How long does it take to get burn-in when watching widescreen content on a CRT TV?
 

I like watching widescreen movies and I like viewing them on CRT TVs but have been hesitant to watch them very much on my CRT TVs because I'm concerned about the image burning into the center of the screen and getting that widescreen burn-in. Does anyone have any idea how many hours of watching widescreen content on a CRT TV it would take to cause this type of burn-in? This is assuming that content is being watched at normal brightness and contrast levels.

Since burn-in happens very gradually, this is hard to answer, because it depends on how sensitive your perception of it is. To minimize it, your viewing of letterbox images should be as small a percentage of the total on-time as possible. Of course, this means using the CRT more for 4x3 images, and shortens the life of the CRT. There's no free lunch.

It would be nice to have a widescreen source that puts average grey in the blank areas instead of black, but I haven't heard of one that does it.

I would honestly just not do letterboxed on a CRT at all. I use mine exclusively for games and old TV shows for exactly that reason.

They have a limited enough lifespan as it is and I wouldn't want to do anything to hasten that.

I agree. Some users on the CRTgaming subreddit are claiming that they have operated their 4:3 PC CRT monitors using a widescreen resolution for hundreds of hours with no burn-in. One user even claimed they operated the monitor using a widescreen resolution for 1000 hours with no burn-in. I am very skeptical of this. Maybe PC CRT monitors aren't as prone to burn-in? I remember that when I was younger, my friend was playing a Playstation 1 game that had in icon in the corner of the screen as part of the game and after playing the game on his CRT for an entire day, that icon was burned into the screen and his parents were pissed. Granted, I had a 27" Toshiba CRT from 1994 that I used to watch widescreen movies on in the early 2000s and I never noticed burn-in. I probably watched 30-40 widescreen movies on that TV. I also never noticed any widescreen burn-in on my PC CRT monitors in the 2000s and on one monitor I must have watched about 100 widescreen movies. I'm still going to err on the side of caution but it's interesting. I probably won't worry if it's just a few widescreen movies on my current CRTs but I won't do much more than that.

On service calls I would see customers sets that were played several hours each day and I would see the burn in of the stock market reports that ran along the bottom, or the Weather Channel logo. During the first years of color TV, RCA cautioned leaving a color bar generator on too long. RCA said if burn in did occur, sometimes it could be "erased" by leaving the set running at high brightness with the vertical hold control set for a very fast roll.

A couple of things to consider: you don't have to watch a 16x9 movie letterboxed on a 4x3 TV. You can crop it (most VHS releases of movies did this), and there's several ways to do it. Many DVD/Blu-ray players have menu settings to select that, but for the ones that don't I offer 2 solutions in this video https://m.youtube.com/watch?v=hKjt3x4WtWU

If watching widescreen cropped bugs you another option is to track down a 16x9 aspect ratio widescreen HD-CRT TV. Sony, Toshiba, RCA and possibly others built such sets and I very much enjoy my ATSC and HDMI equipped Sony kd-34xbr960.