Very long-time readers of this blog will remember a proposal I made 10 years ago that cruise ship inside cabins use HDTVs with the outside view. Now a cruise ship is launching with such a system, though bigger than I proposed.

The Royal Caribbean vessel will feature an artificial balcony using an 80 inch screen including a fake railing. While the cameras used are 4K, I suspect the screens will only be HDTV, since 4K 80 inch screens are hugely expensive right now, though very shortly they will be quite affordable for this.

It will be interesting to see if the virtual balcony approach does much better than just using something meant to look like a window, which frankly would be a bunch easier though not get that 3D effect from the railing. (The fact that the image and railing are at the same focus distance may actually complicate things.) I think an interesting approach would be instead to use a screen with infinity optics, which make the screen focus as though it is at infinity. This requires space outside the room, which you could get by having two adjoining cabins each take a box out of the other cabin for the mirror and lenses. (Though doing really good collimated light takes a lot of space which is at too much of a premium in a cruise ship, though perhaps not as much in interior cabins.

The sample photo shows a rather large stateroom -- usually interior rooms are small and for those who can't afford a window, but this might change. One reason people tolerate interior rooms is they plan to spend very little time in the room not sleeping, but the reality is that even doing that, it is disconcerting not to have the subtle cues of real exposure to day and night, waking up and not knowing what time it is. It generates a greater feeling of being closed in to be in a small enclosed and windowless space, compared to large interior spaces. As I pointed out before, having a view of the real horizon helps a lot with seasickness.

If this is a success, it could lead to several things:

• Ability to sell many more interior rooms, making better use of space in the middle of the very wide ships desired today.
• Low, central cabins have the least sway, but in the past were not popular with the seasick because that's much worse without a window.
• People might actually choose a larger, interior cabin at the same price as a much smaller, exterior cabin. Even if you plan to spend only modest time awake in your cabin, life in a larger cabin is more pleasant.
• Virtual walls could be put on multiple sides of the cabin, so you get the illusion of an owner's suite, with views in all directions.

To really get a super effect, you could even have people wear 3D glasses in the cabin -- polarized ones that double as sunglasses if you can make the screens bright enough. These allow you to do a special trick if there is only one person in the room, which make the screens simulate parallax, so that as you move your head, the background moves as though you are really looking through a window. Most ocean scenes are not very 3D themselves. It is debatable if this would be good enough for people to find it worth wearing the glasses, and of course there is the issue of dealing with only one person in the room. You can handle 2 people in the room if you have shutter glasses, very bright screens, and 240hz or faster displays. Handling 2 is probably enough -- turn the effect off the very rare times you have guests.

Finally, I would even wonder if it made sense to pipe in outside air on demand.

4K displays can get close to eye resolution depending on the viewing distance. Interior cabins on cruise ships are dismal places, and so if this can make them more palatable, it can be financially worthwhile.

Disney has also been doing this since 2010, I have learned, with a virtual porthole. They also add animations to the video (of Disney Characters peeking in the window) which presumably the kids like. Reports are this has caused a major boost in their inside cabin sales.