Nikon has unveiled a modified version of its D810 DSLR camera designed for use in astrophotography. The D810A has the same 36.3-megapixel CMOS sensor and EXPEED 4 image processor as the standard version, along with most of its functionality, but its infrared cut filter has been adjusted to let through hydrogen alpha spectral line transmissions, making it four times as sensitive for 656nm-wavelength light.
