Here is another highlight from Indiana Public Access Counselor’s opinion archive from April 20th, 2017 (17-INF-05) regarding the recording of public meetings:

It is my understanding in the Huntertown Town Hall there exists a sign that says, “No Audio or Video Recording without Express Permission.” No authority or other qualifiers are provided. You inquire whether this signage is appropriate for a public space.

[…]

Therefore, an express prohibition on recording in council chambers during a public meeting is a de facto violation of the Open Door Law. Reasonable restrictions – size or noise of cameras, flash photography, etc. – may apply, however, a local government unit cannot prevent an interested member of the public or media to record a meeting.

As for the legality of recording in any other space or area outside of a public meeting, this Office declines to make a determination.