Galactic Cliffs

A few weeks ago I held a small group workshop in Acadia, and while one of my attendees was shooting a panorama on Boulder Beach, I tried out my new Sigma 50mm f/1.4 Art lens aimed at Otter Cliffs. This lens is amazingly sharp even at f/1.4, and coma distortion of the stars in the corners and edges isn't terrible at f/1.4 but it is better at f/2. But to get the most light in I stuck with f/1.4 and decided to live with the "flying saucer" effect that it causes to the brighter stars near the edge of the frame. As far as I can tell, this 50mm lens has the least amount of coma distortion on the market at f/1.4. With 50mm you get star trails pretty fast, so I limited my exposures to 3 seconds, and used star stacking to take multiple exposures of the sky to reduce noise in software.

This was also an accidental exercise in ETTR, exposing to the right, at a very high ISO and seeing that it was very usable. I accidentally left the ISO at 12,800 for a 4 minute foreground exposure at f/2, which blew out the sky and while the foreground looked very overexposed it was perfectly in tact without being blown out. In digital photography, the brighter the exposure, the less noise you'll have, even at high ISOs. This is just the way electronic cameras work, essentially raw files have more bits available to represent brighter tones. A very bright "overexposed" shot at ISO 12,800 can in fact have a very similar noise result as a "well exposed" (darker) shot at ISO 3200. It's all too much to explain here, but if you look up Expose To The Right, you'll learn all about the technique. In this case, I also had an ISO 3200 shot to compare to. The ISO 12,800 shot was at f/2 for 4 minutes, and the ISO 3200 shot was at f/1.4 for 2 minutes, so the 12,800 shot was a full 2 stops brighter than the 3200 shot. Comparing them side by side in Lightroom, with the 3200 shot brightened 2 stops, I can see that the 12,800 shot is just as clean as the 3200 shot, and of course it's sharper with more in focus because it was at f/2.

Nikon D810A with Sigma 50mm f/1.4 Art lens. Total of 11 exposures, 10 for the sky at f/1.4, ISO 12,800, for 3 seconds each, blended with Starry Landscape Stacker on the Mac for pinpoint stars and low noise. The foreground is from a single ISO 12,800 shot at 4 minutes and f/2.

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Make:	NIKON CORPORATION
Model:	NIKON D810A
Exposure:	240
Aperture:	f/2.0
ISO Speed:	12800
Focal Length:	50 mm
Lens:	50.0 mm f/1.4