In general, camcorders will give a better experience for live event streaming compared to using DSLR cameras.
The camera source used for a live event stream should offer a "clean" HDMI output, and this can be found on even consumer-level camcorders at a lower price point than most DSLR cameras.
DSLR cameras can have one or more of the following limitations:
- on screen display (OSD) text information may be visible on the HDMI output from the DSLR which cannot be disabled
- the video output over HDMI may be cropped, have a reduced resolution, or may have pillar box / letter box black bars present
- the built-in display on the DSLR may shut off when an external device is connected over HDMI
- analog audio input (to allow the use of external microphones) may not be present on the DSLR
- audio may not be present over HDMI output from the DSLR
- video may not be present over HDMI in all modes (e.g. preview, recording, playback)
There are many other forums and posts on external sites which discuss limitations on DSLR cameras such as overheating of the sensor, below is one such example: