Weather ordinary.... Operator competence - worse....
I've only used my Coronado scope in anger once, and remembered having trouble focusing it - I hadn't pulled out the draw tube from the focuser....
So yesterday I thought nothing for a while when I couldn't focus, then pulled out the tube - still couldn't focus.... nearing desperation as the sun descended towards a nearby rooftop amongst the clouds, realised I'd left the dang lens cap on!