Since two weeks, I'm having problems with zoom, with the video. I don't really understand what's happening, I've never had these issues before. My image is shaky, freezing, it's very hard to describe actually and I'm not sure if anyone had the same problem.I do'nt think it's the webcam or PC issue, because 1) I've tried to uninstall and install again 2) I've logged with a different account 3) I used Zoom on a different PC. Everytime this problem occurs. 
I'm attaching a screenshot, it visualizes the problem better. 
Please any tips, help would be greatly appreciated! Thanks.

I use an Apple Mac. Whenever (like today) a new Zoom update is automatically download to my Mac, I lose a lot of Zoom settings. Like pictures for virtual backgrounds. I lose the standard pictures provided by Zoom and my personal pictures. For my pictures, I have to download them again after each update. For the Zoom pictures, I need to shut down my computer then the Zoom pictures are reloaded. I also will at times lose some settings on my Nexigo 950P camera, external mic. Are there any settings in Zoom that I'm missing that will keep my background pictures and other settings?

Hello I am looking at how to record business meetings on a budget. I am looking at the use of an iPhone and utilising Zoom software. An area I am trying to find the best solution for is, what microphone would be best for the audio. I don’t want to go to the expense of wireless, rather just the best iPhone compatible microphone to reach distances of up to 30 feet.

I noticed that I have what is essentially a black frame around my video, so my image looks smaller than other participants in the same meetings.  I am connecting using a Nikon SLR camera and believe it is related to my camera settings.  Does anyone know how to adjust this?