Asus zenfone 9 video recording problem

Please tell us some basic information before asking for help:

  1. Model Name: Zenfone 9
  2. Firmware Version: WW_32.2030.2030.26
  3. Rooted or not: NOT
  4. Frequency of Occurrence: always
  5. APP Name & APP Version (If your issue relates to the app): built in camera/video application

In addition to information above, please also provide as much details as you can, e.g., using scenario, what troubleshooting you've already done, screenshot, etc.

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Hello

I have a problem during recording a videos only in 60FPS mode (FHD/4k). I can observe a strange blinking - black vertical stripes (similar while you recording a monitor screen by another phone than you can see refresh stripes but this is vertical not horizontal.

It is occurring before I start to record (on the screen), during recording and after while I'm playing a recorded video. it only disappearing when I'm moving my phone, when I'm trying to keep it steady then it happening.

I tried to change recording codec h264 or h265 but it is the same.


Does anybody have same bad experience

about that.

Some files attached where you can see this effect.

Comments

  • Hi!

    It looks like what you are experiencing there is a very common effect of LED lights and cameras not having the same refresh rate.

    This is called LED Flicker and it's an issue that has been around for decades, it's also why you almost couldn't film a CRT TV back in the day.

    Does this happen in normal daylight? or only inside of the house?

  • Thank you for your reply, so far only inside of accommodation.

  • pawbetpawbet Level 1
    edited September 16

    And BTW I was writing about those refresh if crt tv but in crt tv you have horizontal stripes not vertical and that was strange so it is looks like not the same issue.

  • Because you have 2 very different usecases here. The CRT has horizontal stripes because it builts its image that way, It takes a line and very quickly generates the image from top to bottom, here is an example on slow motion:

    This is why you see horizontal stripes when trying to film a CRT, which is difficult to do.

    to elaborate on @Mattias_ASUS answer to what is happening and fix his CRT statement as it's not entirely comparible to what is happening hence I'd like to post this quote:

    Most phone cameras use what is known as a "rolling shutter", the exposure starts and ends at slightly different times for different parts of the image. This makes the sensor cheaper because the end of the exposure can be defined by the readout process rather than needing extra electronics to capture the image at the end of the exposure.

    This causes time-variations in the lighting level to be translated to spacial variations in the resulting image.

    So if your light source varies in intensity at a speed a few times faster than the sensor readout time, you will get bars like this. How dark the bars are will depend on the exposure time the camera is using. Pointing your camera directly at the problem light will likely result in a shorter exposure time and hence stronger bars.

    Many (but not all) flourescent and LED lights flicker at twice mains frequency, which tends to be in the same ballpark as sensor readout times.

    As @pawbet said, these are actually 2 different usecases. And as you saw in your own video, the closer you get to your light source, the stronger the bars get.

    I hope you find this explanation satisfactory.

  • I have the exact same problem. Can't almost shoot any video if its not at 30fps. This happens also in WhatsApp and Instagram.

    WW_32_2030_2030.26.

  • To elaborate: problem happens only with SOME interior lights. So I can confirm it's some sort of refresh problem. But I've tried filming the same lights with two other very different phones (iphone 13 and moto g41) and neither of them had this problem! I hope it can get fixed with future updates. It's really annoying since no videos can be shot in Instagram or WhatsApp with this problem. Or in 60fps mode with the camera app.

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