Black border in Black Magic

[RTR Joe]

 Hi Guys I am new to the TV stuff but I'm in with both feet now , I bought a Black Magic stem pro iOS nice piece , but I need cameras for my studio , I have 2 T5 Canons and a T3 Canon all have HDMI out which is great , I installed Magic Lantern on all 3 no problem but I have one issue and I'm hoping it's a setting . All 3 camera are set on video on tripods and the picture we get is HD no problem but it has a black box around it , I have tried everything to get rid of them . If I plug my iPhone in as as a camera it's the full screen like it should be .
Can anyone guide me on how to fix this ? Just one other little issue is randomly the camera's click off and the click back on a couple seconds later . I have the camera's set to never shut off . Any tips ? Thanks a million . You can see the show on YouTube @RacetimeradioTV
Any help would be appreciated. I'm new to TV versed in radio !

[dpjpandone]

you can't get rid of the black box, you have to crop the hdmi feed with your streaming software to make it full screen

[RTR Joe]

Are you familiar with the Black Magic switcher by chance ? Where would I look on it ?
Thanks so much !

[dpjpandone]

Are you familiar with the Black Magic switcher by chance ? Where would I look on it ?
Thanks so much !

they make several, which one? 4 channel atem mini?

[dpjpandone]

looks like you can zoom in until the black bars extend off the screen (disappear)