NikonGear'23

Gear Talk => Lens Talk => Topic started by: Nikfuson on June 05, 2020, 15:16:20

Title: Nikkor Z - 20/1.8S exploration
Post by: Nikfuson on June 05, 2020, 15:16:20
I have this lens on trial.
Will try and exemplify and comment on my findings over the next few days.
It is physically a long lens but the balance is near perfect on the Z6. AF is dead silent. Vignetting is pronounced.
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: Nikfuson on June 05, 2020, 18:27:27
First some boring optical considerations.
Barrel distortion (red rectangle to ease the effect) is mild and easily corrected.
Vignetting amounts to ca. 2EV.
Slight but not bothersome LoCA (two images with red squares to indicate point of focus).
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: Nikfuson on June 05, 2020, 22:01:54
A few landscapers.
First one at f/2, the three next ones at f/11.
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: Nikfuson on June 05, 2020, 23:45:08
Coma test (f/1.8 ). Pretty good. Possible sliiiiight decentering, but now I'm splitting hairs!
What I like is the possibility to capture landscapes at f/1.8 with across the frame sharpness.
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: Hugh_3170 on June 06, 2020, 08:13:58
Looks good.  Thanks for posting these images.

Have you compared the Nikkor Z and Nikkor F versions of the 20mm f/1.8 lenses?
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: Nikfuson on June 06, 2020, 08:45:19
Looks good.  Thanks for posting these images.

Have you compared the Nikkor Z and Nikkor F versions of the 20mm f/1.8 lenses?

No, but that will be my next task. Despite the S being good, the price is perhaps too high to justify it over the G.
As I don’t have a 20mm in my stable I am cosidering the G over the S due to 50% cost saving.
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: Birna Rørslett on June 06, 2020, 10:34:09
I have the 24 S/G to make a comparison and in this case, although the F-mount version is very good, the S lens is even better. They both have that modern, clinical touch about their rendition, though. For this reason I often haul out my older AI/AIS 24 Nikkors, both f/2 and f/2.8.

I own and use the 20/1.8 G. It is up there at the level of the 24/1.8G. Thus I expect  20/1.8S to be its peer if not the better of them.

Improved flatness of field even up close apparently is a hallmark of these new S-Line Nikkors.
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: chris dees on June 06, 2020, 21:44:32
According to Nikon Ricci the S-Mount is quite a bit better than the F-Mount
https://www.youtube.com/watch?v=h8zGE9SbVY0
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: Erik Lund on June 08, 2020, 08:36:08
Thank all, looks very impressive to me the new S
looks like it does sun stars very nicely, few 'modern' designs does that (G type F-Mount) so,,, different coatings or?
The 'old' 20mm f1.8G is still a very nice sharp lens, but yes so many
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: Roland Vink on June 09, 2020, 00:26:35
Thank all, looks very impressive to me the new S
looks like it does sun stars very nicely, few 'modern' designs does that (G type F-Mount) so,,, different coatings or?
The 'old' 20mm f1.8G is still a very nice sharp lens, but yes so many
Crisp sun-stars are usually caused by straight-edge aperture blades, so the light is diffracted all in the same direction. Curved aperture blades causes the light to diffract in different directions, causing more diffuse sun stars. I don't think lens coatings have much influence on this.

Lens specifications state it has a rounded diaphragm opening, but maybe from f/5.6 or smaller, the curved section overlaps the next blade so only a straight edge remains. This would be the ideal design - at wider apertures bokeh is a greater consideration so the aperture is rounded to make bokeh balls look more rounded and natural. At smaller apertures the DoF is greater, bokeh is less important, so the diaphragm can transition to a straight-edge opening to give cleaner sun stars.
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: Macro_Cosmos on June 19, 2020, 23:00:40
Here's mine. Centre and 4 corners.
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: Macro_Cosmos on June 19, 2020, 23:02:25
F5.6 starburst. Not sure if it's technically good or bad, but I do really like it!
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: Jan Anne on June 20, 2020, 14:38:47
Seems to be a fine lens, thanks for sharing your findings :)
Title: Re: Nikkor Z - 20/1.8S exploration
Post by: simsurace on June 20, 2020, 22:25:14
That‘s a very crisp sunstar in my book.