second long shots with such enhanced footage, would you be able to pick them out as you are watching the documentary? Without anyone telling that those shots were there in the first place?
Now, to be clear, I'm not against enhancing footage. I think that's inevitable. And it's not a new thing either. Altered copies and mucking with documents has existed since the dawn of recorded history.
What matters, though, is understanding how these techniques could be used for better and for worse; but - above else - also daring to question your own biases and perspective on the world coloured by your personal circumstances.
I'll give two reasons why assumptions about general knowledge levels are biased:
Geography:
> The Council on Foreign Relations (CFR) and National Geographic commissioned a survey to gauge what young people educated in American colleges and universities know about geography, the environment, demographics, U.S. foreign policy, recent international events, and economics. The survey, conducted in May 2016 among 1,203 respondents aged eighteen to twenty-six, revealed significant gaps between what young people understand about today’s world and what they need to know to successfully navigate and compete in it. The average score on the survey’s knowledge questions was only 55 percent correct, and just 29 percent of respondents earned a minimal pass—66 percent correct or better. [1]
[1] https://www.cfr.org/global-literacy-survey
And, far more important, literacy:
> According to data from the 2014 U.S. Census Bureau, 21 percent — or nearly 60,000 — of working age adults in the city lack a high school diploma. At the same time, 19 percent of adults cannot read a newspaper, much less complete a job application, according to the National Center for Education Statistics. The situation is just as worrisome at a national level. Approximately 32 million adults in the United States can’t read, according to the U.S. Department of Education and the National Institute of Literacy. The Organization for Economic Cooperation and Development found that 50 percent of U.S. adults can’t read a book written at an eighth-grade level. [2]
[2] https://www.washingtonpost.com/news/answer-sheet/wp/2016/11/...
The real trouble with a digital world, in which the wide proliferation of these technologies is driven by their low cost and ease of use, is that entire strata of the human population lack the critical skills, time and energy to even remotely come to develop a critical view of anything which is presented to them.