Buy D850 or wait for its replacement

donaldejose

Good to hear from you on this Pistnbroke. I thought you used that lens. Backlighting is sort of a "trend" here. I don't like it either. I don't like the blown out hair and having to bring the shadowed face up. Normally I stop down all lenses one stop because that generally greatly improves their image quality although shooting at f1.4 is also a "trend" here. Two stops down is generally about where most lenses reach maximum sharpness. Since I was not the first shooter or the second shooter I was not posing people and just taking informal grab shots as I could. The day was quite overcast so there wasn't much light. The next time I find myself in this situation I will use f8 and Auto ISO. Going to f8 will probably improve IQ greater than a higher ISO diminishes it. Is that what you find?

Pistnbroke

I use base iso 200 which gives me iso 800 when I turn on the flash , group area always f8 unless its a dark 13th century church in December . auto iso 200-6400 I have not done a wedding with the D850 yet. I am still working to turn it into a point and shoot with all the dials taped up to combat the wifes wandering fingers ( ha ha ) but its main and possibly only improvement over the 810 is the auto focus and that will be for the feathered birds rather than the white dressed ones with no knickers (60% ). thank god I only have one wedding left, its just gone stupid with difficult customers . The number of times being wired has saved us from fake claims is frightening, And don't talk about corrupt wedding planners.
I did not think that photo was posed by a pro because the brides left hand is a bit funny . could have been brought across the front to hold the groom arm and show the ring.

donaldejose

Yes her left hand is funny. She was holding a replica of the superbowl trophy which her team, the Philadelphia Eagles, had just won. She was hiding that trophy from onlookers for a later reveal by holding it behind her. How many times are you going to run into that situation in a wedding! I was shooting at 300mm across a noisey running stream and could not even talk to her. No posing possible. LOL

Pistnbroke

LOL describes perfectly your situation...…………...

mhedges

Well it’s philly fans we are talking about here. I can’t say I’m all that surprised.

Pistnbroke

of course no body in the rest of the world knows what a Philly fan is …...

spraynpray

...or cares lol!

donaldejose

Philly Eagles fans become so emotional and so rowdy that the District Court opened a courtroom with judge in the stadium to handle fans arrested during the games so the police didn't have to transport arrested fans across town. You can imagine how they reacted when the team won the super bowl. Crazy people!

spraynpray

That's funny Donald!

PB_PM

American ‘football’ is crazy period, so no doubt about that.

WestEndFoto

donaldejose said:

WEF: You will have to judge that for yourself from the examples below. I found I was shooting mostly at 50mm so I could have used the Sigma 50mm lens for more sharpness. However, the first shot in the series of 25 per person had to be a mugshot with a model release so I zoomed in for that one shot. I shot from a tripod so I didn't have to hold a camera all day and I didn't want to move the tripod all the time so I used a zoom lens.

Donaldjose, I apologize for taking so long to get back to you. I have been meaning to get back to you but got busy in December - two weeks of travelling and then Christmas.

Those are great shots and very well shot with the 24-120. But I aspire to additional sharpness that only medium format can provide. For example, I looked at the 2nd and 3rd shot in detail, downloading a JPEG and pixel peaking. I would like to see the separation between the eyelashes and detail in the retinas. Also, you shot those at 5.6. I would like to see the sharpness that I am seeing wide open.

Given how diffraction works, it is theoretically possible to achieve that level of sharpness wide open (the wider the aperture, the less the diffraction) on FX. However, other aberrations make this in practice either technically impossible or cost prohibitive.

donaldejose

WEF: Yes, a larger medium format sensor in the range of 100 to 150mm would have the advantage of resolving detail better as long as the lens is up to the task. It would be bulky and more cumbersome to work with but that shouldn't be a problem shooting portraits in a studio off a tripod unrushed. I would like to have such a system but it would be cost prohibitive for me. Richard Avedon used an 8x10 view camera for his In the American West portraits and printed them larger than life size. I don't know if you could see the eyelashes crisp in those prints. But I do know the camera was far too bulky and cumbersome to use today. The 8xx series is the largest sensor I will ever purchase and a D4 or D5 size body that bulkiest body I will ever haul around to use. I hear rumors the D850 will eventually grow to 100 mp in future iterations but don't know if that is possible in an FX size sensor. I also hear rumors of a high megapixel D5 or D6 body but Nikon seems to have abandoned that idea after the D3x. I also don't know how far FX size lenses can go in sharpness with a 100 mp sensor. In the examples we are discussing I was very surprised the 24-120 did this well at f4 which is why I posted the images in the first place. It might to a bit better at f5.6 or maybe even f8 before diffraction reduces acuity but I suspect f5.6 would be the sharpest for this lens. I don't have the 24-70 f2.8 but that likely is sharper. I don't have any of the third part equivalent f2.8s because I don't trust their autofocus consistency for a day of shooting lots of people one after the other scheduled 5 minutes apart so you don't have time to check eye focus on every shot (and it would be soooo boring to do so). While the Sigma Art Series lenses are consistently sharper I also don't trust their focus consistency for fast paced work like this. So this is about the best I will be able to do in this type of situation. Perhaps the new S lenses are sharper (from my experience so far it seems so) and perhaps there will soon be a Z8 with two card slots (I would need two memory cards for a shoot like this because it is far too difficult to redo it) and perhaps Nikon will produce a S series lens in 24 to 120? What I really need for this type of situation is a very sharp 50 to 100 mm f4 or f2.8 lens. Maybe Sigma will make an Art series one with consistent AF I can trust. I wonder how sharp the Sigma Art 24-105 f4 lens is and whether the Nikon version has consistent AF?

mhedges

My guess is FX tops out at about 60 mp. That is the same pixel density as 24 mp DX.

mhedges

@donaldejose there is a 85mm 1.8 Z mount lens in the lineup for this year. That's probably as close as you will get to what you are asking for. It's pretty rare to see slower prime lenses these days, unless they are macro.

WestEndFoto

mhedges said:

My guess is FX tops out at about 60 mp. That is the same pixel density as 24 mp DX.

There is a theoretical maximum that depends on aperture. I will figure it out later, but it is well over 100mp and may be 200mp plus. However, we are talking a perfect optic at f/1.4. Practically, there are a whole host of aberrations at that aperture, so at the present level of technology, it is probably not economical.


When the 28 2.8 Ais came out in the early 80's, it was a big deal because it was diffraction limited at f/5.6, meaning it was as sharp at f/5.6 as diffraction would permit.

The new 105 1.4E looks like it is possibly diffraction limited at f/4.0 and in the centre, it continues to improve until f/2.8. And that is with current testing systems that are not very good at assessing performance past 40mp. As sensor resolution increases, this lens may continue to amaze.


So there is continued hope for increased resolution out of FX, but it will not be easy - or cheap.

spraynpray

Westie: Can you point me to some full res super-sharp MF images I can look at in detail please?

WestEndFoto

Not sure how much detail these have.

https://www.friedmanphoto.com/

Steven Friedman is a recent convert to Phase One. He is a local Vancouver photographer. I met him at a friend's gallery where he was showing his work. Phase One sponsored the event.


One of his most memorable stories was the three or four trips to New Zealand he took to capture a single scene just right. After all those trips, he finally captured what he wanted which was a foggy woodland scene. For his images, fog and wind are the variables that cause him to do reshoots. There must be zero wind because his photographs, while not "long exposure" per say, are long enough to be sabotaged by the slightest wind. So when you look at his woodland scenes, know that the leaves are sharp, as the image is rejected if the slightest breeze causes motion blur.


What sold me on medium format was standing inches away from one of his 90" wide prints and still seeing detail. Since Phase One was sponsoring the event, he was able to say what camera and lens he used (his older stuff was Hasselblad, which he also showed).


Regrettably, I don't have a link to a super high resolution image that shows detail like you might see on a Ken Rockwell or Photography Life example, but if one was motivated enough (I am not), I am sure it is out there.


I would be really happy if Nikon or Canon made a move into the medium format (and not cropped like Fuji or Hasselblad) market.

WestEndFoto

mhedges said:

My guess is FX tops out at about 60 mp. That is the same pixel density as 24 mp DX.

Mhedges, this will serve to illustrate "where FX might top out".

Go to the following sight.


https://www.cambridgeincolour.com/tutorials/diffraction-photography.htm#calculator

Go to the diffraction limit calculator and select advanced.

Set the following:
Resolution = 8 megapixels
Check "Set Circle of Confusion based on pixels.
Select f/22 for selected aperture
Press "Calculate"


"Diffraction Limited?" will return Yes.

This means that the limiting factor for sharpness at f/22 is diffraction, not the resolution of the sensor. A higher resolution sensor will not increase image sharpness.

Now select f/16 and select calculate. "Diffraction Limited?" will return No.

This means that at f/16, the sensor is now the limit for resolution and a higher resolution sensor will increase sharpness.


The sensor resolutions where increased sensor resolution will improve performance for various f-stops is as follows:


8mp - f/16

12mp - f/11

16mp - f/11

24mp - f/11

36mp - f/8

46mp - f/8

60mp - f/5.6

100mp - f/4.0

200mp - f/2.8

400mp - f/2.0

800mp - f/1.8

1600mp - f/1.2


So "where FX tops out at" is not a theoretical restraint, but an engineering and economic restraint. As long as lens designers can continue to reduce aberrations that become common at wider apertures, it will be possible to benefit from better sensors.

WestEndFoto

Further, to illustrate what is possible, I will draw your attention to the following site:

https://photographylife.com/reviews/nikon-105mm-f1-4e/2

which is a review of the Nikon 105mm 1.4E. Go to the MTF performance chart which Photography Life measured using Imatest charts and software.


Look how the sharpness performance continues to increase all the way to f/4.0. This is very impressive.


But what impressed me more was when I got it in my head that I was going to buy the Imatest charts and software myself and started corresponding with Imatest. What I learned was that their biggest charts (I think that they were six feet across, but I don't exactly remember) are only good up until about 40mp. You will also note that the Photography Life test is done 7 or 8 months prior to the release of the D850, so they were likely using a 36mp sensor.


I decided not to purchase the Imatest software and chart until they produce a bigger test chart, as I am only testing the chart, not the lens or camera. Even in the Photography Life review, with the 105 1.4E, they are likely testing the maximum resolution of the D810, not the lens.


So given what I know from the Cambridge in Colour website, Imatest and the Photography Life review, I suspect that the 105 and some of Nikon's other finest lenses will continue to benefit from increased sensor resolution.


But I suppose the provocative question is:


If Nikon went all out on lens design and produced the best 50mm lens they could and still sell for $10,000, how would it compare to a $10,000 non-cropped medium format lens of equivalent focal length (perhaps from Phase One).


And perhaps the reason that they have not done this is that it might require a 100-200mp sensor to obtain the full benefit of the lens. But if it competes at the Phase One level, we just might see lenses like this as sensor resolution increases.

tc88

I feel the need to say something. There is no way an 28mm lens becomes diffraction limited at f/5.6 while a 105mm lens becomes diffraction limited at f/4.

The diffraction happens when the aperture opening is small. However, 105mm f/4 has a much bigger opening than 28mm f/5.6. In fact, 105mm/4 is about 25mm which is same as 25mm at f/1. That's way bigger than any meaningful diffraction will ever happen.

So as a summary, talking about diffraction limitation with only the aperture value is totally meaningless. For example, a 500mm lens even at f/16 will not exhibit any meaningful diffraction.

I checked out the website that WFE referred. I can't find any mention of the focus length used. Maybe it's used somewhere in its calculation. But without mentioning it and obviously leading people to wrong conclusions, I call that web page BS.

WestEndFoto

tc88 said:

I feel the need to say something. There is no way an 28mm lens becomes diffraction limited at f/5.6 while a 105mm lens becomes diffraction limited at f/4.

The diffraction happens when the aperture opening is small. However, 105mm f/4 has a much bigger opening than 28mm f/5.6. In fact, 105mm/4 is about 25mm which is same as 25mm at f/1. That's way bigger than any meaningful diffraction will ever happen.

So as a summary, talking about diffraction limitation with only the aperture value is totally meaningless. For example, a 500mm lens even at f/16 will not exhibit any meaningful diffraction.

I checked out the website that WFE referred. I can't find any mention of the focus length used. Maybe it's used somewhere in its calculation. But without mentioning it and obviously leading people to wrong conclusions, I call that web page BS.

What you say is true if you hold the focal length constant and vary the format size. A smaller format will produce a smaller sensor area which will fit fewer airy disks. So the potential (diffraction limited) resolution is determined by the number of Airy disks.


Note the following excerpt:


The spread of the diffraction-limited PSF is approximated by the diameter of the first null of the Airy disk,
d / 2 = 1.22 λ N , {\displaystyle d/2=1.22\lambda N,\,}

where λ is the wavelength of the light and N is the f-number of the imaging optics. For f/8 and green (0.5 μm wavelength) light, d = 9.76 μm. This is of the same order of magnitude as the pixel size for the majority of commercially available 'full frame' (43mm sensor diagonal) cameras and so these will operate in regime 3 for f-numbers around 8 (few lenses are close to diffraction limited at f-numbers smaller than 8). Cameras with smaller sensors will tend to have smaller pixels, but their lenses will be designed for use at smaller f-numbers and it is likely that they will also operate in regime 3 for those f-numbers for which their lenses are diffraction limited.

which is from

https://en.wikipedia.org/wiki/Diffraction-limited_system

If you want to calculate the diffraction limited potential of a sensor, you are calculating the number of airy disks that fit on the sensor. The bigger the sensor, the more airy disks it fits. There is one shortcut in this website and that is wavelength. The longer the wavelength the smaller the airy disk and therefore the higher potential resolution. But I think that this effect does not change the overall point materially in practice.

You will see no mention of focal length for calculating the size of the Airy disk in neither the Cambridge in Colour article nor the Wikipedia article nor any other article that I can think of such as:


https://www.photopills.com/calculators/diffraction

https://photo.stackexchange.com/questions/8304/what-is-a-diffraction-limit

https://www.edmundoptics.com/resources/application-notes/imaging/diffraction-limit/

etc.

Here is a site that seems to imply that you are correct if not read carefully enough. It is a plain English description with no calculations. You will also note that it references the Cambridge in Colour site that you dismiss.

http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/diflim.html

WestEndFoto

tc88 said:

I feel the need to say something. There is no way an 28mm lens becomes diffraction limited at f/5.6 while a 105mm lens becomes diffraction limited at f/4.

Also, I need to clarify. My 35 year old 28mm lens is diffraction limited at f/5.6 while the new 105mm lens becomes diffraction limited at f/4.0 not because the focal length is different, but because the newer model (better optical design) lens has aberrations under better control which means that the aperture can be opened more before those aberrations begin to affect sharpness.

tc88

Lens aberration and diffraction are very different optical phenomena. Aberration deals with different wavelengths of light travel differently through same glass. Diffraction is about light bending at the edge of the opening.

The point is that 105mm can not possibly be diffraction limited at f/4 because the opening will be 25mm which is huge.

WestEndFoto

tc88 said:

Lens aberration and diffraction are very different optical phenomena. Aberration deals with different wavelengths of light travel differently through same glass. Diffraction is about light bending at the edge of the opening.

The point is that 105mm can not possibly be diffraction limited at f/4 because the opening will be 25mm which is huge.

Yes...…...but I don't understand your point. I am merely referring to the MTF chart in the Photography Life review. F/4.0 is the aperture with the highest resolution (centre). By diffraction limited I mean as the lens is further stopped down, the benefits to be gained by reduced aberrations are negated by increased diffraction, resulting in declining sharpness.

tc88

There can be multitude of reasons why a particular lens is sharpest at f/4, but for 105mm, diffraction is not one of them.

The designer may try to achieve higher sharpness at wider aperture such that the glasses are not optimal for narrower apertures and sharpness can be reduced.