After yesterday’s post, I got some requests about how well the new Nikon 20mm f/1.8 AFS G Nikkor lens handles chromatic aberration (CA). For the record, when I test a lens, I try not to obsess about lab benchmarks and instead focus on just using the lens. I haven’t been able to go out to use this new lens in a real situation yet, but so far I’ve seen nothing to suggest that this lens isn’t an excellent addition to the Nikkor line.
So, a quick CA test for all the pixel-peepers after the jump.
Here are 100% (1:1) views of CA, with the image captured at f/2.0. As with most lenses, CA, and light fall-off all disappear as you stop down.
Magenta and green fringing extends for 2-4 pixels (D810) at f/2.0. Notice that the color-fringing is only present when I disabled CA removal in Lightroom 5. Once I turned on the automatic CA removal, the color-fringing disappeared. Like light fall-off, these aberrations are really only a problem if you shoot JPEG and don’t apply any corrections to your images. For most photographers, these are non-issues, as they are corrected by a single click in your editing application. In fact, I’ve set up Lightroom to enable CA removal by default for all my cameras, something I cover in my Lightroom 5 guide.
Did you happen to notice how the coma was? I’m considering this lens for astrophotography. So far I’ve seen/read mixed comments in that regard.
I didn’t really investigate it. I’m happy with my images so far but I’m not an astrophotographer by trade.
You already have a photo from your “Milky Way over Carhenge” article. It’s too small for me to tell but you could look at the original and see how the coma is. If it’s too much trouble, never mind.