I am considering the 36-megapixel Nikon D810A, which was optimized for astrophotography. That sounds great since I do want to photograph stars, in addition to people, nature and landscapes. Nikon’s website says that the D810A is not recommended for general photography because the images will have a reddish tint. But surely that would be easy to correct if I used it in the Raw (NEF) capture mode for all of my photography. Am I wrong about this?
I should briefly summarize how Nikon’s D810A primarily differs from the D810 before addressing your question, Tyler. This new model is identical in many aspects, but its IR cut filter was modified so it’s four times more sensitive to the H-alpha spectral line (a wavelength of approximately 656 nm). That allows for capturing the reddish colours of nebulae and constellations that emit the hydrogen-alpha wavelength. Check out some of the effects that can be obtained with the D810A in this video: Nikon D810A: The World of Astrophotography. There’s no need for the special modifications by third party companies required on a conventional DSLR that will be used strictly for astrophotography. (Such conversion voids the camera’s warranty and may produce other problems.)
In any event, your theory certainly sounds reasonable, Tyler, since a colour cast in a Raw photo can be easily removed with Raw converter software such as Nikon NX-D, as you know. Of course, the Nikon engineers are equally well aware of that, and yet, the company specifically bills the camera as “exclusively for astrophotography.” To get an educated answer, I posed your question to Nikon Canada. Their tech expert commented as follows: While certain environments may induce a colour cast over the entire photo, as in an environment illuminated by fluorescent tubes, the increased reddish colour cast may affect only a small portion of a conventional photo [made with the D810A]. For example, the red tinge might only appear on a purple flower or on black clothing with a high reflectance. If it appears on a small portion of the photo, editing the Raw file may not fully correct the problem.
You’ll need to decide which is a priority: a camera for astrophotography or for general-purpose photography. Should you decide that your greatest need is for a DSLR to be used to document nebulae and constellations, then sure, the D810A makes sense. In addition to the modified IR cut filter, this new model provides other benefits for astrophotography. These include longer battery life, shutter speeds up to 900 seconds in M mode and Virtual Exposure (at 30 sec. or longer) to provide a brighter Live View on the LCD for more effective focusing and composition.