The camera manual will tell you. Here in forum the recommendation goes about 45% maximum. There is no minimum setting, the myth about dry air damaging camera equipment has been busted.How many % actually the humidity should be in the dry cabinet? I am not sure also
There is no point being obsessed with 45% or 40% when the hygrometer is not accurate. So get a calibrated one or do the salt test to know how far your current hygrometer is off.