Deneb, Sadr and the North America nebula

Region of Cygnus showing the North America and Pelican nebulae (the Pelican is much fainter than North America, but with a little imagination it can be seen, facing the ‘gulf of Mexico’.

The brightest star in the field is Deneb, and Sadr with the nearby gamma Cygni nebula is to its lower right.

Imaged on 12 September 2015 with a Nikon D810A DSLR and Nikkor 80-400 zoom lens at 80mm; 180-second guided exposure at f/4.5, ISO 250. A satellite crossed the field during the exposure.

Both this and the image below were intended just as tests for my Nikon D810A camera to see how well its extended red sensitivity would reveal the nebulae glowing in H-alpha light. The results were better than expected so I have included them here.

Note that these are guided exposures. The D810A allows up to 15-minute timed exposures without resorting to the Bulb setting. At 800mm focal length such long exposures require guiding. The rig used was an iOptron ZEQ25 mount which allows dual-axis guiding. The camera was mounted in tandem with a small guidescope and the mount was controlled with a notebook computer running PHD2 software.

As a further test I went on to image the North America nebula NGC 7000 at the higher focal length of 800mm. The resulting 5-minute exposure shows good H-alpha sensitivity and the quality of the autoguiding at this focal length was pleasing.

Nikon D810A with Nikkor 80-400 zoom and 2x teleconverter at 800mm, 300-second guided exposure at f/11, ISO 500 using an iOptron ZEQ25 mount and PHD autoguiding.