A VR video file tells you three separate things, and they are easy to confuse with each other. It has a field of view — how much of a sphere the camera captured. It has a stereo layout — whether there are two eye images, and how they are packed into a single rectangular frame. And it has pixel dimensions, the number people quote when they say "8K VR".
Those three are independent. A file can be 180-degree, side-by-side, and 8K; or 360-degree, monoscopic, and 4K. Almost every "my VR video looks broken" complaint is a player applying the wrong assumption about one of the three.
What is the difference between 180 and 360 degrees?
Field of view is how much of the sphere around the camera was recorded, and 180 degrees dominates this material for one practical reason: it spends every pixel where you are actually looking.
A 360 camera records the full sphere; a 180 camera records the hemisphere in front of it. At the same pixel budget, the 360 file stretches those pixels over roughly four times the surface area, so any given part of the image gets a quarter of the detail. What you gain is the ability to look behind you — at a wall, a lighting rig, and a tripod.
For camera-facing content that trade is one-sided: 180 concentrates resolution on the part of the sphere that was composed to be looked at. Hence the common label VR180.
How are two eye images packed into one file?
Stereoscopic video needs two images, one per eye, but a video file holds one rectangular frame per timestamp. The two images are therefore packed inside that single frame, either side by side or one above the other.
- Side-by-side (SBS, sometimes
3dhfor "3D horizontal") — left eye in the left half of the frame, right eye in the right half. Each eye gets half the horizontal pixels. - Over-under (OU, sometimes
3dvfor "3D vertical") — left eye on top, right eye below. Each eye gets half the vertical pixels. - Monoscopic (
mono,2d) — one image, shown to both eyes. There is depth in the picture but no depth perception; it looks like a very large curved screen rather than a place you are standing in.
This is the most persistent misunderstanding about VR resolution. A file advertised as 7680×4320 side-by-side is not delivering 7680 pixels of width to each eye; it delivers roughly 3840 per eye, with the full 4320 of height. The headline number describes the container, not what reaches your retina.
What do the tags in the filename actually mean?
Filename tags are how a player usually decides what to do with the frame, since the information is often not reliably stored anywhere else.
| Tag you see | What it means | How it looks if the player guesses wrong |
|---|---|---|
_180 / _LR_180 |
180-degree hemisphere | Applied as 360: the scene wraps too far, and content is stretched sideways |
_360 / _TB_360 |
Full sphere | Applied as 180: you see only part of the scene, hugely magnified |
_sbs / _3dh / _LR |
Side-by-side stereo | Not applied: two narrow copies of the scene side by side |
_ou / _tb / _3dv |
Over-under stereo | Not applied: two squashed copies stacked vertically |
_mono / _2d |
Single image, no stereo | Applied as stereo: the frame is split and halves are shown to each eye, giving a cropped, mismatched view |
_fisheye / _190 / _200 |
Wider-than-hemisphere lens projection | Applied as standard equirectangular: straight lines bow, edges warp |
Some players also read projection metadata embedded in the container. There is more than one scheme for writing it. Google's Spherical Video V2 specification defines the boxes most 180 and 360 files carry — one for the stereo layout, one for the projection — with a separate VR180 specification layered on top. MPEG standardised its own omnidirectional media format as ISO/IEC 23090-2, now in its third edition. Apple has published container extensions of its own for stereo and projected video.
One structural point explains much of the inconsistency: Google's boxes are a de-facto convention rather than a registered part of the MP4 format. They do not appear in the official registry of container box types, where the stereo boxes defined by ISO and by Apple do. A player is therefore free to ignore them without being wrong, which is why the filename tag remains the more dependable signal in practice.
Sources: Google spatial-media Spherical Video V2 and VR180 specifications; ISO catalogue entry for ISO/IEC 23090-2:2023; MP4 Registration Authority box registry; Apple ISOBMFF stereo video format additions v1.0 (2025); checked 2026-08-03.
The practical consequence: renaming a file can break it. Strip _180_sbs
from the name and a player that relies on the tag falls back to a flat,
monoscopic guess.
Why does VR need such a high resolution to look merely acceptable?
Because what your eye judges is not pixels in the file — it is pixels per degree of your field of view, and a headset spreads the image across a very wide angle.
A flat screen occupies a narrow slice of your vision, so its pixels are packed densely into that slice. A headset lens magnifies the image across most of your field of view, spreading the same pixels far thinner. Add stereo packing halving the per-eye width, and equirectangular projection wasting pixels near the poles, and it is clear why VR files need dimensions that sound absurd for flat video.
The gap is large enough to be worth quantifying. Vendors that publish a field-of-view figure put current headsets between roughly 96 and 120 degrees horizontally — Meta gives 110° horizontal and 96° vertical for Quest 3 and 96°/90° for Quest 3S, Pico gives 105° for the 4 Ultra, Sony approximately 110° for PlayStation VR2, HTC up to 120° for Vive Focus Vision. Apple publishes no figure for Vision Pro at all. A flat screen viewed as intended occupies far less: ITU-R's optimal viewing angle is 32 degrees for 1080p and 58 degrees for 4K. The same pixels are being asked to cover something like two to three times the visual angle.
Sources: vendor specification pages (developers.meta.com, picoxr.com, playstation.com, vive.com, apple.com); Report ITU-R BT.2246-9 (2025), Table 1; checked 2026-08-03.
The arithmetic that matters:
- Start with the frame's stated width.
- Halve it for side-by-side stereo.
- Divide the remainder across the covered field of view.
A 7680-wide SBS 180 file gives about 3840 pixels per eye across 180 degrees. The same file in 360 would give the same 3840 across 360 degrees — half the angular density. That single step is the whole 180-versus-360 argument.
Which format should you actually look for?
Absent a strong reason otherwise, 180-degree stereo at the highest dimensions your device can decode smoothly — the default that goes wrong least often.
| What you want | Format to look for | Why |
|---|---|---|
| Best perceived sharpness | 180, stereo (SBS or OU), highest available dimensions | Pixels concentrated on the visible hemisphere |
| A sense of being present in a space | Stereo, any field of view | Depth perception comes from stereo, not from coverage |
| Ability to look all around the room | 360 | The only format that records behind the camera |
| Playback on a weaker device | Lower dimensions, 180, stereo | Decoding cost scales with pixel count, not field of view |
| Watching flat on a normal screen | Mono, or a player that can flatten a 180 file | Stereo files show as doubled images on a flat display |
How do you diagnose a VR file that looks wrong?
Each failure mode has a distinct signature pointing at one misapplied setting.
| What you see | What it means | Fix |
|---|---|---|
| Two copies of the scene, side by side | Stereo layout not applied | Set the player to SBS |
| Two copies stacked vertically | Stereo layout not applied | Set the player to over-under |
| A flat rectangle with bowed edges | Projection not applied | Set the projection to 180 or 360 equirectangular |
| Scene wraps too far around you | 180 file being played as 360 | Switch field of view to 180 |
| Extremely magnified, only part visible | 360 file being played as 180 | Switch field of view to 360 |
| No depth at all, image looks like a screen | Monoscopic source, or stereo mode off | Check the source file; mono cannot be recovered |
| Eyes feel misaligned, strain within minutes | Left/right halves swapped | Toggle the player's eye-swap option |
Work through them in that order — layout, then projection, then field of view. Changing two settings at once hides which one was wrong.
Related questions
- How do you choose a VR headset for adult content?
- Can you watch VR adult content on a phone?
- What do video resolutions from 480p to 8K actually mean?
- How do the VR platforms compare?
Format tags tell you what a file is, but not where to get it legitimately — our site directory lists the platforms we index.