I have a loop: for(int i = 0; i < N; i*=5) {...}
where {...}
is some statement.
I’m trying to understand its run time. So, far I know that:

We start with $ i = 0$

We finish when $ i = n1$

$ i$ is incremented by being multiplied by 5 = $ i^5$
So, would the runtime be $ \log_5(n1)$ ? The reason I’m not sure it’s because I thought when analyzing algorithms we had to use base 2 log functions. If the latter is the case how would I got about converting $ \log_5$ to $ \log_2$ ?