Blackmagic Forum

iPhone 15 Pro
Blackmagic Camera App: 1.3.00111
iOS 17.4.1

Quick test simulates reportage (and some travel) use cases, as experienced in numerous real life situations before giving up on the App, where the use of IEEE Float audio was not mandated.

Settings: ProRES 422HQ, HDR/HLG, 25 fps.

Apple Camera App and BlackMagic Camera App compared in same conditions, handheld and for Blackmagic Camera stabilisation is set to cinema to resemble Apple Camera standard settings.



Suffice to say, that both sound and sync takes a very heavy hit, when switching lens on the iPhone in Blackmagic Camera App compared to Apple Camera App in exactly the same conditions. An especially big problem for reportage (and some travel) use, where you cannot in any way predict lens needs from second to second. The - ahem - "side effect" of Blackmagics approach was present in the previous version 1.2.10003 too and reported.

Regards

Why does lens switch cause audio drop out

The reports of unwanted “None”-states in Audio settings periodically turning up in recordings, and involuntarily leading to no audio being recorded lead me to do a simple “drop out test”, when a Bluetooth headphone was removed.

See:https://forum.blackmagicdesign.com/viewtopic.php?f=2&t=196531#p1041677

It did not lead to “None” being activated, but it indicated, that anything involving the audio interface may inadvertendly affect the recorded audio on a non-involved interface. Still an - ahem - somewhat plausible outcome, but…

Can - does - non-audio operations - like lens switching - affect the audio interface and recorded content in any way?

I made an inspection of the lens switching MOV files, published earlier to show the heavy influence on visuals, when switching lenses (as indicated by the sudden drop in fps valiues), so why not look at the example recordings from another - ahem - “angle”; and I did:



And switching back again



Lens switch from “24” to “48” and back (file “A001_04091019_C003.MOV”) certainly affects the audio circuit. There is a complete audio drop out, as indicated. The file had only “ambient noise” recorded, but “Normalization” makes the drop out clearly visible as well as audible.

In this case, there is not even an actual lens switch involved, just a command to the iPhone to switch "zoom/crop" settings for the main lens. Should that simple operation affect audio in any way?

Here a comparison to the Apple file “IMG_7010.mov”, where there are no dropouts at all (just slight “touch” side-effects visible in the heavily amplified ambience noise):



I will leave it to anyone interested to check the effect by themselves. It’s easily done within a few seconds.

The original files (7.66 GByte) from "then" (April 9, 2024, not recorded with drop-out tests in mind) will be made available by a link on request (personal message, not in forum). All produced handheld, just to establish real-life possible run-and-gun or travel situations as background to the original).

Hmmm….

Now, the question suddenly becomes: is it possible to affect audio in other non—obvious ways or even - inadvertently - activate “None”, in a quick succession multi-take run-and-gun situation; maybe the user getting slightly jittery, while activating a lens switch or another, completely audio-non-related user interface screen “touch” operation?

Maybe, just maybe, there is a more or less general non-optimal user interface side effect in the Blackmagic Camera App user interface, that may lead to unforeseen and non-obvious “after effects”. Like missing audio in following parts of a recording, or in one, several or all following takes for one reason or other?

Lens switching clearly affects (mutes) audio recording in BMC 1.3.00111, which is not the case in any other tested Camera App. Example: Apple Camerra App, that does not exhibit ANY dropouts.

Regards