Nikon Introduces Mirrorless 85mm/f1.8 S Lens

[ShunCheung]

However, if you look at the diagram showing the optical elements in the 85mm f/1.8 S

 

Nikon | Imaging Products | NIKKOR Z 85mm f/1.8 S

 

it shows that the rear element extends closer to the sensor than the bayonet and so should be very close to the sensor itself, and covers the opening. This probably means some optical benefits to the user, as well. The MTF for 30lpmm is above 0.8 from image center to 15mm off-center (10lpmm line around 0.97), covering most of the image area. The older AF-S 85/1.8G MTF is between 0.5 and 0.7 within the same area of the frame (10lpmm line 0.9), suggesting there is a noticeable improvement in image detail and contrast. Corner sharpness in this case does not appear to be improved, but there is less divergence between tangential and sagittal MTF curves, so this could translate to better bokeh.

 

I took liberty to copy Nikon's cross-section diagram for the 85mm/f1.8 S below. Its rear element (on the right side) actually extends a bit beyond the flange so that it is roughly 11mm from the sensor. In fact, there is a bunch of elements towards the rear end of this lens occupying the space where the mirror would have been for an F-mount lens. In other words, even the design of this short tele is taking advantage of the absence of the mirror. It is not restricted to only wide-angle lenses taking such advantage.

 

I happen to have both the 85mm/f1.4 and f1.8 AF-S. It would be interesting to compare against this new lens

when it is available.

 

 

Edited August 1, 2019 by ShunCheung

[Ed_Ingold]

I'm thinking of cars exported to the US.

 

Not many people will "convert" from iPhones to mirrorless. Those serious about photography already have SLRs, and will be the first to change over.

[rodeo_joe1]

In other words, even the design of this short tele is taking advantage of the absence of the mirror.

Speculation.

The real performance of the lens remains to be seen. And who's to say that its performance couldn't be matched in a DSLR lens, at the same price point, and with comparable optical complexity, size and weight?

 

The fact that Nikon's lens design team, or their software, has chosen to move the rear group backwards, doesn't mean they had to in order to achieve the same design goal.

 

The fact remains that it's a bulky and expensive lens for an f/1.8 short tele.

 

I'm afraid the Nikon name no longer carries the cachet to play Leica's game of pricing based on the strength of reputation alone. They've come late to the feast and shouldn't expect to get a free seat at the top table. They now need to elbow their way in by having a keen and attractive price structure.

[Ed_Ingold]

Judging from Nikon MTF data, their designers have put the extra space to good use.

 

Nikon | Imaging Products | AF-S NIKKOR 85mm f/1.8G

Nikon | Imaging Products | NIKKOR Z 50mm f/1.8 S

 

MTF is not the only criteria for choosing a lens. Freedom from chromatic aberration, astigmatism and distortion are important too. Build quality is very important, considering how long a lens exists without becoming obsolete, and much harder to assess. Other factors are even more elusive. How does it feel in your hands, too heavy, too light, too tight, or too loose?

 

True, you often pay for a name, but usually that "name" was earned by a long history of high quality in every respect.

[ilkka_nissila]

Speculation.

The real performance of the lens remains to be seen. And who's to say that its performance couldn't be matched in a DSLR lens, at the same price point, and with comparable optical complexity, size and weight?

 

We already can guess what to expect from the 85mm based on the 35/1.8 S and 50/1.8 S, their optical and autofocus performance relative to the F mount versions and the published MTFs. Yes, the lens needs to be tested in practice, but so far the record is very good for S line lenses.

 

The fact that Nikon's lens design team, or their software, has chosen to move the rear group backwards, doesn't mean they had to in order to achieve the same design goal.

 

I'm not a lens designer but my understanding is that if the elements are all far away from the lens, it is more difficult to avoid aberrations as the elements have to bend the light more than if some of them are closer to the sensor surface. If you have a larger number of elements and some that are close to the sensor it's possible to play with the materials in such a way that CA is largely eliminated.

 

The fact remains that it's a bulky and expensive lens for an f/1.8 short tele.

 

I would put it in a different way: it is relatively affordable and lightweight for a high quality 85mm and its size and weight seem to be in line with that of the Z6/Z7 camera bodies. The Batis 85mm f/1.8 is $1079 and Sony 85mm f/1.8 is $598. Nikon seems to be pricing their product close to the competitors' offerings in the full-frame mirrorless lens marketplace.

 

I'm afraid the Nikon name no longer carries the cachet to play Leica's game of pricing

 

Leica's 90mm f/2 costs $4595, the Nikon Z 85/1.8 S is $796 at B&H. Why are you even putting the two in the same sentence?