For a photon, $$E = pc$$ from the Einstein Energy Equation. Or $$E = hf$$ with $$p = hf/c$$
From the Heisenberg uncertainty principle $$(\Delta x)*(\Delta p) = h/2$$ The maximum value for $\Delta p$ for real values of momentum and also for imaginary cases (I think I didn't really find the maximum of the function using calculus) is $2hf/c$ as the photon can either be going straight up or straight down. Then the minimum value for $\Delta x$ is $c/(4f)$ ... so as frequency increases, one can determine the position to arbitrary large amounts, but at a fixed frequency there will be a uncertainty of $c/(4f)$.
I am not sure if this is true or can be determined by experiment, or if this relation breaks down at large frequencies. It would be interesting to see what happens in an experiment with extremely high frequency (Energy photons and seeing how small $\Delta x$ became, and saw if it tends to follow this relation)