- Is it a static/low frequency magnetic field or a varying one?
- How strong is the field at the camera?
Typically electronic devices have a modest amount of EMI/RF shielding already, that and a stainless steel enclosure would handle modest levels of EMI. Some environments, like an MRI room though, need Faraday cage style protection.
You can get magnometer app on your phone and do some readings to find out approx how strong the field is.
1.It is not static as the site has varying magnetic field. We have 148 cameras in the field.
2.The values measured are 5.10 by -4 Tesla to 1.10 by -3 Tesla and also asked us there will be a 20% increase to be considered.
Hope this can give an idea and please advise
Good solid grounds on all housings, conduits, raceways.
Choke Coils on all lines from the cameras , and at the point of entry to the server .
If this does not fix the problem , the use isolation coils ( optical Isolators ) between camera and line side of feed to the server .
Most quality manufacturers have in place a reference for these procedures.