DX Mirrorless?

Apart from using current DX lenses via an adapter, is there any advantage in making a DX Z series DSLR?

 

I can't see Nikon ever making a whole new range of lenses, a kinda Mini-Z mount.

 

Bodies can't be made much small/slimmer ergonomically.

 

If so, how much longer is Nikon going to keep consumer DX users happy. Lens wise is still pretty poor.

 

There are good reasons (for now) for pros to want FX to continue, such as better AF.

 

Anyone think there's going to be a Nikon D550?

One of the things I don't like about DX SLR cameras is the smaller viewfinder image. With a live view display (viewfinder or otherwise), the composing image display size is not related to the sensor size other than aspect ratio.

 

Otherwise, the same advantages/disadvantages apply as DSLRs. DX format should provide greater DOF per given view angle and lens speed, smaller lenses, somewhat smaller bodies, some more noise or less ISO capability, and I would argue less delivered resolution, though in reality the image quality of DX vs FX does not seem to be large.

 

Sony and others have DX mirrorless bodies that seem to sell for what I think are high prices. I would expect Nikon to do a mirrorless DX if marketing thought it would be profitable or essential to long range corporate goals.

Edited February 25, 2019 by robert_bouknight|1

I prefer that they don't use the same Z mount for the DX format if they ever introduce the DX format.

I prefer that they don't use the same Z mount for the DX format if they ever introduce the DX format.

Given the size of the Z-mount, I tend to agree. DX Z-mount lenses would be unnecessarily large.

 

 

Apart from using current DX lenses via an adapter, is there any advantage in making a DX Z series DSLR?

Price?

Size and weight?

Sony has some DX mirrorless - though one can certainly argue about their ergonomics.

 

I can't see Nikon ever making a whole new range of lenses, a kinda Mini-Z mount.

Given that they are going to struggle rounding out the FX Z-mount lens system, I agree.

 

If so, how much longer is Nikon going to keep consumer DX users happy. Lens wise is still pretty poor.

Contrary to, for example, Thom Hogan who keeps wanting more DX lenses, I do believe that there are a sufficient number available (or FX alternatives exist) already. I do believe that at least the lower end bodies are generally purchased with the kit lenses and then maybe a wide-angle and a prime are added.

 

DX seems to max out at about 24MP - so with a 52MP FX sensor, parity is achieved (though most definitely not in price). The D850 "almost" includes a D500 - at more than twice the cost.

 

Anyone think there's going to be a Nikon D550?

Good question - the D500 could easily get some improvement via firmware update (d9 option that is available in the D5 and D850).

 

One of the things I don't like about DX SLR cameras is the smaller viewfinder image. With a live view display (viewfinder or otherwise), the composing image display size is not related to the sensor size other than aspect ratio.

Even a DSLR DX viewfinder image could easily be magnified more. Besides, I don't find the viewfinder image size of the D500 limiting at all. I do recall though the tunnel view viewfinder of the D70.

 

I do wish I had a crystal ball to look into Nikon's future (and Sony's as well). For the time being, I am going to stick with the A7RII and D810 as the newer versions (A7RIII and D850) offer some desirable upgrades but not enough to warrant the monetary outlay needed to acquire them (for me, others certainly do feel different on that issue). So even if Nikon came out with a D550, I am not sure there would be a compelling-enough reason for me to upgrade.

I have a trip planned for this summer, and won't be taking a backpack full of FX cameras, fast primes and fast zooms. This morning, I was looking at DX lens offerings.

 

Most DX lens needs can be filled by existing Nikon offerings, but I would be more tempted to assemble a DX kit if there were a small fast semi-wide DX prime available. I guess I could use the 20//2.8AFD I have, but a 16mm +/-F/2(ish) DX pancake would be nice.

Edited February 25, 2019 by robert_bouknight|1

I also was kind of fine using a D500 alongside a D810. While there are hardware changes I'd like, 90% of what I want from Nikon could be provided by a software update that I'd be glad to pay moderately for. I keep saying that, and I keep not having time, health or energy to write up the list (and I'll be working at home again tonight... this is not unrelated to my recent lack of Nikon Wednesday images); it'll happen in some happy day in the future when I get to relax.

 

is there any advantage in making a DX Z series DSLR?

 

Fuji and, historically, Samsung have gone into the upper 20MP range on APS-C. For reach, I see the merits - the D500 behaves a bit better than a subset of the D850, and for so long as signal has to travel across the chip, there's some merit in not having the periphery there. This applies also to speed, although as stacked chips get more stacked, it may be less relevant.

 

Mostly, though, price. Sensors are still expensive. Plus you can get a lot more movement out of the IBIS if you stick a small sensor behind a big lens (and it's easier to handle vignetting and so on - but that's why we have the Z mount in the first place). For so long as Nikon really want you to buy something that'll differentiate them from a smartphone, though, I'm not sure they'll be that keen on small sensors.

 

Canon have their M series, which is oddly incompatible with the Eos R mount. I don't know that they've given it much more attention than Nikon have to DX lenses, although probably more than Nikon did to CX.

As far as Nikon is concerned, the high-end DX buck stops with the D500. They had to be practically dragged into offering even that, kicking and screaming and protesting every step of the way. It proved a successful alternative to the D8xx for sports and birding, so Nikon will keep it around and perhaps offer an upgrade eventually. But chances of them fielding a mirrorless Z in DX format are practically zero: by the time they could engineer a mirrorless DX with the AF performance of the D500, the market will have evaporated (or merged into a high-res FX mirrorless with crop mode).

 

Advanced Nikon DX users primarily want long teles, most of which are pulled from existing FX lines: mirrorless versions of those are way down Nikon's list of Z priorities, so a DX "Z" body would be stuck with the same FTZ kluge as the Z6/7. Not many birders or sports pros would sacrifice the speed and integration of D7500 or D500 + AFS teles for a DX-Z + FTZ adapted AFS teles. At the low end, the rapidly-dwindling consumer DX market is extremely price sensitive: at the moment, there's no way Nikon can sell a DX-Z in the price range of a D3500. The notion that mirrorless bodies have less parts and are cheaper to mfr didn't play out quite like we expected: R & D expenses and new sensors with embedded AF pixels offset the alleged savings near term.

 

So Nikon will not jump in with DX-Z unless they see a dramatic surge in Canon M sales. That seems unlikely: Fuji owns (and earned) the premium DX mirrorless market. The investment required for a series of top-quality DX-Z primes (that will barely move at B&H) isn't an attractive prospect for Nikon (or Canon, really). Not nearly as attractive as cutting the legs off Sony's A7 FX system before it eats them alive: THAT, both Nikon and Canon are finally responding to in earnest. Whether they can claw back some of the market buzz Sony took from them remains to be seen.

So even if Nikon came out with a D550, I am not sure there would be a compelling-enough reason for me to upgrade.

That would be a reason for this cheapskate to upgrade..., to a used D500!:) It took the D850's impact on used prices for the D810 for me to buy my D810. In truth, I'm not at all sure what it would take to make another major acquisition appealing, at least for the foreseeable future.

I do not see the need for APS-C format much less a DX that uses the existing Z mount lenses. If a smaller package is desirable they should go all the way to M4/3.

A good friend recently bought the D 500, loves it and is getting great photos. After talking to him, I thought about it & compared with the D 7200. I found that the areas where the D 500 was rated superior were either things I never used - high speed bursts or GPS, or touch screen (which I find enormously annoying on my Kindle Fire). Only the focus points were interesting, but I've been focusing cameras in various ways for a long time.. That said, at some point in this Digital photo world you do need advance with the technology or have your gear obsolescent.

I enjoy the D500 for speed and its unlimited buffer and for the money the D7200 that I have had for a while still has the best image quality though I think the current image quality differences are moot. From an image making stand point Nikon is doing fine with its DX cameras and the truth is the D5600 and D3500 are bargains. I can't imagine a good affordable line of cameras ending anytime soon though it would be reasonable for there to be a transition to an affordable mirrorless DX system. Back when film ruled guys who I new who were serious sold plasma once a week to pay for a couple of roles of film (72 shots) and processing to support their habit. Now for well less than the price of a very basic N70 film body from the mid 90s a young person can buy a two lens DSLR DX kit without bankrupting his/her parents and shoot all day long for the price of waiting for the battery to recharge. The D500 really answered the call for me with respect to what I really wanted in a DX camera. It stays on a long lens. It will most likely evolve but for me will not take the place of the D850 or 800E or their future iteration for landscape. I have to give it to the gripped D850 for overall versatility. Anyway I would like Nikon to eventually go with a DSLR sized mirrorless camera that will balance with long lenses. Though fast long focal length lenses have gotten lighter and shorter they are still quite large and with current mirrorless camera design its like having a package of cigarettes on the end of a long lens. The body has to balance with the lens and that requires some size and mass. That could be with mirrorless FX or more affordable mirrorless DX. I am happy with my current quiver of DSLR bodies and lenses but I am still on the prowl for new stuff. The Fuji X100 F is an APC mirrorless camera that has caught my interest. My first digital camera are was a Fuji Fine Pix S2 Pro and I loved the color. It took my Nikor lenses. The X100F has a leaf shutter so you can shoot at high speed with a speed light without having to set the speed light on power consuming high speed sync. You can use it in the middle of the day to better control ambient light rather than using a neutral density filter. Its a small street camera that I think would be fun to use. Having the fixed permanent lens forces me to be creative and zoom with my legs. Anyway that may be my next body. Perhaps Nikon will come out with a DSLR sized mirrorless body with a leaf shutter rather than a focal plane shutter. That will peak my interest sooner than later. I am certain I will someday own one or more Nikon mirrorless bodies, but not yet. As well I think a DX mirrorless body might be an affordable alternative to take the place of DSLR Dx cameras and will put that many more cameras in the hands of folks with fewer resources. The image quality from APC cameras is really fantastic and will only improve regardless of what flavor, so I am hopeful for the future. Good hunting.

I enjoy the D500 for speed and its unlimited buffer and for the money the D7200 that I have had for a while still has the best image quality though I think the current image quality differences are moot. From an image making stand point Nikon is doing fine with its DX cameras and the truth is the D5600 and D3500 are bargains. I can't imagine a good affordable line of cameras ending anytime soon though it would be reasonable for there to be a transition to an affordable mirrorless DX system. Back when film ruled guys who I new who were serious sold plasma once a week to pay for a couple of roles of film (72 shots) and processing to support their habit. Now for well less than the price of a very basic N70 film body from the mid 90s a young person can buy a two lens DSLR DX kit without bankrupting his/her parents and shoot all day long for the price of waiting for the battery to recharge. The D500 really answered the call for me with respect to what I really wanted in a DX camera. It stays on a long lens. It will most likely evolve but for me will not take the place of the D850 or 800E or their future iteration for landscape. I have to give it to the gripped D850 for overall versatility. Anyway I would like Nikon to eventually go with a DSLR sized mirrorless camera that will balance with long lenses. Though fast long focal length lenses have gotten lighter and shorter they are still quite large and with current mirrorless camera design its like having a package of cigarettes on the end of a long lens. The body has to balance with the lens and that requires some size and mass. That could be with mirrorless FX or more affordable mirrorless DX. I am happy with my current quiver of DSLR bodies and lenses but I am still on the prowl for new stuff. The Fuji X100 F is an APC mirrorless camera that has caught my interest. My first digital camera are was a Fuji Fine Pix S2 Pro and I loved the color. It took my Nikor lenses. The X100F has a leaf shutter so you can shoot at high speed with a speed light without having to set the speed light on power consuming high speed sync. You can use it in the middle of the day to better control ambient light rather than using a neutral density filter. Its a small street camera that I think would be fun to use. Having the fixed permanent lens forces me to be creative and zoom with my legs. Anyway that may be my next body. Perhaps Nikon will come out with a DSLR sized mirrorless body with a leaf shutter rather than a focal plane shutter. That will peak my interest sooner than later. I am certain I will someday own one or more Nikon mirrorless bodies, but not yet. As well I think a DX mirrorless body might be an affordable alternative to take the place of DSLR Dx cameras and will put that many more cameras in the hands of folks with fewer resources. The image quality from APC cameras is really fantastic and will only improve regardless of what flavor, so I am hopeful for the future. Good hunting.

 

If you don't have much money and want a mirrorless you can get a Sony A7. It's less than $1000 with a lens.There is no need to go DX.

In truth, I'm not at all sure what it would take to make another major acquisition appealing

Eye-AF that works on animals and birds would certainly tempt me. I am not saying that for some the changes going from a D810 to a D850 aren't substantial - they just aren't sufficient for me to take the financial hit associated with that upgrade.

 

If you don't have much money and want a mirrorless you can get a Sony A7. It's less than $1000 with a lens.There is no need to go DX.

There are barely any inexpensive lenses available for the Sony A7 series - so what you save on the body will be more than made up for paying for the necessary lenses. For some applications, the A7 - despite its shortcomings - might be a better option; for others, any DX camera with access to a decent set of lenses might be preferable.

Edited March 2, 2019 by Dieter Schaefer

Yes Bebu but half of my Nikon children are DX and I love them all equally. They want a DX mirrorless younger brother.

The Dx is just a smaller less expensive sensor. Fuji already makes a terrific APS-C (DX) mirrorless camera.

Why wouldn't Nikon want some of that market? I can see completely silent Nikon DX and FX mirrorless cameras in the future with massive unlimited buffers shooting 20 frames a second the size of a D500 that sell for $50 for wild life photography. Other than the price I really believe we will see that some day. I would buy one and put it on the end of my long lenses to sneak up on unsuspecting grouse and weasels in North Dakota where I work. Stay frosty.

Why wouldn't Nikon want some of that market?

 

There are a number of companies who make APS-C or the slightly smaller Micro Four Thirds sensored cameras, and much of the DX market is very price-sensitive. Nikon judged that the full-frame mirrorless market is more profitable and so they focus on that, at least for the time being.

 

Since it's possible to show the DX image in the EVF of a full-frame mirrorless camera and use the whole viewfinder area for displaying the crop, there is probably not much benefit from making a separate high-end wildlife DX mirrorless camera, apart from the price. And Nikon would prefer to sell products that they can ask a high price for.

 

There is also the issue of having to make a separate lens lineup that at least covers the wide angle needs of potential DX mirrorless users. In DSLRs, a lot of people have been complaining about the lack of dedicated high-end DX lenses, though some users don't mind their absence. So far, there are no long lenses on the Z lens roadmap, so a high-end DX Z camera would then be without dedicated wide angle DX lenses as well as the (for the purpose) essential long lenses. If Nikon make such a camera, the time is after those lenses have become available.

Edited March 4, 2019 by ilkka_nissila

I have no independent knowledge, so the following is purely conjecture: I would not be surprised if Nikon has decided to get back to a single sensor format as the basis of their ongoing research and development, such as was the case before the advent of digital. Back then, they only had to develop lenses to cover a single sensor size, and offered both lenses and bodies with varying levels of technology and workmanship. So, my Nikkormat EL shared the same sensor (35mm film) as every other Nikon body, but was far less expensive than the Nikon F of the day, but could be used with both inexpensive and expensive glass. Seems a logical evolution that the Z7 and Z6 are the first fruits of a return to the high/low mix of bodies and lenses within a single format. Let's keep in mind that DX format was originally a waypoint along the path to full frame (or larger) sensors, dictated by the limits of available technology. That DX endures seems an unanticipated anomaly, particularly given the current sensor technology. For example, pixel pitch of the D500 vs. the D850 is within 3%, such that you can, at least theoretically, crop a D850 image to match a D500 image with essentially identical resolution. The previous benefit of the crop sensor, of having a higher pixel density for a given focal length, has been overtaken by events. Why would Nikon develop a D550, unless it is simply to fill a perceived, if illogical (on the part of buyers) market niche? It seems to make much more sense to go all-in with the new format, maintain backwards compatibility, and let the anachronistic DX line die a natural, if prolonged, death. I predict ongoing development of a high/low mix of bodies and lenses in the "Z" format, progressive diminution of investment in FF DSLR lines, and eventual abandonement of the DX line entirely. "You's pays your money and you's takes your chances."

make much more sense to go all-in with the new format

Err, do you mean 'old or maybe original format'...? ;)

 

Agreed, DX R.I.P. some time soonish...!

Edited March 4, 2019 by mike_halliwell

Err, do you mean 'old or maybe original format'...?

No, I meant "new", as in the Z-mount. The change to mirrorless, the shorter lens-sensor distance, and the larger mount diameter are a major and significant change that will have very long-term impacts on lens engineering and imaging options. We've heard many complaints over the years regarding Nikon's sticking with their "obsolete" F-mount for nearly 70 years, with all of the technical constraints imposed therefrom. Today, the actual net size of the sensor is almost immaterial, since it seems technology will ultimately allow whatever characteristics are desired to be engineered into the sensor. I'm almost surprised Nikon chose to stay with the FX sensor size, except, perhaps, in the interest of backwards compatibility and comfort in the marketplace.

Ah OK, I thought you meant format as in medium format, large format etc, ie sensor size.

 

I never saw the Z-Mount as a new format.

 

Same format, different mount for me.

 

I'm almost surprised Nikon chose to stay with the FX sensor size

There was a thread somewhere that pointed out the Z- mount is the same throat size as some common MF, that's Medium Format, cameras. I wonder size the image circle is?

Edited March 4, 2019 by mike_halliwell

I just found out that the Z mount has four bayonet flanges.

 

Nikon really are losing the plot. Four flanges! How needless.

There was a thread somewhere that pointed out the Z- mount is the same throat size as some common MF, that's Medium Format, cameras. I wonder size the image circle is?

 

Well, there's this. The only thing exactly the same (55mm) diameter is Contax N, which was 35mm. (I don't know much about Contax SLRs, other than the AX with the trick "focus by moving the film, not the lens" thing.) Mamiya 7 (6x7cm) is smaller, but I strongly suspect that expects highly non-telecentric lenses given the system's relative focus on wide angles. Bronica's S2 (6x6cm SLR) isn't much bigger.

 

If the lenses are designed decently, they may well not be putting out a much larger image circle than the 35mm sensor - other than enough to allow IBIS to work. Spare light inside the mirror box is not your friend. I suspect (with a limited understanding of optics) that the benefit of the wider and shorter mount is more to do with allowing a lot of light to reach the edges of the frame with some modicum of telecentricity, so you get less vignetting and probably better performance.

 

On the merits of smaller sensors:

• The speed at which data can be pulled off a sensor is related to the sensor size; this is why compacts and cell phones have had much less trouble getting to live view and 4K video. This problem has the potential to go away with suitably stacked sensors with more local read-out. There's a relationship between read-out speed and global shutter implementation, too. Absolute resolution also obviously has an effect (mostly once the data has got off the sensor), so the D5 is always going to have an easier life getting to high frame rates than the D850 - if the shutter could move fast enough and the limiting factor was pixel rate, the performance of a D850 indicates that a D5 ought to get near 20fps. If you want to use the DX crop of an FX sensor, you'll probably lose some speed relative to the native DX sensor.
  
• Pulling data across a sensor affects noise; this is partly size, partly resolution, but the D500 does behave marginally better than the DX crop of the D850 at the same ISO, probably for this reason. (This has generally been true of the D8x0 line.) Nikon's never really made something with D5-sized pixels purely for dynamic range, although that may be partly because they'll run up against the 14-bit raw format at some point. Stacked sensors may or may not help this.
  
• Bigger sensors run warmer (hence medium format backs with fans in them). This affects noise, but also battery life.
  
• Above all else, sensor cost is highly affected by size, and I suspect by something like the square of the area (if you double the area, the number of rejects almost doubles, and the raw material cost doubles, although how the number of rejects affects the price affects this a lot). FX sensors have always been expensive; they're certainly never going to be as cheap as a DX sensor.
  

Countering that:

• It's easier to build large electron bins in a large sensor (over the sensor as a whole, you'll get better dynamic range out of a bigger sensor at the same technology level).
  
• For equivalent shooting, you're generally at a smaller relative aperture on a larger sensor - and a lot of aberrations are heavily affected by relative aperture; shooting an 85mm f/1.8 on DX may give you just shy of a 135mm lens equivalent view, but the FX lens will probably behave better at f/2.8 than the DX one does at f/1.8. This is largely why the largest equivalent apertures are available in bigger sensor sizes.
  

But I absolutely do have a D850 that I'm prepared to use the DX crop of when needed (mostly to save buffer space when I don't need the peripheral areas). At one point I suggested that Nikon should make a sensor that was about 50MP density in the centre (matching the pixel density of the 24MP DX bodies) where lenses are good, but drop to D810 resolution at the edges. Lenses may be getting to the stage where that would be a bad idea for more reasons than trying to sort out the image processing.

 

As for lenses, if the pixel density is the same for the DX and FX sensors, telephoto isn't the issue - you can always crop, or use a teleconverter. A 300mm f/2.8 is bigger than a 200mm f/2.8 almost entirely because of the physical aperture size difference (equivalent apertures), not, mostly, because it's longer. See the 300mm and 500mm PF lenses, although one could argue that they "cheat" because of the PF element - but telephoto lenses have always been shorter than you'd think, by definition. It's why comparisons like the P1000's "3000mm" lens irritate me - since it's doing that at 16MP; I can get "3000mm" out of any lens I own if I crop it enough. Once you're fairly into the telephoto range, image circle tends to be less of a problem anyway - so a 200mm lens with FX coverage isn't so different from a DX one.

 

Wide angles are more interesting. The smaller the format, the smaller the lens can be - and it's not trivial to expand the image circle of a small lens (unless you trust your panoramic stitching a lot). If I don't need aperture, it absolutely matters whether you've got a 35mm lens that's actually 35mm or actually 23mm - it's why the Coolpix A or the X100 series vaguely fit in a pocket and the Sony RX1 series (mostly) don't (and, more so, why an RX100 really does go everywhere). Not having a fixed-size mirror box in the way, if you're not on an SLR, helps a lot here - whereas the telecentricity problems at the edge of the frame cancel out with sensor size and field of view.

 

So. If Nikon were to make a DX version of the Z mount, I think it would be for cheaper bodies and for smaller wide-to-mid lenses with moderate apertures. The danger is that this is exactly the area where cell phones are eating whatever of the market isn't currently occupied by the (even cheaper) 1" compact mid-ground. Can they make some money there? Sure - the established players (notably Fuji, who started out with the same wide-to-mid selection that works on a rangefinder) are doing it, and there's the micro 4/3 crowd below it, although it's decreasingly obvious how much size benefit you gain through that route. But if they want to stay as separate as possible from the market segment that's in most danger of getting eaten, I can see why they went for FX.

 

By all accounts Nikon were looking at both sensor sizes for a long time, so I doubt it's a clear-cut thing - and I suspect the state of the market over the last year or two (I actually don't know, but I doubt the micro 4/3 sector is growing much) may have pushed them to the high end. More profits per item there, although obviously fewer sales, but that may also mean less risk in setting up large production runs.

 

As for "why FX rather than something bigger" - adapted lenses (new and old). It's all very well making a new mount and letting people adopt medium format glass onto it, but that glass is nothing like as cheap or ubiquitous as old 35mm lenses.

 

Brain dump. Long day, felt due for one. :-)

Nikon really are losing the plot. Four flanges! How needless.

Makes me wonder what they're planning for, long term...

 

Keep in mind that four flanges means only a 90 degree engagement rotation, rather than 120 degrees. This could point towards a lot of things, including simply minimizing lens component interference with camera body features. A short stroke mount could be very nice.

Well, there's this. The only thing exactly the same (55mm) diameter is Contax N, which was 35mm. (I don't know much about Contax SLRs, other than the AX with the trick "focus by moving the film, not the lens" thing.) Mamiya 7 (6x7cm) is smaller, but I strongly suspect that expects highly non-telecentric lenses given the system's relative focus on wide angles. Bronica's S2 (6x6cm SLR) isn't much bigger.

 

If the lenses are designed decently, they may well not be putting out a much larger image circle than the 35mm sensor - other than enough to allow IBIS to work. Spare light inside the mirror box is not your friend. I suspect (with a limited understanding of optics) that the benefit of the wider and shorter mount is more to do with allowing a lot of light to reach the edges of the frame with some modicum of telecentricity, so you get less vignetting and probably better performance.

 

On the merits of smaller sensors:

• The speed at which data can be pulled off a sensor is related to the sensor size; this is why compacts and cell phones have had much less trouble getting to live view and 4K video. This problem has the potential to go away with suitably stacked sensors with more local read-out. There's a relationship between read-out speed and global shutter implementation, too. Absolute resolution also obviously has an effect (mostly once the data has got off the sensor), so the D5 is always going to have an easier life getting to high frame rates than the D850 - if the shutter could move fast enough and the limiting factor was pixel rate, the performance of a D850 indicates that a D5 ought to get near 20fps. If you want to use the DX crop of an FX sensor, you'll probably lose some speed relative to the native DX sensor.
  
• Pulling data across a sensor affects noise; this is partly size, partly resolution, but the D500 does behave marginally better than the DX crop of the D850 at the same ISO, probably for this reason. (This has generally been true of the D8x0 line.) Nikon's never really made something with D5-sized pixels purely for dynamic range, although that may be partly because they'll run up against the 14-bit raw format at some point. Stacked sensors may or may not help this.
  
• Bigger sensors run warmer (hence medium format backs with fans in them). This affects noise, but also battery life.
  
• Above all else, sensor cost is highly affected by size, and I suspect by something like the square of the area (if you double the area, the number of rejects almost doubles, and the raw material cost doubles, although how the number of rejects affects the price affects this a lot). FX sensors have always been expensive; they're certainly never going to be as cheap as a DX sensor.
  

Countering that:

• It's easier to build large electron bins in a large sensor (over the sensor as a whole, you'll get better dynamic range out of a bigger sensor at the same technology level).
  
• For equivalent shooting, you're generally at a smaller relative aperture on a larger sensor - and a lot of aberrations are heavily affected by relative aperture; shooting an 85mm f/1.8 on DX may give you just shy of a 135mm lens equivalent view, but the FX lens will probably behave better at f/2.8 than the DX one does at f/1.8. This is largely why the largest equivalent apertures are available in bigger sensor sizes.
  

But I absolutely do have a D850 that I'm prepared to use the DX crop of when needed (mostly to save buffer space when I don't need the peripheral areas). At one point I suggested that Nikon should make a sensor that was about 50MP density in the centre (matching the pixel density of the 24MP DX bodies) where lenses are good, but drop to D810 resolution at the edges. Lenses may be getting to the stage where that would be a bad idea for more reasons than trying to sort out the image processing.

 

As for lenses, if the pixel density is the same for the DX and FX sensors, telephoto isn't the issue - you can always crop, or use a teleconverter. A 300mm f/2.8 is bigger than a 200mm f/2.8 almost entirely because of the physical aperture size difference (equivalent apertures), not, mostly, because it's longer. See the 300mm and 500mm PF lenses, although one could argue that they "cheat" because of the PF element - but telephoto lenses have always been shorter than you'd think, by definition. It's why comparisons like the P1000's "3000mm" lens irritate me - since it's doing that at 16MP; I can get "3000mm" out of any lens I own if I crop it enough. Once you're fairly into the telephoto range, image circle tends to be less of a problem anyway - so a 200mm lens with FX coverage isn't so different from a DX one.

 

Wide angles are more interesting. The smaller the format, the smaller the lens can be - and it's not trivial to expand the image circle of a small lens (unless you trust your panoramic stitching a lot). If I don't need aperture, it absolutely matters whether you've got a 35mm lens that's actually 35mm or actually 23mm - it's why the Coolpix A or the X100 series vaguely fit in a pocket and the Sony RX1 series (mostly) don't (and, more so, why an RX100 really does go everywhere). Not having a fixed-size mirror box in the way, if you're not on an SLR, helps a lot here - whereas the telecentricity problems at the edge of the frame cancel out with sensor size and field of view.

 

So. If Nikon were to make a DX version of the Z mount, I think it would be for cheaper bodies and for smaller wide-to-mid lenses with moderate apertures. The danger is that this is exactly the area where cell phones are eating whatever of the market isn't currently occupied by the (even cheaper) 1" compact mid-ground. Can they make some money there? Sure - the established players (notably Fuji, who started out with the same wide-to-mid selection that works on a rangefinder) are doing it, and there's the micro 4/3 crowd below it, although it's decreasingly obvious how much size benefit you gain through that route. But if they want to stay as separate as possible from the market segment that's in most danger of getting eaten, I can see why they went for FX.

 

By all accounts Nikon were looking at both sensor sizes for a long time, so I doubt it's a clear-cut thing - and I suspect the state of the market over the last year or two (I actually don't know, but I doubt the micro 4/3 sector is growing much) may have pushed them to the high end. More profits per item there, although obviously fewer sales, but that may also mean less risk in setting up large production runs.

 

As for "why FX rather than something bigger" - adapted lenses (new and old). It's all very well making a new mount and letting people adopt medium format glass onto it, but that glass is nothing like as cheap or ubiquitous as old 35mm lenses.

 

Brain dump. Long day, felt due for one. :)

 

I don't want a bigger sensor with the Z mount either. Bigger sensor is good but make new mount. I want each format with its own mount.

Keep in mind that four flanges means only a 90 degree engagement rotation, rather than 120 degrees.

The F mount only rotates about 60 degrees for mounting as it is.

 

Just because there are 3 flanges, they don't have to rotate to the next flange position. In fact that would pop the mount right out of the next recess.

 

If a 4 blade bayonet was a good idea, don't you think another company would be using one already? A 45 degree maximum snap just seems a bit insecure to me. Not to say plain contrary when 3 blade bayonets have been almost industry-standard for decades.

 

"I don't want a bigger sensor with the Z mount either. Bigger sensor is good but make new mount. I want each format with its own mount."

 

Oh dear! Let's have each town and city invent its own weights and measures system too.

Edited March 5, 2019 by rodeo_joe|1

The F mount only rotates about 60 degrees for mounting as it is.

Right! Sorry, I was trying to picture it in my head and got confused. Oops. Still, the total area of mechanical engagement should be something approaching 50% in both cases, so I'm not sure why it's a concern.

 

Oh dear! Let's have each town and city invent its own weights and measures system too.

Now you're just casting aspersions! Just because something is a standard industry practice, but not interchangeable, does not mean it can't or shouldn't be changed for good reason. I don't pretend to know what that good reason might be. This would not be the first case where a manufacturer did something different simply so they could claim to be different from their competitors, particularly for mass market items. Still, Nikon seems to have made some very significant technical changes in the Z mount, and I hope/suspect they are for a good reason.

 

Edit: Sorry, RJ. I think I mis-read this versus Bebu's comment. My comment about 3 versus 4 flanges is still on point.