The folks at Nikon have announced the new D810A. The camera is a specific design for astrophotography. Nikon has customized the camera for this specific set of tasks. Astrophotography tends to be done in the dark, working with very distant subjects. Sharpness is critical and the photographer is dealing with many challenges. There is the interference from the atmosphere, there is the challenge of getting the right colour. Neither the D810 nor the D810A have an optical low pass filter, but the D810A adds an IR cut filter to specifically allow frequencies in the 656 nanometer wavelength to pass Hydrogen - Alpha and render the reds in astronomic subjects properly.
Because of this custom design, the D810A will render some subjects warmer than they really are, particularly those captured in fluorescent lighting. Nikon does not recommend the D810a for general photography.
The sensor is a 36.3 MP full frame DX sensor. It's ISO range is 200-12,800 with a push setting of 51,200. If that sounds familiar, it should because excepting the astrophotography specific functionality, this a Nikon D810. So everything you know that's great about the D810 is in the D810A, but rebuilt specifically for astrophotography.
But, if outer space is your place, this camera is built for you. No more guessing or buying external timers, no more failed previews. The D810A extends the usual band of shutter speeds through the new long exposure manual mode. Starting at 4 seconds, the new mode gives a range of 4, 8, 15, 30, 60, 120, 180, 240, 300, 600 and 900 seconds. You of course still have bulb and timer modes available.
The new virtual preview function extends the typical LCD functionality to show previews of images of up to 900 second exposure. The default previews go black after 30 second exposures in Live View.
I wish I lived in a location where there was so little light pollution that I could actually get out and test this camera. Since I don't, I can only share with you the sample images provided by Nikon.
The D810A is expected to be on dealer shelves by May 2015 at a price of $4,499.99 Canadian.