Try this project code If you want to take multiple Images without dismissing the view using UIImagePickerController source type Camera.
In this project I set showsCameraControls variable to false so that I will hide native camera controls and we can add our custom controlls to handle different camera event such as takePicture, switch camera and many more.
Now I build custom view to set as a cameraOverlayView. In that view I added one UIButton and on click of it, It will call UIImagePickerController's takePicture method. It will give taken image in delegate method and will be ready to take new image without dismissing the view.
Here is the screen recodring of the final result: