Nikon has just announced its first digital SLR optimized for astrophotography: the D810A. Like the D810 on which it’s based, it’s a 36-megapixel, full-frame camera. Unlike the D810, but like the Canon EOS 60Da and digital SLRs modified by third parties, its infrared filter is optimized to let in hydrogen-alpha wavelengths crucial to photographing emission nebulae and star-forming regions that emit light in those frequencies. It’s also capable of taking exposures up to 15 minutes long and has a new preview mode that simulates 30-second exposures.
Tweaking a camera for increased hydrogen-alpha sensitivity and longer exposures can make a world of difference in astrophotography: the former brings out a lot more colour and detail in those aforementioned nebulae (see sample images from the D810A here and here; the product page has a nifty comparison of D810A vs. D810 images of the same astronomical objects). But to be clear, the D810A’s modified IR filter renders this camera unsuitable for regular photography: the white balance will be permanently out of whack. This is not a camera for someone who would normally buy a D810 and wants to dabble with astrophotography on the side. And it’s not cheap, either: at US$3,800/C$4,450, it costs US$500/C$850 more than a regular D810.
So why buy one? Well, you get better results than you would from a digital SLR. And compared to dedicated astrophotography cameras, a digital SLR is considerably easier to use: dedicated cameras have to be connected to a computer via USB and their images require more processing, though the single-shot colour cameras are undoubtedly less difficult to use than the monochrome cameras that require you to record each colour channel separately. And even at the D810’s price, it’s still cheap: dedicated cameras that use large sensors can cost four or five times as much. (Astrophotography is an expensive hobby.)
And you can easily use a camera lens instead of a telescope, which makes this sort of camera ideal for wide-field astrophotography.
The only other digital SLR optimized for astrophotography is Canon’s EOS 60Da. It’s cheaper but has a smaller (APS-C sized) sensor. The conventional wisdom on digital SLR astrophotography has been to prefer Canon over Nikon cameras, partly because Canon has been making modified digital SLRs before today, and partly because Nikon’s noise reduction algorithms have tended to mess with star fields (the so-called “star eater” effect; I don’t know if this is the case with newer cameras). This changes things up a bit.
Previously: New Canon Digital SLR for Astrophotography.