how do I input Log 4 and not Log 10
Do you mean how to change from base 10 to base 4 logs? If so, then this example will show you that: what is log 100 to base 4:
Log(100) / Log(4)=2/0.60206=3.32192. And that is log 100 to base 4, so that:
4^3.32192=~100
To enter log of 16 base 4
Log(16,4)
