Why there is no video output when recording 4K ? Hollyland Tech November 30, 2020 11:26 This is limited by DSLR/Mirrorless cameras. We suggest you use the mobile App to monitor the feed, or connect the camera to an ATOMOS monitor first, then output the feed to the device. Related articles UPGRADE why the audio and video are not synchronized？ How to set them up when multiple sets of MARS 400S are used at the same location? MARS 400S PRO RELEASE Hollyview APP Connection Comments 0 comments Article is closed for comments.