These pictures were taken Sat morning with overhead clouds at Pescadero Marsh with the Sony A1, 600/F4 and 1.4x. In-flight images were taken hand-held, but due to the bulk and weight, not as many images were shot as those with the Olympus 150-400 rig, see this link

Royal tern warning a seagull, 1/1000, F6.3, iso2500, 840mm

100% crop, 1/1250, F5.6, iso1600, 840mm

100% crop, Northern Harrier, 1/3200, F5.6, iso10000, 840mm

1/3200, F5.6, iso2000, 840mm

Common merganser, 1/3200, F5.6, iso2000, 840mm. Not a particularly attractive shot, but it illustrates the bokeh of the 600/F4 lens.