Trasparency on background

Is there a way to have the background transparent, in order to use it with atem mini as secondary screen?

could it be added as option in display settings?

The easiest way to do this is by using the Chroma or Luma capabilities of the ATEM Mini. We have used this for a couple of years to overlay the words of the songs onto the output from our video camera. Think of the words as being foreground and the video as background. The difference between the two is:

Chroma uses one colour on the foreground stream (optionally with a degree of variation) and makes that transparent so that the background shows through. This is frequently known as "Green screen", although it can be used with any colour. Use the settings in the Atem to select the colour and how much it can vary from the exact match.

Luma uses the contrast between dark areas and light areas on the foreground display. The dark areas are made transparent, to show the background behind what is left.

Luma works well with high contrast inputs, such as white words on a black background, as you get from Presenter. Chroma is more suited to when the foreground is more pictorial, with more colours and less contrast between the areas you want transparent and the areas you want to keep.

We also found that, by careful tuning of the variability of the Luma or Chroma settings, matched with a template with a 50% transparent grey area where the text shows, we can make the text appear on a mid-grey, semi-transparent panel, which helps the clarity significantly. You can see this in any of the service recordings on our website, https://leambaptist.uk/services/ or facebook page, https://www.facebook.com/LeamBaptist