str8pipe
Forum Enthusiast
Is there technical reasons why Nikon doesn't produce this lens?
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Reasons why no Nikon 85mm f1.2?
- Thread starter str8pipe
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Mssimo
Senior Member
Leonard Migliore
Forum Pro
The mount's not big enough.
There's a discussion here about putting a CPU chip on a 50mm f/1.2 AI-S Nikkor and it was noted that you have to grind a piece off the rear element to get space for the contacts.
It is also true that sensors are not as good as film at picking up off-axis light, so an f/1.2 is not going to be a whole lot brighter than an f/1.4.
Grevture
Senior Member
1. With the diameter of the f mount, Nikon can without to much trouble make lenses in the 50-60 mm focal range with f1.2, longer then that, you will run in to trouble with the lens mount.
2. As others have pointed out, f1.2 in practical terms means negligible amount of extra light compared to f1.4. The wider the aperture, the more angle of incidence light will have when it hist the sensor. As we get progressively higher resolutions, this gradually becomes more and more of a problem. Already, with most fast wide angle lenses, you get roughly only half a stop of extra light going from f2 to f1.4 (like with AF.S 35/1.4 or AF-S 24/1.4). And most of that half a stop of light happens already during the first third of a stop between f2 and f1.8, from then and onwards you get less and less increase of light for each third of a stop.
3. Compare the Nikon AF-S 85/1.4 with Canons 85/1.2: 660 grams and $1650 vs 1025 grams and $2200. There is almost half a kilo extra glass and $650 to get that extra 1/3 of a stop which do not really give any extra light ... And the Canon 85/1.2 focuses at lot slower to boot (all that extra glass to push around).
4. One can argue the extra 1/3 of a stop would make a difference in out of focus rendition ("bokeh"), but compared with f1.4 that difference must be very, very subtle at best.
The simple truth is if Canon had instead made a f1.4 version of their premium 85 mm lens, it could have been several hundred grams lighter, several hundreds of dollars cheaper, and faster focusing. And still had the same fine performance.
The most significant effect of that 1/3 extra stop is for marketing and bragging rights. For practical photography it has negligible positive effects.
Cytokine
Leading Member
whoosh1
Senior Member
Other than hearsay.
Grevture
Senior Member
Take a look at this image and see how hard it is even with the wider EF mount ...
The rearmost lens element is so large the contacts has to invade into it.
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I don't suffer from insanity, I enjoy every moment of it!
By the way, film is not dead.
It just smell funny
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whoosh1
Senior Member
Think this is an internet myth.
Teak
Well-known member
They do for the CX (Nikon 1) mount 
http://www.nikonusa.com/en/About-Ni...ry/Photos/h8c3r8pm/1-NIKKOR-32mm-f%2F1.2.html
http://www.nikonusa.com/en/About-Ni...ry/Photos/h8c3r8pm/1-NIKKOR-32mm-f%2F1.2.html
whoosh1
Senior Member
No text.
clarnibass
Senior Member
Maybe... but it is very clear from that photo that the rear lens in Canon's version is bigger than the Nikon mount and would be impossible. Whether Nikon can make an f/1.2 lens with a significantly different design that would use a samller rear lens, or whether it's even possible (maybe 85mm f/1.2 simply requires this size of lens), I have no idea.
whoosh1
Senior Member
I agree as sees from the photo that the design of Canon 85mm f/1.2 has a wider rear element than the Nikon 85mm f/1.4D - but similar to what you said none of us here on this forum have any idea whether it would be possible to have a different 85mm f/1.2 lens design where you have a smaller rear element that would fit in Nikon F mount. However I see assertions by forum members as if they were a gospel - that the Nikon mount is too small for 85mm f/1.2 or an autofocus f/1.2 lens of any focal length. Similarly I don't know why the mount size does not matter for an 600mm f/4 lens (which should have 150mm aperture much larger than the mount size) and the larger aperture can be achieved with a larger front element for that lens - while the mount size matters for 85mm f/1.2 lens (70.83 mm aperture size) and the big aperture cannot be achieved using a larger front element.
From the picture (linked by Grevture) I would think that Canon took advantage of the larger mount size for their 85mm f/1.2 design - but if Nikon were to design it they would design differently taking their own mount size into consideration. I have not checked side-by-side but from the dpreview review of Nikon 70-200 f/2.8 VR II where they show the Nikon next to the Canon - it seems to me that the Canon 70-200 f/2.8 rear element is wider but the Nikon lens is longer. May be that is related to the mount size or may be it is just a different design - but definitely different dimensions (longer/narrower vs wider/shorter). I fail to understand why similar difference in dimensions cannot be present for 85mm f/1.2 if Nikon were to decide to make one.
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www.dpreview.com
BTW Canon 70-200 f/2.8 is 3.5 in * 7.8 in while Nikon is 3.4 in * 8.1 in.
Similar differences in dimensions:
Nikon 85mm f/1.8g: 3.1 * 2.9
Canon 85mm f/1.8: 3.0 * 2.8
Nikon 200mm f/2: 4.9 * 8.0
Canon 200mm f/2: 5.0 * 8.2
OK - peace - if folks want to believe Nikon mount is too narrow for f/1.2 lens - that's fine with me. However I find that assertion unsubstantiated and unconvincing.
Grevture
Senior Member
Some actually have an idea
Look, this "why is there no Nikon 85/1.2 discussion" has a tendency to pop up here at least every six months or so, and has done so for many years. The issue has been discussed in length many times, and some very knowledgeable people has been involved from time to time. And yes, the rear diameter of extremely fast lenses really is an issue. A big issue (pun intended).
To be very exact, it very likely can be done - technically speaking. But from a "what makes sense" perspective, it cannot without getting and extremely expensive design. What is meant by the statement "Nikon can't make a 85/1.2 for the F mount" more precisely means "Nikon can't make a 85/1.2 for the F mount that any customer outside military entities and well funded science organisations could afford". Technically you can build almost any optical design, but what is the point of building something so horribly expensive nobody could buy it?
It is not just an internet myth.
Nikon can however do for example a 50-60 mm lens with 1.2 without much trouble (and has done several such lenses). I do not think AF has very much to do with it - the focusing elements are most often not the rearmost ones anyway.
Not wanting to be rude, but I think you might want to read a little about lens design
To make an over-simplistic explanation: When you calculate the aperture size, it is the diameter looking from the front end that matters (where the opening indeed is about 150 mm in a 600/4). This is what is often referred to as the "entrance pupil" in optical discussions. But after the aperture you can quite easily shrink the optical path using the built in teleconverter already in place to keep the size down (or also the other way around, like with the Metabones Speedboaster).
The irony is that it probably could be easier to build a very fast longer lens then a 85 without getting a overly complex lens design - because by virtue of the longer focal length you have more optical path to play with.
The real clue in that image is the fact that Canon had to put their electrical contacts inside the rearmost lens element - they would not have done that unless they really, really, desperately needed that large diameter to make it work optically. So even the wider EF mount is problematic for a 85/1.2 lens. The F narrower mount is even more problematic.
Again, it is in reality not a matter of what can technically be achieved, but what can reasonably be achieved in a design who can be sold at a attainable price and at the same time produce a good image quality. Nikon probably could make also a affordable 85/1.2 - if they let the image quality slip. Or, Nikon could make a 85/1.2 that had good image quality - if they let the price slip. But who would want a crappy 85/1.2 or one that is frightfully expensive?
And the bigger issue here - for what reason? That 1/3 extra stop has almost no meaningful photographic purpose which make such a lens a bit of a non-starter anyway. Canon did it for marketing purposes and bragging rights. Nikon has wisely stayed out of that.
Look at the re-occurring 85/1.8 vs 85/1.4 discussions - where many point out the f1.8 version in practical terms deliver something like 90-95% of the usable performance of the f1.4 version at a fraction of the price. For some, the difference still is worth the money. But considering how expensive (and cumbersome, and slow focusing) a f1.2 version would be, and that it probably would deliver almost no discernible practical image quality advantage at all - it is practically pointless commercially speaking.
Grevture
Senior Member
Maybe, just maybe, it is because the CX mount have a significantly more design friendly diameter-to-sensor-size ratio?
As many has noted over the years since the 1 cameras were first introduced, the CX mount is very, very large in proportion to the sensor size. To a degree that we have had frequent speculations whether it actually could accommodate also a APS-C sized sensor. This is why (also modern) the Sony E mount is so big in relation to the APS-C sensor size - in fact so big E mount even can be used for full frame sensors. A larger lens mount generally makes the lens design a whole lot easier.
The F mount is a bit narrow in relation to a FX sensor size. That was a design decision made some 65 years ago that probably has frustrated many lens designers at Nikon over the years. It does make certain lens designs a lot harder then it would had been with a wider lens mount.
whoosh1
Senior Member
The bigger choice to me from Nikon's perspective is not if Nikon can make or not make 85mm f/1.2 at a reasonable price (may be it is possible - may be it is not possible and neither of us know) - but the following:Grevture wrote:
Look, this "why is there no Nikon 85/1.2 discussion" has a tendency to pop up here at least every six months or so, and has done so for many years. The issue has been discussed in length many times, and some very knowledgeable people has been involved from time to time. And yes, the rear diameter of extremely fast lenses really is an issue. A big issue (pun intended).Some actually have an idea
>> Some think they have an idea
To be very exact, it very likely can be done - technically speaking. But from a "what makes sense" perspective, it cannot without getting and extremely expensive design. What is meant by the statement "Nikon can't make a 85/1.2 for the F mount" more precisely means "Nikon can't make a 85/1.2 for the F mount that any customer outside military entities and well funded science organisations could afford". Technically you can build almost any optical design, but what is the point of building something so horribly expensive nobody could buy it?
It is not just an internet myth.
A) Canon can only charge $2200 for 85mm f/1.2 lens (which is also relatively new - 2006 release) - so Nikon cannot charge much different for their version of an 85mm f/1.2 lens.
B) Nikon makes an 85mm f/1.4 lens and charge $1650 and people buy it in reasonably good numbers - and possibly cheaper/easier to make than 85mm f/1.2 and probably selling more quantity (due to slightly lower price) than if it was f/1.2.
So option B makes financial sense from Nikon's perspective - especially if their customers are not screaming for the f/1.2 - instead being content & offering explanation that F-mount is too small to make a quality f/1.2.
Again that does not mean Nikon will have to have the same design where they really really desparately need as large diameter as possible of the rear element. The problem will have to be solved with a different approach - and I doubt there is likely to be a will at Nikon to find a way while Nikon 85mm f/1.4g sells sufficiently good numbers. After that source of buyers is exhausted (slowed down at least) I would not be surprised if Nikon comes out with a Nikon 85mm f/1.2 - till then folks will continue to post on internet fora (forums) assertions why it is not possible in an F-mount (similar to the way folks used to post why its not possible for Nikon to do a digital full frame SLR before 2006).To make an over-simplistic explanation: When you calculate the aperture size, it is the diameter looking from the front end that matters (where the opening indeed is about 150 mm in a 600/4). This is what is often referred to as the "entrance pupil" in optical discussions. But after the aperture you can quite easily shrink the optical path using the built in teleconverter already in place to keep the size down (or also the other way around, like with the Metabones Speedboaster).Not wanting to be rude, but I think you might want to read a little about lens design
>> Sure - but what you have explained below is not much more convincing proof either - till then its a speculation.
The irony is that it probably could be easier to build a very fast longer lens then a 85 without getting a overly complex lens design - because by virtue of the longer focal length you have more optical path to play with.
The real clue in that image is the fact that Canon had to put their electrical contacts inside the rearmost lens element - they would not have done that unless they really, really, desperately needed that large diameter to make it work optically. So even the wider EF mount is problematic for a 85/1.2 lens. The F narrower mount is even more problematic.
Agree on that point.
Agree on this as well - there would be no point of releasing such a lens (as I said before while there are plenty of willing buyers for 85mm f/1.4g.
brightcolours
Forum Pro
He has been explained before in other threads why the size limit of the Nikon F-mount does matter, and has been explained that his view of lens design is simplistic and that his silly idea of aperture size regardless of focal length has no meaning.
Yet he keeps on posting in these threads the same nonsense. So, best to point out he is writing nonsense, but educating him seems a lost cause. He will simply disregard any valid point.
By the way, the 55/58mm/50mm f1.2's from Nikon also filled out the F-mount, and left no room for the contacts. Probably a reason why no AF version has surfaced, and why the 50mm f1.2 Ai-S is still available .
Yet he keeps on posting in these threads the same nonsense. So, best to point out he is writing nonsense, but educating him seems a lost cause. He will simply disregard any valid point.
By the way, the 55/58mm/50mm f1.2's from Nikon also filled out the F-mount, and left no room for the contacts. Probably a reason why no AF version has surfaced, and why the 50mm f1.2 Ai-S is still available .
cosmicnode
Veteran Member
It look's almost as if the rear elements on both lenses are flat. could this be only a protective rear filter which would not actually be the required rear element diameter ?. Nikon has been known to add protective front filters as part of the optical formula of long lenses and the slip in filters are required at all times, effectively the last element. Lenses such as the 300f2.8 and 200-400f4 have these features. Just a thought, I know as much about lens design as most people here.
whoosh1
Senior Member
Why can't we all be friends without having to litter many posts with "you speak nonsense"? Just a few examples from you (in many different dpreview.com fora - Canon, Nikon, Olympus, etc.):
"That is nonsense": http://www.dpreview.com/forums/post/51269345
"Nonsense": http://www.dpreview.com/forums/post/51243994
"Nonsense": http://www.dpreview.com/forums/post/50886819
"Still nonsense": http://www.dpreview.com/forums/post/50469809
"Nonsense": http://www.dpreview.com/forums/post/50460542
"Nonsense": http://www.dpreview.com/forums/post/51022553
"Lots of nonsense being written": http://www.dpreview.com/forums/post/51174483
"Nonsense": http://www.dpreview.com/forums/post/50996363
"Yay more nonsense": http://www.dpreview.com/forums/post/42194443
"That is just pure nonsense": http://www.dpreview.com/forums/post/34315353
The following query on google returns the max number of hits that google displays in their search results: "site:dpreview.com brightcolours nonsense" - which is just an indication on how many times you have put down others with the word "nonsense". You may be right (or may not be) - however please start being civil and express disagreements with less strong words and less arrogantly. Would you be saying "your point is nonsense" so many times in person rather than under the anonymity provided to you by the internet? If yes - I wish those in your contact some patience & peace.
Grevture has been making good points & good photo to prove his point and I acknowledge them - while not being fully convinced that the Nikon F-mount is so small that it cannot have an f/1.2 autofocus lens (albeit different design than the Canon version). I have also agreed to some of the points. He also has rightly stated/agreed that it may be possible to make an 85mm f/1.2 lens in the F-mount - but may be too expensive to be worth it.
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str8pipe
Forum Enthusiast
It makes sense for my thought process. I would stick with the f1.4 also vs price, weight and the small advantage of 1/3 of a stop.
I'm sorry if this was asked before, I'm a long time reader and post rarely but I did do a search on this before posting. Just curious.
Thanks for all the replies
I'm sorry if this was asked before, I'm a long time reader and post rarely but I did do a search on this before posting. Just curious.
Thanks for all the replies
Michael Benveniste
Veteran Member
I don't know if any f/1.2 AF lens is feasible in Nikon mount, but I'm more uncertain that an 85mm f/1.2 would be less feasible than a 50mm f/1.2. The "front focal length" determines the minimum needed size of the front element group, but when it comes to the rear element size the back focal length is of vastly more importance. That's in part why rangefinder cameras have smaller lenses than SLR's.
Recent patents for fast Nikon lenses like the 28mm f/1.8 show a back focal length of 38mm, give or take a tenth. I may be using the wrong formula, but to illuminate the corners of an FX frame at f/1.2 from that distance would require a rear element of at least 38.1mm of usable optical diameter, and from what I can tell the pin arrangement limits things to 37.5mm. So it's a very near thing.
As I've hypothesized before, if Nikon came up with an alternate "out-of-mount" way for the camera and lens to communicate they could make f/1.2 lenses. A couple of patents have hinted at this, but I've seen no evidence of it being real.
I do know is that Nikon and 3rd party lens makers have had 25+ years to make an AF f/1.2 lens in Nikon mount and so far all we've seen are designs on paper. I also know that Canon made a 50mm f/1.0L lens but discontinued it. It may be that market forces explain the lack more than physics.
Recent patents for fast Nikon lenses like the 28mm f/1.8 show a back focal length of 38mm, give or take a tenth. I may be using the wrong formula, but to illuminate the corners of an FX frame at f/1.2 from that distance would require a rear element of at least 38.1mm of usable optical diameter, and from what I can tell the pin arrangement limits things to 37.5mm. So it's a very near thing.
As I've hypothesized before, if Nikon came up with an alternate "out-of-mount" way for the camera and lens to communicate they could make f/1.2 lenses. A couple of patents have hinted at this, but I've seen no evidence of it being real.
I do know is that Nikon and 3rd party lens makers have had 25+ years to make an AF f/1.2 lens in Nikon mount and so far all we've seen are designs on paper. I also know that Canon made a 50mm f/1.0L lens but discontinued it. It may be that market forces explain the lack more than physics.
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