When I ask people to watch a 4K 360 video on their phone (e.g., to see it in 3D 360), many of them reply that they can’t because their phone doesn’t have a 4K screen. Do you really need a phone with a 4K screen to watch 4K 360 videos?
Answer: False.
Most smartphones with 1080p screens or better have sufficient resolution to view 4K, 6K, or even 8K 360 videos. This is because with 360, you are only looking at a cropped portion of the full video at any given time. Here is an equivalence chart by Visbit.co:
According to Visbit’s study, 8K 360 video has a theoretical resolution similar to a 1920 x 1080 conventional non-360 video. Therefore, a phone with a 1080p screen has sufficient resolution to show even 8K 360 video. If you don’t believe this, you can view this 7200 x 3600 360 photo from the Samsung Gear 360 on your phone — the photo has a similar resolution to an 8K video (7680 x 3840).
The real bottlenecks for viewing high resolution 360 videos are: 1) the bandwidth for playback; 2) the processing power required to play the 360 video, which is of course dependent on which phone you have.
The bandwidth issue can be resolved by downloading the files into your phone. The processing power issue is more thorny. I tested several videos with various resolutions on two different phones using the Insta360 Player app. Here are the results:
Xiaomi Redmi Note4 (Snapdragon 625)
4K 2D 360 (3840 x 1920) = smooth
4K 3D 360 (3840 x 3840) = smooth
5K 2D 360 (5120 x 2560) = choppy
5K 3D 360 (5120 x 5120) = choppy
6K 2D 360 (6400 x 3200) = choppy
6K 3D 360 (6400 x 6400) = choppy
Samsung S8+ (Snapdragon 835)
4K 2D 360 (3840 x 1920) = smooth
4K 3D 360 (3840 x 3840) = smooth
5K 2D 360 (5120 x 2560) = smooth
5K 3D 360 (5120 x 5120) = choppy
6K 2D 360 (6400 x 3200) = choppy
6K 3D 360 (6400 x 6400) = choppy
One solution to this bottleneck is more efficient processing that only processes the portion of the video that you are looking at any given time. This is the approach used by Visbit, solving both the bandwidth and processing bottlenecks. With this method, they are able to STREAM 6K 360 video (i.e., the video is not stored on your phone). Even my ~$150 Redmi Note4 could view 6K 360 video smoothly this way. Here’s a screenshot:
You can see this and other high resolution 360 videos on your phone by downloading a free Visbit demo for Samsung Gear VR or Google Cardboard.
SUMMARY
No you do not need a phone with 4K screen to view a 4K video. A smartphone has sufficient resolution to display up to 8K resolution.
When it’s 360 vid, sure, but what about a 4K 180 video? How much resolution is on the screen then?
4k vr180 video is usually 1920 x 1920 or 1920 x 2160 per eye. But not all of that resolution is visible when viewing in VR. You’re still looking at only a portion of the total resolution, so it is well below the limit of modern smartphones.