This study focuses on the characterisation of downwards annular gas-liquid (air-water) flows, by employing a combi-nation of advanced laser-based and capacitance-based measurement methods. A variant of laser-induced fluorescence(LIF), referred to as structured-planar laser-induced fluorescence (S-PLIF), eliminates biases commonly encounteredduring film-thickness measurements of gas-liquid flows, due to refraction and reflection of the light at the interface. Abespoke capacitance probe is also assembled to enable temporally resolved film-thickness measurements with high tem-poral resolution along the circumferential perimeter of the pipe. We compare the film mean thickness, roughness, andprobability density functions obtained with each method. We find that both methods are able to measure time-averagedfilm thickness to within<20% deviations from each other and from results obtained from the available literature. Theresulting probe data suggest a biased (suppressed) standard deviation of the film thickness, which can be attributed toits working principle, i.e., measuring the film thickness averaged along the circumferential perimeter of the pipe. Theauto-correlation functions of the time-traces provide an insight into the characteristic time-scales of the flows, whichspan a range from∼10 ms for highly gas-sheared flows and increase to about 30 ms for the less turbulent falling films.The power spectral densities reveal modal frequencies that start from 2.5 Hz for falling films, and increase with the gasReynolds number by almost an order of magnitude. The turbulent wave activity (slope in the power spectrum) reduceswith a decrease in gas shear, and shows similarities to the decay of homogeneous and isotropic turbulence. The sizes ofthe bubbles entrained in the liquid film are measured from the S-PLIF images, and exhibit log-normal distribution thatbecome flatter with a decrease in the gas Reynolds number. The normalised location of the bubbles (quantified as therelative entrainment depth, i.e., distance of the bubble from the wall over the local film thickness) follows a Gaussiandistribution, with the peaks located between 0.5 and 0.6, indicating that the majority of the bubbles accumulate in themiddle of the thin film.