Last night I shot into the autumn Milky Way at the Heart Nebula.
I’m currently just finishing off a month of testing the new Nikon D810a camera, a special high-end DSLR aimed specifically at astrophotographers.
I’ll post a more thorough set of test shots and comparisons in a future blog, but for now here are some shots from the last couple of nights.
Above is the setup I used to shoot the image below, shot in the act of taking the image below!
The Nikon is at the focus of my much-loved TMB 92mm refractor, riding on the Astro-Physics Mach One mount. The mount is being “auto-guided” by the wonderful “just-press-one-button” SG-4 auto-guider from Santa Barbara Instruments. The scope is working at a fast f/4.4 with the help of a field flattener/reducer from Borg/AstroHutech.
I shot a set of 15 five-minute exposures at ISO 1600 and stacked, aligned and averaged them (using mean stack mode) in Photoshop. I explain the process in my workshops, but there’s also a Ten Steps page at my website with my deep-sky workflow outlined.
The main advantage of Nikon’s special “a” version of the D810 is its extended red sensitivity for a capturing just such objects in the Milky Way, nebulas which shine primarily in the deep red “H-alpha” wavelength emitted by hydrogen.
It works very well! And the D810a’s 36 megapixels really do resolve better detail, something you appreciate in wide-angle shots like this one, below, of the autumn Milky Way.
It’s taken with the equally superb 14-24mm f/2.8 Nikkor zoom lens. Normally, you would never use a zoom lens for such a demanding subject as stars, but the 14-24mm is stunning, matching or beating the performance of many “prime” lenses.
The D810a’s extended red end helps reveal the nebulas along the Milky Way. The Heart Nebula, captured in the close-up at top, is just left of centre here, left of the “W” forming Cassiopeia.
The Nikon D810a is a superb camera, with low noise, high-resolution, and features of value to astrophotographers. Kudos to Nikon for serving our market!
– Alan, November 30, 2015 / © 2015 Alan Dyer / www.amazingsky.com