Watching the skies

Thought I'd have a go at taking some pics of Jupiter, which has been very bright this week - and nice crisp, cold, clear night tonight seemed a good time to do it. Pretty amazed that a 300mm cheapie Sigma lens performs well enough to show three of the four moons (assume the fourth is being coy behind Jupiter itself) All done on tripod with a remote release. Experimentation showed low ISO with longer shutter just resulted in blurred images - too much vibration or wind shaking the tripod. Higher ISO (800-1000) allowed shutter speeds of 1/15 or 1/30s which worked much better. Couldn't get a clearer shot of Jupiter itself - any longer exposure lost the moons without bringing out any more detail on the planet. Shot of moon and Jupiter a composite of two exposures, one for moon, one for Jupiter. Moon shot f8, 1/160s at ISO 200.