My father was on H M C S Uganda in the pacific so I'm guessing that's the ship but I'm Really not sure...
Uganda was fitted with two quad 40mm in October 1944. scrounger's dad's photo is the port one, you can also see it in the 1944 photo in this link HMS Uganda - RN warships of WW2 . The 40mm is just aft of the bridge in the space designed to accommodate a cross-deck catapult; the original design also included aircraft hangars which is why the forward superstructure is so large and blocky. Aircraft were omitted from the last group of Colony class ships including Uganda. The photo appears to have been taken from the superstructure, near the forward funnel. The little tower just aft of the 40mm, or in the top left of dad's photo, is probably a director. Since this was not originally intended to be a gun position, the mount appears to have a relatively limited arc of fire. Uganda also had quad 2pdr pompoms in better positions on each side of the bridge and on the centerline aft. Thanks, scrounger - is your dad still with you?