Not an issue with my gear but a question I have about modern camera technology:
I've been crawling all over the web trying to find a verified answer to this, but I've failed.
Using a high quality microphone, I recorded a DSLR (specifically the SL3) capturing photos. I noticed in the spectogram that there were two very distinct ultrasonic sounds being produced by the camera. One tone at exactly 20kHz and the other sound at 60k-70kHz. When I slowed this audio down to 10% of it's original speed so that I could hear the ultrasonic sounds, the 20kHz tone sounds basically just like a sine tone and the other 60k-70kHz sound is more like static/noise. I'm assuming from my research that these sounds are ultrasonic actuators/motors which are driving the mirror and shutter mechanisms. But I can't find any source which directly states whether there are ultrasonic actuators that drive DSLR mirror mechanisms. I know most lenses use ultrasonic focus motors, so I figure this is the same with the motors for the mirror and shutter mechanisms.
I also recorded a mirrorless camera (R5II) and it produces a similar "static" sound well into the ultrasonic frequency range (when using the mechanical shutter, of course).
Does anyone have any data on this?
