Lens Format: Full Frame 35mm FX
Focal Length: 24mm FX Sensor (36mm DX Sensor)
Min/Max Aperture: F/1.8 - F/16
Lens Design: Prime
Lens Optical Design: 12 elements in 9 groups - 2 ED glass elements - 2 Aspherical
Maximum Field Of View: 84 Degress (FX) 61 Degress (DX)
Diaphram Blades: 7
Nano Crystal Coating: Yes
Focusing Mode: Auto Focus / Manual Focus
Filter Size: 72mm Screw on
Weight: 355 grams
The Nikkor AF-S 24mm F/1.8G lens is a light weight prime 24mm focal length lens that fits nicely in the hand.
The lens looks to be constructed out of plastic with a plastic lens hood and lens cap which in turn keeps weight down for portability, the gold ring indicates a professional grade / weather sealed lens.
The focus ring is nice, wide and made of rubber which gives a nice feel to it. With the textured rubber focusing ring you don't feel like your fingers are going to slip off it. When manually focusing you get the feeling of it being smooth with some resistance which I like, this way I know my focus won't change easily.
For night scape photography we tend to look for lenses with a lot of light grasp. The Nikon AF-S 24mm F/1.8G Nikkor lens has this, wide open at F/1.8 it lets in plenty of light. However when shooting the night sky our lens optics are certainly pushed to their limits. The next question we need to ask is how many aberrations are seen with the lens.
Chromatic aberration is well controlled, at F/1.8 you do notice a slight purple hue to some of the stars but not all, by F/2.2 I didn't notice anything thanks to the two ED glass elements (Extra-low Dispersion).Shooting at F/1.8 chromatic aberration can be easily corrected in Adobe Lightroom...So that's a tick in my book!
Let's move on to the next form of aberration... Coma. Coma in this lens is noticeable at F/1.8 however again by F/2.2 this is dramatically reduced. Only in the outer corners do you notice this at F/1.8.
Using this lens with a DX sensor I would say shooting at F1.8 you wouldn't notice the majority of the aberrations as your shooting through the more central section of the lens, however this was not tested so I can't say for sure.
My Overall Thoughts
I was really happy with this lens shooting wide open at F1.8, a lot of the aberrations were easily corrected in Adobe Lightroom by applying the lens correction function along with the chromatic aberration checked. Vignette isn't really an issue, again by applying the Adobe Lightroom lens correction to your image it flattens and reduces any vignette the lens may have.
The light weight of this lens means you can use this without a problem on most portable tracking mounts for tracked images of the night sky.
Shooting wide open meant I could use a lower ISO setting reducing the amount of camera noise in my photo. I also noticed this lens picked up a nice amount of sky glow and red nebulosity which is also thanks to the Nikon D810a.
Image: Nikon AF-S 24mm F/1.8G ED Nikkor - Shot at F/1.8, 20 second exposure, 3200 ISO