What is High Definition Broadcasting and how does it affect make up and hair artists?

HD Broadcasting provides a resolution that is substantially higher than that of the standard-definition television. As a future makeup and hair artist, whenever I watch a movie, especially a horror or a sci-fi one, I always pay attention to the character's makeup and hair, to see if there are any mistakes or to figure out how the makeup was done.
For instance, the latest really good movie I watched is the famous 'The Revenant' with Leonardo DiCaprio in the main role. I must say that I payed more attention at the makeup (from nails to face) than the actual action. I was fascinated by how realistic the makeup was done, so I made some research.

I mean..just look how realistic this looks like! 

I found out it's very important the makeup is flawless, without imperfections because the audience will watch the movie in HD.

<A scene from The Revenant which shows the main character being savagely mauled by a bear is one of the most gruesome you're likely to see all year.

And to make Leonardo DiCaprio's wounds look realistic, it's been revealed that the actor had to spend up to five hours in the chair with Duncan James - a make-up artist from Watford, Hertfordshire.

Now an image of Leo, 41, having his prosthetic wounds applied by Duncan has been viewed more than 2.8 million times on Imgur. >

<Duncan's previous work includes Harry Potter And The Deathly Hallows: Part 2, The Grand Budapest Hotel and The Last Samurai, and he was key part of the prosthetics team on The Revenant, which tells the true story of legendary fur trapper, Hugo Glass. 

Glass is brutally attacked by a bear and left for dead by his hunting partners, but he miraculously survives and embarks on a quest to escape the wilderness and get his revenge on the men who betrayed him. >  

Ref: http://www.dailymail.co.uk/femail/article-3406685/How-make-artist-created-Leonardo-DiCaprio-s-bear-attack-wounds-Revenant.html