Less than 24 hours to go and I’m on Scout Scar, checking conditions for the eclipse the next morning. Under a full moon, the “Mushroom” is as bright as day – only Orion in the background betrays that it is 9pm in December.
The Moon looks good through a Nikkor 500mm reflex telephoto, but this lens does not have a “hard stop” when focused at infinity, so focus adjustment is by eye. As this involves rotating the full barrel of the lens, it is very trying. There is no easy fine-tuning, and the aperture is fixed at f/8, so there’s no stopping down for depth of field.
The most productive option is to use the “Live View” display on the D90, which can be zoomed and panned while focusing. That can’t be done while wearing gloves, however, and it’s already well below zero. Tomorrow morning is forecast to be minus 15.
With the Sigma 2x converter, the lens doubles up to a 1000mm f/16. Focusing difficulty doubles up too. I’m never really sure whether it’s in focus at 1000mm. Perhaps the image is slightly soft, even when in sharp focus.
Contrary to expectations, the Moon isn’t an inspiring subject when full. The light is just flat and there’s no detail.