Why does Apple not specify the frame rate (29,97 fps) of the front camera of iPhone?

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Level 1

8 points

Why does Apple not specify the frame rate (29,97 fps) of the front camera of iPhone?

Why does Apple - or anyone else for that matter - not tell that the front facing camera of iPhone 7 (and perhaps other models as well) use 29,97 fps (frames per second) as opposed the rear camera that uses 30 or 60 fps? Is it a secret? Is it sloppiness? Is it a mistake?

Whatever the reason, it is a fact - and a strange one - that the front facing camera always records at 29,97 frames per second.

It does not matter whether you change the camera settings. They only apply to the rear camera. There is no way, you can change the frame rate of the front camera.

The rear camera can change between several frame rates, e.g. 30 or 60 fps, however not 29,97 fps.

So the front and rear cameras can never record movies at the same frame rate.

I think, this is very important information to be aware of as a customer, especially when the cameras hold a pretty good standard that may be used even professionally.

It is problematic, if you have to use the audio or the lip movements from the recordings, e.g in a music video, and some footage is from the rear and some from the front camera, because it is complicated to sync them or to convert them.

It took me quite a long time to discover that they use different frame rates. Not even the well informed Wikipedia reveals the 29,97 fps on the front camera. Neither does Apple, as far as I know. Nor could I find any tutorials or the like on YouTube about it.

I simply do not understand why Apple does not specify it anywhere. There is nothing wrong with different frame rates. We just wanna be aware of it.

And it would be nice, if you could set the frame rates for both cameras or, at least, that they shared one of the frame rates.

I know that the front camera is not meant for recording videos, but it is actually pretty good, and it has a great advantage, because you can simultaneously monitor on the screen what you record.

Dear Apple, please give my input some consideration for future iPhones (if you have not done so already - I only have an iPhone 7).

iPhone 7, iOS 11

Posted on May 9, 2020 6:21 PM

Reply

Answer 1

May 10, 2020 4:14 AM in response to HrSvanholm

FWIW, I used Filmic Pro on my iPhone 7, and it is able to record in many more different frame rates than the standard Camera app - besides many more features.

I use 25 fps since I live in Portugal, and that is the usual frame rate on this side of the pond.

I just tried to record in 25fps using the front camera, and it did.

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Answer 2

Tom Wolsky

Level 10

152,929 points

May 10, 2020 5:08 AM in response to HrSvanholm

You don't have to convert every file. It depends on what you need to do. If you need to sync files are the thread seems to imply, then yes, you should convert the files both to a specific frame rate and also to the video standard audio sample rate of 48K.

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Answer 3

May 10, 2020 4:21 AM in response to HrSvanholm

Like I said, not in the Camera app.

I use a third party App, Filmic Pro:

https://apps.apple.com/us/app/filmic-pro-video-camera/id436577167

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Answer 4

Tom Wolsky

Level 10

152,929 points

May 9, 2020 6:26 PM in response to HrSvanholm

This is a user to user forum. You would need to use feedback to make a feature request.

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Answer 5

Tom Wolsky

Level 10

152,929 points

May 9, 2020 6:34 PM in response to HrSvanholm

For FCP it’s in the Final Cut Pero menu. Btw current phones record in the selected frame rate in both front and back cameras. I think this is actually a software setting, and it’s not very good as the frame rate is not accurate and varies quite a bit.

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Answer 6

MrHoffman

Level 10

158,473 points

May 9, 2020 6:34 PM in response to HrSvanholm

HrSvanholm wrote:

BTW: Where do I post feedbacks?

Product Feedback - Apple

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Answer 7

Tom Wolsky

Level 10

152,929 points

May 10, 2020 4:47 AM in response to HrSvanholm

It’s the variable frame rate problem. The frame rate is supposed to be 30. That’s why it’s identified as 30.

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Answer 8

HrSvanholm Author

Level 1

8 points

May 10, 2020 4:11 AM in response to Tom Wolsky

I just upgrade to 13.4.1, and the issue remains.

Furthermore, there seems to be another issue. The frame rate is calculated differently. In Quicktime, the frame rate of an iPhone 7 front camera recording is calculated as 29,98 fps, but in Final Cut the frame rate of the same recordingis calculated as 30 fps.

The frame rate of an iPhone 7 rear camera recording is calculated as 30 fps in both Quicktime and Final Cut.

It is Final Cut that calculates wrong, because the audio lag is a fact, so the frame rates must be wrong.

So now, we are at two mysteries:

Why does apple not inform about the different Fram rates of the cameras?

Why does Final Cut calculate wrongly?

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Answer 9

HrSvanholm Author

Level 1

8 points

May 10, 2020 4:19 AM in response to Luis Sequeira1

I am from Denmark, so it is the same side of the pond, but I wonder: How did you switch to 25 fps? Where did you find that option? I can only choose between 30, 60, 120 and 240 fps. The latter two only for slowmotion. They all only apply for the rear camera. There are no specific settings for the front camera.

So how did you pull that off?

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Answer 10

HrSvanholm Author

Level 1

8 points

May 10, 2020 5:04 AM in response to Tom Wolsky

"Variable frame rate", that was a new concept for me. I just read a little about it. That is a frustrating issue, for this means that you would have to convert every recording fra om your iPhone to a constant frame rate before editing, right?

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