Photographs and bats (yes, bats)...

[koti]

1 hour ago, CharonY said:

But why would you expect brightness differences if the focus motor is distorted?

The ultrasonic waves emitted by the bat increase the resonsnce of the motor which in effect cause the surface of the camera sensor to vibrate causing banding in in the specific region. Now tell me there is zero chance of this happening  

[CharonY]

Not sure how, that would work, either. First, I am not sure how, say, vibrations in the focus motor would shift the sensor. While there are sensors that allow shifting (e.g. for stabilization), they move laterally, so it should not affect brightness. If the sensor is able to move all the way out of the light path, you probably have a defective camera. Either way, the first thing you get is a blurry mess. There may be a way to create brightness artifacts, but I cannot think of  way to create such pronounced ones.

[koti]

31 minutes ago, CharonY said:

Not sure how, that would work, either. First, I am not sure how, say, vibrations in the focus motor would shift the sensor. While there are sensors that allow shifting (e.g. for stabilization), they move laterally, so it should not affect brightness. If the sensor is able to move all the way out of the light path, you probably have a defective camera. Either way, the first thing you get is a blurry mess. There may be a way to create brightness artifacts, but I cannot think of  way to create such pronounced ones.

Me too.

[CharonY]

Perhaps pulsing the sensor back and forth (rather than lateral) but at frequencies relative to the readout speed. 

[koti]

40 minutes ago, CharonY said:

Perhaps pulsing the sensor back and forth (rather than lateral) but at frequencies relative to the readout speed. 

Maybe a capacitor giving wrong voltage in the low pass filter but that would have to be a bery powerful ultrasonic wave pulse certainly not possible for a bat. Your banding explanation is very plausible on the other hand, in fact you can see live view flicker on some of the older phones due to 50/60hz.

Edited April 2, 2018 by koti

[Bender]

I was just watching some videos I made earlier on my phone and clearly noticed banding in one of them. Curious how I never noticed it before. Serenidipity is great.