Apart from the usual facilities you’d expect to find on a modern DSLR camera, it has added usefulness thanks to a couple of rather interesting extras that really help when astro imaging.
The Nikon’s live view is easy to use due to its multi-stepped zoom capability.
It just felt more natural to use than most we’ve tested; we also really liked the inclusion of the settings control screen at the top of the D90.
However, we weren’t so keen on having to use both hands to perform some of the setting changes, such as the ISO value, because this was often awkward to do in the dark.
The Nikon comes with some interesting extra features such as colour fringe reduction, ‘Active D-Lighting’ for improved detail in shadow areas, and a movie-recording mode.
The last item might grab your attention if you’re into lunar or planetary imaging, especially when you realise that the D90 is capable of capturing movies in a 1,280×720 format, at a frame-rate of 24 frames per second.
However, there’s a catch, because the movie is saved in a compressed motion-JPEG format, a file that’s not ideal for stacking images for crisp shots of the planets.
Even so, the movie mode adds a further dimension to what the camera can record.
We could see it being useful for capturing events like lunar occultations of bright planets, a pass of the International Space Station or a total solar eclipse.
The Nikon has an ISO range of 200 to 3200 with three lower settings of L0.3, L0.7 and L1.0, which correspond to ISO 160, 125 and 100 respectively.
Three higher settings of H0.3, H0.7 and H1.0 correspond to ISO 4000, 5000 and 6400 respectively.
Noise tests carried out at ISO 100 (L1.0) showed that the Nikon produces little noise at this setting.
Noise values at ISO 1600 were also very acceptable.
At yet higher ISO settings noise effects started to appear, but these settings would still be useful for short-exposure, high-sensitivity applications such as recording a meteor shower.
Our nebula test image at ISO 1600 showed excellent detail and revealed the faint dark lanes in the Running Man Nebula.
The 920,000-pixel review screen delivered detailed and vibrant review images.
However, the main optical viewfinder’s dioptre adjustment (a tweak that compensates for your level of eyesight) was a bit limited compared to the other cameras and won’t compensate if you have particularly bad eyesight.
In conclusion, this is a camera capable of producing excellent astrophotos.
Everything works well and despite a few two-handed setting changes, the simplicity of the live view function was the best in this review.
You’re unlikely to be disappointed with the astronomy capabilities of this excellent camera.
This review first appeared in the May 2009 issue of Sky at Night Magazine