Kenneth Almquist
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My experience is that when I try to use a wide angle lens, I tend to end up with unwanted gunk in my photos. But when this already inexpensive lens went on sale, I decided to buy one and see if I could come up with some decent compositions with it. If not, I'd know that it would be pointless for me to spend $900+ for one of Nikon's excellent wide angle primes.
Let's start with sharpness. Here is a 100% center crop, taken on a 45 megapixel Z8:
This is processed with dcraw with no sharpening or color saturation increases, which is why it looks kind of dull. Now for the four corners:
upper left
upper right
lower left
lower right
The first thing you will notice in these corner crops is that the tower appears to be tilted. That's the result of perspective distortion, which as you can see can be pretty dramatic on a 20mm lens.
The second thing you may notice is that the color of the sky is slightly different in the corner crops than in the center crop. All five images were processed using the same white balance, so I believe the lens has a color cast that is a bit different at the corners than in the center.
A third thing you would notice if I hadn't corrected it to make it easier to judge sharpness is that the lens has a lot of vignetting. I brightened the corner crops by 1.8 stops in order to approximately match the center crop.
I was surprised by how sharp this lens is. Pixel peeping on a 45 megapixel camera reveals softness in the corners, but I doubt that anyone viewing an entire photograph (rather than pixel peeping) would notice. So let's look at some photos.
Only use this lens for wildlife if you don't mind the scenery dominating your wildlife. Out of focus branches against a white sky is something to be avoided when using a lens with significant chromatic aberrations. Here there is a small amount of purple fringing, but not enough to be objectionable.
The bird is out of focus, but that's a deficiency in the photographer rather than the lens. The vignetting is really obvious in this shot. I'm just posting out-of-camera JPEG images here. Eliminating vignetting is one reason to process raw images yourself (rather than relying on the camera's JPEG engine) if you use this lens.
The lens has limited closeup abilities. (The long dimension of an uncropped image is slightly under 8 inches at closest focus.)
The lens can produce sun stars. The next photo is shot at f/16, but sun stars appear at all apertures.
Autofocus appears to be fast, and the lens produces full EXIF data. The only compatibility issue I found is a minor one: when the lens is focused at infinity, the Z8 thinks it is focused at a distance of about 10 meters.
According to one review, the lens has some field curvature. This may be true, but if so the relatively large depth of field of this lens prevented me from noticing it. The lens is also reported to have a low total distortion but a rather complex wavy distortion pattern. I didn't shoot anything with straight lines, so this hasn't shown up in my photos.
The bottom line is that this lens is quite usable. Even if I come to like this focal length, I'm not sure I'd feel the need to buy the Nikon lens.
Let's start with sharpness. Here is a 100% center crop, taken on a 45 megapixel Z8:
This is processed with dcraw with no sharpening or color saturation increases, which is why it looks kind of dull. Now for the four corners:
upper left
upper right
lower left
lower right
The first thing you will notice in these corner crops is that the tower appears to be tilted. That's the result of perspective distortion, which as you can see can be pretty dramatic on a 20mm lens.
The second thing you may notice is that the color of the sky is slightly different in the corner crops than in the center crop. All five images were processed using the same white balance, so I believe the lens has a color cast that is a bit different at the corners than in the center.
A third thing you would notice if I hadn't corrected it to make it easier to judge sharpness is that the lens has a lot of vignetting. I brightened the corner crops by 1.8 stops in order to approximately match the center crop.
I was surprised by how sharp this lens is. Pixel peeping on a 45 megapixel camera reveals softness in the corners, but I doubt that anyone viewing an entire photograph (rather than pixel peeping) would notice. So let's look at some photos.
Only use this lens for wildlife if you don't mind the scenery dominating your wildlife. Out of focus branches against a white sky is something to be avoided when using a lens with significant chromatic aberrations. Here there is a small amount of purple fringing, but not enough to be objectionable.
The bird is out of focus, but that's a deficiency in the photographer rather than the lens. The vignetting is really obvious in this shot. I'm just posting out-of-camera JPEG images here. Eliminating vignetting is one reason to process raw images yourself (rather than relying on the camera's JPEG engine) if you use this lens.
The lens has limited closeup abilities. (The long dimension of an uncropped image is slightly under 8 inches at closest focus.)
The lens can produce sun stars. The next photo is shot at f/16, but sun stars appear at all apertures.
Autofocus appears to be fast, and the lens produces full EXIF data. The only compatibility issue I found is a minor one: when the lens is focused at infinity, the Z8 thinks it is focused at a distance of about 10 meters.
According to one review, the lens has some field curvature. This may be true, but if so the relatively large depth of field of this lens prevented me from noticing it. The lens is also reported to have a low total distortion but a rather complex wavy distortion pattern. I didn't shoot anything with straight lines, so this hasn't shown up in my photos.
The bottom line is that this lens is quite usable. Even if I come to like this focal length, I'm not sure I'd feel the need to buy the Nikon lens.
