Before Apple's making the EIS (Electronic Image Stabilisation) dis/enable switch user-accessible (in the video formats menu - see "Camera > Record Video > Enhanced Stabilisation"), the iPhone cameras' video mode has ALWAYS somewhat reduced the visible area. Therefore, now that we have a switch, it's great you no longer need to use third-party apps to have as many effective pixels in your video as possible. Back then, that was the only way of making use the sensor pixels allocated for stabilization. I even published the source code of my iPhone app allowing for EIS-less shooting. Back then, during the iPhone 5 times (which doesn't have optical image stabilization (OIS for short)), when EIS used a lot more pixels than today (when the current models all have OIS), it was useful to disable EIS when shooting from a tripod. The old models all had comparatively narrow lens, and videoing made them even narrower.)
I've played with this switch a bit and found out the following:
1, no effect on the ultra wideangle (UWA for short) lens, only on the two others. That is, you can't make the UWA lens "see more" in video mode by disabling the switch, unlike with the two other lenses.
2, even with the switch disabled, NOT the entire sensor's width is used for the video. The reason for this isn't rock science: the sensor is 4032(x2) wide, while the 14 "only" records 3840x2160 4k (4K UHD) videos, not anything higher. Actually, it couldn't record the 4096 × 2160 (DCI 4K) as the sensor is narrower than 4096 pixels even if it wanted to.
This, BTW, also means there is a 1:1 pixel-to-video mapping, and not any kind of supersampling from the entire width (all pixels) of the sensor.
BTW, I also checked whether enabling (which is default) the "Lens correction" switch results in the UWA lens' image getting narrower. Nope - that is, you can't make it wider by disabling the switch.
I've played with this switch a bit and found out the following:
1, no effect on the ultra wideangle (UWA for short) lens, only on the two others. That is, you can't make the UWA lens "see more" in video mode by disabling the switch, unlike with the two other lenses.
2, even with the switch disabled, NOT the entire sensor's width is used for the video. The reason for this isn't rock science: the sensor is 4032(x2) wide, while the 14 "only" records 3840x2160 4k (4K UHD) videos, not anything higher. Actually, it couldn't record the 4096 × 2160 (DCI 4K) as the sensor is narrower than 4096 pixels even if it wanted to.
This, BTW, also means there is a 1:1 pixel-to-video mapping, and not any kind of supersampling from the entire width (all pixels) of the sensor.
BTW, I also checked whether enabling (which is default) the "Lens correction" switch results in the UWA lens' image getting narrower. Nope - that is, you can't make it wider by disabling the switch.
