Since Nasim has been photographing the beautiful golden aspens in Ouray County, Colorado with members of the Photography Life community for the last few days, I thought I would provide some early thoughts and samples of photos taken with the new Nikon AF-S 20mm f/1.8G ED. Once Nasim is back in town, he will post a much more detailed review of this lens. I would call this a “Nasim Light Lens Review,” but that would be giving myself too much credit!
Many have been very impressed with the Nikon’s f/1.8G series, which includes the 28mm, 35mm, 50mm and 85mm. Each represents a great value relative to their more expensive f/1.4 counterparts, and in some cases, as good if not better performance. And while the new 70-200mm f/4 VR lens is not one of the f/1.8G series, it represents the same style and value proposition.
I had previously owned the 28mm f/1.8G, which I loaned to Nasim for his detailed review. It was a fine lens, but I did not find the focal length to be very useful. It was not a wide angle lens and was just 7mm shy of my Sigma 35mm f/1.4. The only real advantage it had over the Sigma was weight. The Sigma is such an exceptional lens, however, so I eventually sold the 28mm f/1.8G. What I really wanted was an 18mm or 20mm f/1.8G. Nikon finally answered the call.
As you can see from the test charts below, the 20mm f/1.8G delivers on the sharpness front. It certainly kept up with my Nikon D810. Wide open I can detect a slight degree of softness when zoomed in at 100%, but with basic sharpening, images become very crisp. Even the corners turn in very good performance wide open. I have tested quite a few of Nikon’s best lenses using this chart and the corner performance of the 20mm f/1.8G is as good as any I have seen. The only sharpness I applied (apart from the noted photo below) was 25%, radius of .5, and detail of 50% in Lightroom, which had a negligible impact.
1.1) @ f/1.8
Same crop with a bit of SmartSharpen in Photoshop using values of 100% and a 1.25 radius:
Red square = area of focus.
1.2) @ f/2.8
1.3) @ f/4
1.4) @ f/5.6
1.5) @ f/8
Astrophotographers are primarily concerned with fairly wide focal lengths, large apertures, and minimal comatic aberration, more commonly known as “coma.” A lens may meet the first two criteria but fail miserably on the third, making it a bad choice for astrophotography. Canon’s 24mm f/1.4 L II lens falls into this category – a great overall lens, but not the best option or value for astrophotography. Rokinon/Bower/Samyang’s 14mm, 24mm, and 35mm manual focus lenses are reasonably priced, very sharp, and most importantly, feature minimal chromatic aberration. Thus they have become very popular in the astrophotography community.
Just about any lens will exhibit some level of coma wide open. The issue is one of how pronounced or exaggerated it is relative to other lens offerings. Most lenses dramatically improve their coma performance as their aperture is stopped down. Of course, that defeats the purpose of having a wide aperture lens and increases the ISO value required to prevent star trails.
I took a number of photos of Pittsburgh’s night skies and was surprised to find something unusual – stars! If you know anything about Pittsburgh, you may realize that it experiences more cloudy days than Seattle. Thus I had a bit of luck in receiving my 20mm f/1.8G and having a cloud-free night in Steel Town.
As you can see from the photos, the 20mm f1.8G showed a bit of coma in the far corners of the photos. Relative to the results of other top-notch lenses used for astrophotography, the 20mm f/1.8G wide-open held up extremely well. Bad coma appears to be characterized by a bright blur that forms a crescent area around the star. The 20mm f/1.8G’s coma appears to be a very slight. I found the results to be consistent over a dozen photos. Due to the ambient light of the suburbs, I didn’t capture the full effect of the night sky. No doubt Tom Redd or Nasim will be able to better showcase this lens’ astrophotography capabilities in their native Colorado. Based on my comparing the 20mm f/1.8G’s performance to that of other lenses on some of the more popular astrophotography sites, I thought it did an excellent job.
3) General Use
The next day, I wandered around Pittsburgh’s Hartwood Acres and captured some photos of the various scenes associated with the Hay Day Fall Festival. I found the 20mm f/1.8G to be incredibly sharp. I didn’t have an Adobe Camera RAW lens profile available, so did not compensate for distortion or vignetting. I am sure a profile for this lens will be released in the next few weeks that will address these concerns.
This may be the first camel photographed with the Nikon 20mm f/1.8G lens (Nikon staffers are diligently looking into this and expected to get back to me at any moment).
The camel repeatedly attempted to lick or take a bite out of my 20mm f/1.8G, but I thought I would leave the “20mm f/1.8G Torture Test” for another day. Below are some other shots taken with the 20mm f/1.8G at various apertures.
Like the other lenses in Nikon’s 1.8G series, the 20mm f/1.8G offers great performance at a great price. It has a bit of distortion and vignetting, but no more than what one would expect for a lens in this class. The 20mm f/1.8G hits all the right checkboxes – excellent image quality, value-based price, wide focal length, wide aperture lens, light, and compact. The fact that it turns in solid astrophotography results will no doubt widen its appeal.
I believe the 20mm f/1.8 will be a huge seller, and ultimately much more popular than the 28mm f/1.8G, since it provides a far more usable focal length and more reasonable spacing from the 35mm focal length. Keep an eye out for Nasim’s upcoming detailed Nikon 20mm f/1.8G review. If you decide to purchase the lens, please do so by clicking here and helping to support this site.