NIKON...MIRROR LESS NOW WITH FIRMWARE UPDATE

tc88

FT-1 should support full AF on all AF-S lens because they are electrical driven. That's pretty much all Nikon lens that are current. And I thought FT-1 has stop down lever for aperture control too?

The new adapter won't have mirror or any AF sensor inside. Whoever came up with the idea to incorporate those is beyond stupid. Engineering wise, if the image sensor can have enough AF information to determine the movement on the mirrorless lens, there is no reason why that's not enough for regular F-mount lens. The adapter is used to just pass the AF and aperture control from the camera to the lens, and also to bridge the flange gap.

Hiker

According to the home page, a rumor says the adaptor will be part of the kit, but the kit will be more money?? So, $3,000 for the 24mp 24-70 f4 kit PLUS add on an unknown at this time extra cost of an adaptor? I think I read it right. I hope Nikon does well (and I just bought an A7iii) and hit's a home run. We shall see. Looking forward to the reviews and commentary. Fun and exciting times!!

tc88

Bundling the adapter at minimum cost should be the right business decision at this time.

Symphotic

Adapter at no cost! Cool. I'm not excited about a 35 or 50 mm lens, so maybe I'll go with the kit zoom until a 28 mm and a Noct comes out.
Better sensor than the D850? Wow. The D850 has a splendid sensor indeed.
Standing by.

donaldejose

Rumor: "the new range of lenses will have fresnel elements to give an ‘effective’ larger aperture (so I was told a 1.8 will be marketed as 1.8 but behaves like a 1.4, and be tiny) much like their new 300mm that shrunk." Interesting, especially if the new f1.8 lenses are budget priced alternatives in their focal length like the old f1.8 lenses were. How about an 85mm f1.8 that behaves like an 85mm f1.4 without the additional cost and an 85mm f1.4 that behaves like an 85mm f1.2? Such new lenses may be as revolutionary as a mirrorless body and give Nikon a real market advantage.

manhattanboy

@donaldejose pf lenses are not going to be "budget" lenses. The 300 pf was not quite double the cost of the regular version. If Nikon is really going to make these all pf lenses, then the new mirrorless system is going to be very expensive. However, I think this is a real possibility as it would then give Nikon two product lines... Cheaper DSLRs for the non millionaire commoners and the new Z cameras for the Uber rich.

manhattanboy

@tc88 the lens is driven by the FT1, but it doesn't support the full AF array on the sensor or other features like automated tracking from the AF module. It is possible that Nikon puts out an adapter similar to Canon's EF-M where it is no where near as fast as a normal dslr could drive the lens but it technically works and will make you feel less like garbage from having all your lenses be immediately rendered obsolete.

tc88

AF-S lens are driven electrically. If the camera body can not AF with AF-S lens, it can not AF at all with any electrically driven lens including the mirrorless lens. After all, lens don't know whether an image is focused or not, and it's not related with any of the AF modes or AF sensors on the camera at all. It just follows the body's command to move back and forth and the body decides how much to move using its own calculations based on the values it got from AF sensors. On mirrorless, that will be the AF built on the image sensor instead of the separate AF sensor. Now if Nikon purposely degraded the FT-1 adapter (which wouldn't surprise me) because it's a lower end CX camera, that's a different matter. Engineering wise, degrading the performance purposely usually requires extra effort, but that's sometimes done for market segmentation purpose. That won't happen with the Z mount since it will want the new cameras to perform as well as they can to catch up.

Regarding the fresnel element improving F-stop, I think that's BS. The F-stop is determined by the opening. If the opening doesn't increase, the F-stop won't improve. The only way is to improve the T-stop, which is through better coatings to reduce transmission loss. But even the best T-stop possible is the F-stop value. You won't be able to go beyond that. Besides I doubt fresnel elements will reduce the transmission loss.

manhattanboy

Accordingly to the lastest video teaser the guy states he can use "all" of his F mount lenses. So hopefully that means that there will be full AF capability and not limited to the center point or some other stupid restrictions. That is great news for everyone!

Fingers crossed for a silent shooting mode.

Pistnbroke

All of "HIS " lenses may mean he has no screw drive ones like me

rmp

What does "effective f-stop" mean? Given the definition of "f-stop" as the size of an opening. What does "effective f-stop" mean?

My guess, from the context of it's use, the phrase "effective f-stop," would mean the new glass allows more light to get through the size of the opening that older glass.

HankB

The transmission efficiency of any modern photographic lens is into the 90s%. So comparing an "effective f-stop", or T-stop with the actual dimensional f-stop should give you a fairly insignificant, fractional f-stop difference.

tc88

The maximum light that can go into a lens is determined by the focus length (angle) and the opening. F-stop is already the theoretical maximum value. How much actual light gets in is called T-stop, (transmission-stop). However, a lens is typically quoted using a F-stop value. Doesn't matter whether the new glass lets in more light or not. If the opening is same, the maximum light that can come in is no better than the theoretical F-stop. So an F/1.8 lens will never let in light equivalent to F/1.4. That's just beyond physics.

mhedges

I guess that the argument is that the F1.4 has a (relatively) lower T stop than the F1.8, so in practice the difference in the amount of light transmitted is not that much.

Andrewz

1. f/stop is a mathematic formulation N=f/D (N=f/stop, f=focal length of lens, D=size of diaphragm aperture opening in mm).
2. T/stop is the actual measurement of light that is transmitted through the lens. Used for cine lenses, which makes a lot of sense.

Effective f/stop? I had to do a search. Used in macro photography when using extension tubes as you increase the distance to the focal plain from the rear element, light falls out the square of the distance (inverse square rule) really it's a T-stop. (https://www.scubageek.com/articles/tubes.pdf)

I'm thinking when using a "speed booster" with a smaller form factor sensor you could use the term effective f/stop in describing the amount of light that fits the sensor.

tc88

There is no such thing as "effective f-stop" since f-stop is already theoretical. Even with a "speed booster", the f-stop has changed because the focal length has changed.

As Andrewz mentioned, there is f (focal length), and D (aperture opening). When those two are fixed, the theoretical maximum light transmission possible is the f-stop value. So if f/D corresponds to 1.8, the lens will never take in any amount of light exceeding that.

tc88

People have to understand the main blog is a rumor site. As much, it takes anonymous submissions. There are people who will submit fake or their imaginations, or try to pull Peter's legs and have fun at that.

I have a hard time imagining that fresnel element will actually improve the light transmission considering all the edges it has.

Andrewz

@tc88 not sure what you're talking about, the f/stop or f/number is not theoretical, it's the ratio of the focal length divided by the aperture opening. i.e. a lens with a focal length of 50mm and an aperture opening of 25mm is an f/2.0 lens. Now this doesn't mean all f/2.0 lens allow the same amount of light through, hence the T/stop. There of course are other variables that effect light gathering and transmission. https://en.wikipedia.org/wiki/F-number.

@tc88 "So if f/D corresponds to 1.8, the lens will never take in any amount of light exceeding that." Not sure what you're trying to say here?

donaldejose

It was an eye-opening comment, wasn't it?

tc88

@Andrewz, "theoretical" means best possible limit, assuming you can design a lens with perfect transmission, no vignetting, etc. That's what the mathematical formula f/D says. Typically, a f/1.8 lens has a T-stop of about 2.2. But assuming you can design it perfectly, the best you can achieve is a T-stop of 1.8. Thus, F-stop is the "theoretical limit value" while T-stop is the "real" value.

Symphotic

Well, here is the question that is burning in my mind: When can we get a RRS L-Bracket? It might be nice if the bodies for the Z-6 and Z-7 could use the same L-Bracket.

WestEndFoto

About 45 days after they physically get a Z7, based on my experience with my D850.

Andrewz

@tc88 I think you misunderstand f/stops, not theoretical, not even best possible. It is simply the relationship between the focal length and the aperture diameter, nothing more nothing less, a mathematical fact.

Now I'd like to say that the f/stop has nothing to do with the amount of light that hits the sensor but that wouldn't be correct. All things being equal, meaning on one lens if I close down the aperture, less light will get through that lens. But different lens of the same focal length will have different light transmission. A simple design with fewer elements will transmit more light (probably with more distortion). Different focal lengths, different manufactures, different optic designs forget about, the amount of light that eventually hits the sensor will likely be different to some extent.

But, and here's the big but if manufactured correctly an f/2.8 is an f/2.8 because it's just the ratio between the focal length and the aperture, something that can be measured and calculated. An f/stop is not a measure of light transmission. You can also say the inverse of a T/stop, the focal length and aperture size don't matter because to find the T/stop you have to measure the amount of light coming through the lens. Of course there is a relationship but it's complicated.

So this is why the film industry uses T/stops, imagine mid scene cutting from a wide shot to a close up, you want the exposure to be exactly the same. Nothing worse than flicker in a shot. So cine lenses are built to closer tolerances and the light transition is measured for each lens. That why Cooke cine lenses can cost $40,000 each. Stills lenses just don't need to be that consistent.

The problem maybe in a hypothetical question like, "How much light does an f/2.8 lens let through?" The answer of course is no one knows. Throw it on an optical bench and test it then you'll know exactly how much light that lens lets through.

Okay done flogging that dead horse, I predict the Nikon mirrorless lens will have Z/stop. It's special light only Nikons can see ;-)

rmp

Thank you all for the help. I like the glass-less math models to get the F-stop numbers. But, I like the T-stop numbers even more. I like including the glass in the measurements of light hitting the sensors.

Given todays computing power, I see no reason that the older glass-less F-stop models could not be expanded to include new factors for the glass-lenses. I cannot help but wonder if that is what Nikon has done. I wonder if they have modernized the calculations for something like the T-Stop numbers.

While I am day-dreaming, I might as well go crazy. I wonder if "expanded, modernized", models couldn't calculate a "Z-stop" number that is the predicted amount of light hitting the sensor. At the same time, I wonder if the glass lenses couldn't be used for something like magnification or light amplification to make more light hit the sensor.

Oh well, two days to pre-orders. A month or so before the test begin.

mhedges

How do preorders usually go for this kind of thing? Is it one of those deals where they go up at a known time, and you have to keep hitting F5 and get your order in quick to get one? And do you have to put down a deposit?