# Cell phone video three panels

**URL:** <https://boards.straightdope.com/t/cell-phone-video-three-panels/960546>\
**Category:** Factual Questions\
**Created:** [March 6, 2022, 3:05am UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546 "2022-03-06T03:05:36Z")\
**Posts on this page:** 20\
**Page:** 2

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**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\
**Post date:** [March 6, 2022, 7:22pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/21 "2022-03-06T19:22:31Z")

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> [@Mangetout](#):
>
> I understood it. I think it’s a bit of an opaque and technical way to talk about the change to the practical field of view that will be experienced by the camera user.

It’s also incorrect, if I understand it correctly.

> [@Darren\_Garrison](#):
>
> I said “What you do get is what is a true optical zoom in the framing.” You just didn’t understand that statement.

It’s not “true” optical zoom unless there is a zoom lens or a different lens. If it’s happening in software, it’s not optical zoom.

Maybe you meant that a 4000 pixel capable sensor can do an enlarged image with cropped top/bottom that still ends up 1920x1280.

If so, that’s not optical zooming.

> [@Darren\_Garrison](#):
>
> Horizon doesn’t sample across the sensor but picks 1920 “real” pixels from the center of the sensor and outputs those.

Which is what I can do in Premiere Pro when I have a 4k image I want to zoom into and crop off the top and bottom. I pick "1920 “real” pixels from the center and output them in my final edit.

That’s a software-caused enlargement with loss of information. It’s not an optical zoom.

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**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\
**Post date:** [March 6, 2022, 7:27pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/22 "2022-03-06T19:27:30Z")

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> [@I\_Love\_Me\_Vol.I](#):
>
> Maybe you meant that a 4000 pixel capable sensor can do an enlarged image with cropped sides that still ends up 1920x1280.

Yes, it is a real closer image with real, uninterpolated pixels, unlike software zoom on still photos. But I think that you understood what I meant, and wanted to be pedantic.

[![](https://i.kym-cdn.com/photos/images/facebook/000/909/991/48c.jpg) ](https://i.kym-cdn.com/photos/images/facebook/000/909/991/48c.jpg)

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**Author:** ![pjd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pjd/32/3009_2.png) [@pjd](https://boards.straightdope.com/u/pjd)\
**Post date:** [March 6, 2022, 7:30pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/23 "2022-03-06T19:30:39Z")

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This.  
I’ve often wondered. It’s annoying.

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**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\
**Post date:** [March 6, 2022, 7:31pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/24 "2022-03-06T19:31:14Z")

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> [@I\_Love\_Me\_Vol.I](#):
>
> Which is what I can do in Premiere Pro when I have a 4k image I want to zoom into and crop of the top and bottom.

Which is absolutely, positively, completely 100% irrelevant to the very point of the software, which is to allow horizontal video capture no matter the orientation of the phone.

> [@I\_Love\_Me\_Vol.I](#):
>
> That’s a software-caused enlargement with loss of information.

No, it is not.

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<div class="post-metadata">

**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\
**Post date:** [March 6, 2022, 7:39pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/25 "2022-03-06T19:39:56Z")

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> [@Darren\_Garrison](#):
>
> Which is absolutely, positively, completely 100% irrelevant to the very point of the software, which is to allow horizontal video capture no matter the orientation of the phone

Which is what I am doing when I zoom and crop my 4k vertical video into 1920x1280 horizontal.

We were not discussing the point of the software. We were discussing “true optical zoom” and how this app does not provide it. This is relevant.

I suppose that’s a nifty consumer treat for those genetically incapable of shooting things in a horizontal orientation. And it saves me about 30 seconds of work cropping and zooming their video when I have to use amateur video.

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**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\
**Post date:** [March 6, 2022, 8:03pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/26 "2022-03-06T20:03:26Z")

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I suppose the advantages of doing that cropping onboard the camera are:

- you only store the cropped frame, rather than storing 4K and cropping out of it later in the edit
- you are more likely to frame the shot properly if the app is showing you the already-cropped view on the screen as you record

And maybe there could be some compression-related advantage, but not sure on that.

Edit: just thought of one more thing - if you have a camera that has a reduced frame capture rate for 4K video, then cropping to HD on the device probably maintains the higher rate.

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**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\
**Post date:** [March 6, 2022, 8:07pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/27 "2022-03-06T20:07:45Z")

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> [@I\_Love\_Me\_Vol.I](#):
>
> I suppose that’s a nifty consumer treat for those generically incapable of shooting things in a horizontal orientation.

Or a nice option (note that I said “option”, as in an extra menu item that would be available in the software—not something always turned on) for anyone who wanted to use it.

Here is video capture of the app in action. The darkened area is the full 3,072 pixel width of the sensor, the light area is the “rotation safe” area.

[![](https://img.youtube.com/vi/KlVgf0weFCI/hqdefault.jpg "Hoizon sample") ](https://www.youtube.com/watch?v=KlVgf0weFCI)

Looking at it closely, it doesn’t just grab an exact square of 1920x1080 pixels, it grabs an area that _just_ fits the vertical resolution of the sensor when the video frame is touching it diagonally. So the video area has a diagonal dimension of around 1,536 pixels in my case instead of the 2,202 you get from 1,920x1,080. So you need more than a 12 MP sensor to avoid resampling.

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<div class="post-metadata">

**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\
**Post date:** [March 6, 2022, 8:15pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/28 "2022-03-06T20:15:29Z")

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> [@Mangetout](#):
>
> I suppose the advantages of doing that cropping onboard the camera are:
> 
> - you only store the cropped frame, rather than storing 4K and cropping out of it later in the edit
> - you are more likely to frame the shot properly if the app is showing you the already-cropped view on the screen as you record
> 
> And maybe there could be some compression-related advantage, but not sure on that.

Yeah. It’s a neat trick. It’ll makes things easier for many folks and with 4k cameras in mobiles now it’s not a crippling loss of information.

> [@Mangetout](#):
>
> Edit: just thought of one more thing - if you have a camera that has a reduced frame capture rate for 4K video, then cropping to HD on the device probably maintains the higher rate.

I wonder about that. Hmm. I haven’t thought this through all the way… If this is an app, and not a feature of the camera itself then isn’t it probably just using the 4k image and turning it post image capture?

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<div class="post-metadata">

**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\
**Post date:** [March 6, 2022, 8:18pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/29 "2022-03-06T20:18:35Z")

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I think it probably depends on a lot of small technical details, but an app that is showing you the cropped frame within the wider full-sensor view, is probably not going to be able to lay down that cropped portion at the higher framerate, whereas an app that is only polling the cropped portion of the sensor probably could.

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<div class="post-metadata">

**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\
**Post date:** [March 6, 2022, 8:19pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/30 "2022-03-06T20:19:19Z")

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> [@Mangetout](#):
>
> I suppose the advantages of doing that cropping onboard the camera are

I think there is a misunderstanding what the software does. It isn’t a horizontal/vertical binary, it is a dynamic rotation that keeps the image being recorded horizontal no matter how the phone is rotated (as can be seen in my sample.)

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<div class="post-metadata">

**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\
**Post date:** [March 6, 2022, 8:20pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/31 "2022-03-06T20:20:31Z")

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> [@Darren\_Garrison](#):
>
> I think there is a misunderstanding what the software does. It isn’t a horizontal/vertical binary, it is a dynamic rotation that keeps the image being recorded horizontal no matter how the phone is rotated (as can be seen in my sample.)

Well, that’s still a crop.

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<div class="post-metadata">

**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\
**Post date:** [March 6, 2022, 8:22pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/32 "2022-03-06T20:22:51Z")

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> [@I\_Love\_Me\_Vol.I](#):
>
> Well, that’s still a crop.

Excellent job punching that straw man. You know, the one who was claiming that it isn’t a crop? Because that certainly wasn’t me. Once again, in my original reply to Chronos I explicitly stated that it changes the framing.

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<div class="post-metadata">

**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\
**Post date:** [March 6, 2022, 8:40pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/33 "2022-03-06T20:40:22Z")

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Sorry, I was called away. I wasn’t done with my post yet.

> [@Darren\_Garrison](#):
>
> I think there is a misunderstanding what the software does. It isn’t a horizontal/vertical binary, it is a dynamic rotation that keeps the image being recorded horizontal no matter how the phone is rotated (as can be seen in my sample.)

Well, that’s still a crop.

I think you could call it “dynamic rotation” in a way but partly it’s a bit of an viewfinder illusion. It’s likely all done in the (in-camera) post-processing . It’s not like there is a little gimbal inside the camera that is perfectly rotating the sensor to counteract the phone’s rotation.

IOW, the camera is recording a video at it’s highest resolution (4k with some phones) but before output it’s cropped down to the rectangle zone you saw highlighted in the viewfinder and the rest of the info is discarded. The resolution of the output image is then probably one spot lower-res from the camera’s max video resolution (e.g. 4k → 1080; 1080–\>720; 720 → 480, etc.).

Because this app likely has a “speed penalty” (effectively needs more light to get the same ISO) there will be other sub-optimal constraints like lower framers-per-second and lesser color and luma data.

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<div class="post-metadata">

**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\
**Post date:** [March 6, 2022, 8:42pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/34 "2022-03-06T20:42:20Z")

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> [@I\_Love\_Me\_Vol.I](#):
>
> Because this app likely has a “speed penalty”

The more I think about it it might not necessarily have any speed penalty.

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**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\
**Post date:** [March 6, 2022, 8:45pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/35 "2022-03-06T20:45:32Z")

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Another way to put it is that it DOES involve loss of a lot of information, but the default video-recording app on most cameras also involves the same amount of loss of information, just because nobody wants several-thousand-pixel-wide videos.

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**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\
**Post date:** [March 6, 2022, 8:54pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/36 "2022-03-06T20:54:19Z")

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> [@I\_Love\_Me\_Vol.I](#):
>
> I think you could call it “dynamic rotation” in a way but partly it’s a bit of an viewfinder illusion.

I meant the possibility that it was thought that the software simply crops an image at vertical (call it 90 degrees) to be a video at horizontal (call it 0 degrees) in a simple binary. But it rotates 17 degrees, 23 degrees, 48 degrees, 77 degrees, etc. and updates moment-by-moment.

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**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\
**Post date:** [March 6, 2022, 9:08pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/37 "2022-03-06T21:08:50Z")

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If the crop is not orthogonal to the sensor, then it’s not just a crop - it’s resampling before writing the output video. That’s quite likely to incur some loss of fidelity even if the output image size does geometrically fit within the pixel width of the sensor.

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<div class="post-metadata">

**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\
**Post date:** [March 6, 2022, 10:41pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/38 "2022-03-06T22:41:49Z")

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There are some fast, simple rotation algorithms where every pixel of the output corresponds exactly to a pixel of the input. I’m not sure if that would be what you’re counting as a “resampling”.

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<div class="post-metadata">

**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\
**Post date:** [March 6, 2022, 11:00pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/39 "2022-03-06T23:00:44Z")

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I’m struggling to comprehend how that is possible for rotations that are not 90 degrees or a multiple

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<div class="post-metadata">

**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\
**Post date:** [March 6, 2022, 11:16pm UTC](https://boards.straightdope.com/t/cell-phone-video-three-panels/960546/40 "2022-03-06T23:16:32Z")

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For example, assuming the below is an image 2 pixels by 2 pixels, and you are permitted to expand the canvas to accommodate the rotation, how will it appear when rotated through any angle that is not a multiple of 90 degrees?

[![](https://upload.wikimedia.org/wikipedia/commons/thumb/5/5f/Checkerboard_tile.svg/1024px-Checkerboard_tile.svg.png) ](https://upload.wikimedia.org/wikipedia/commons/thumb/5/5f/Checkerboard_tile.svg/1024px-Checkerboard_tile.svg.png)

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