Fuji X-T2 announced

[Akira]

The best UI can be different from person to person.  The basic camera set up (shutter speed, aperture, ISO, the remaining frames as well as the exposure compensation) can easily be seen on the LCD in the modern DSLR design, too, albeit not in the same way as in the film camera design.

By the way, do you need to set the ISO value manually by 1/3 steps?  Also, you have to set the shutter speed using the command dial anyway to go below 1 sec. or to set it by 1/3 steps.

[bjornthun]

I think we should be happy that different manufacturers follow different paths w.r.t. user interfaces, since then perhaps more people can get a camera he or she really likes and can use creatively, with or without "space on the left side".

[pluton]

The best UI can be different from person to person.  The basic camera set up (shutter speed, aperture, ISO, the remaining frames as well as the exposure compensation) can easily be seen on the LCD in the modern DSLR design, too, albeit not in the same way as in the film camera design.

By the way, do you need to set the ISO value manually by 1/3 steps?  Also, you have to set the shutter speed using the command dial anyway to go below 1 sec. or to set it by 1/3 steps.

Curiously, my D800/E,  recent, fairly high-end cameras, cannot show me both the frames remaining AND the set ISO in the top annunciator panel. Hmmm...
I know you asked Bjørn this, but I recently realized that not once in my entire history of possessing digital cameras, now almost ten years, have I ever set the ISO in between the standard full doubling/halving values, ie: 100/200/400, etc.

[pluton]

It is worth noting for other people that Zeiss' data sheets give data for radial distortion, while Imatest and other test systems use TV distortion, which is a related (and generally better) measure: Zeiss' 2% is not the same as the 2% you see in lens reviews. 

The Zeiss habit of graphing the distortion along the image from center to edge makes sense to me.  One can clearly see that many wide (Distagon type) lenses have more distortion at 2/3 out than they have at the edge.  My lack of engineering or high geometry education prevents me from understanding how giving an overall percent figure without graphing it by location is more useful.

[Akira]

Curiously, my D800/E,  recent, fairly high-end cameras, cannot show me both the frames remaining AND the set ISO in the top annunciator panel. Hmmm...
I know you asked Bjørn this, but I recently realized that not once in my entire history of possessing digital cameras, now almost ten years, have I ever set the ISO in between the standard full doubling/halving values, ie: 100/200/400, etc.

Keith, your answer would be as highly appreciated as any experienced photographers.

If I remember correctly, the info structure on the LCD screen on the top cover of Nikon DSLRs was changed in the D7200/750 generation.  The display of P, A, S, M settings is gone and instead we can see "both" the ISO and the number of the remaining frames.  The full setting info can be seen only on the rear LCD screen by pushing the "info" button.

[Bjørn Rørslett]

For what it's worth, I very often use the 1/3 EV stops for ISO.

[Akira]

For what it's worth, I very often use the 1/3 EV stops for ISO.

On Df?  Could you elaborate the situations?

[Bjørn Rørslett]

Nothing to elaborate, Akira. I just prefer this approach.

[Les Olson]

The barrel distortion of the XF 35/2 WR can easily be observed in PhotoNinja, which as already mentioned, does not autocorrect distortion. I would never call such an amount of distortion insignificant. Both the 23/1.4 and the 14/2.8 do not show any significant distortion in PhotoNinja at all.

In other words, the low distortion figures for both the 14 and the 23 are most probably the true optical distortion figures.

The relationship between lens symmetry, distortion and peripheral light fall-off has been known since the 19th century.  So if Fuji have done what you suggest they have discovered a new principle of optics, which they have never patented but which no one else can work out how to copy although anyone can buy the lenses and take them apart and see how it is done.  Anything is possible, but that has to be low on the likelihood scale. 

[Bjørn Rørslett]

A little off topic, but possible relevant: what if Fuji has utilised the Slussarev method and introduced coma into the pupils? That would reduce vignetting and based on experience from the (earlier) wide Nikkors using this approach, one can have reduced vignetting and very little barrel distortion.  In this case the price to be paid is of course the necessity of adding more elements to do a downstream correction for the introduced aberration.

Owners of these Fuji lenses could observe the themselves  by looking into the lens (front or rear) well stopped down, to see whether the pupil shape alters off axis. My 15 mm Nikkors (f/3.5, f/5.6) both show this effect very clearly. The newer Nikkor 14 mm f/2.8 does not.

[bjornthun]

Google turned up this (and more) on Slussarev: http://photo.net/large-format-photography-forum/00I1bL

Slussarev's method has been used by Zeiss, Nikon, Rodenstock et al., read the third or fourth post in that thread.

A side note here may be the Russar 20mm f/5.6 wide angle design, by Russinovich. That lens has actually been re-issued by Lomography and Zenit Krasnogorsk.

[Les Olson]

Google turned up this (and more) on Slussarev: http://photo.net/large-format-photography-forum/00I1bL

Slussarev's method has been used by Zeiss, Nikon, Rodenstock et al., read the third or fourth post in that thread.

A side note here may be the Russar 20mm f/5.6 wide angle design, by Russinovich. That lens has actually been re-issued by Lomography and Zenit Krasnogorsk.

According to both Rudolf Kingslake and Hubert Nasse (http://lenspire.zeiss.com/en/wp-content/uploads/sites/2/2015/09/en_CLB41_Nasse_LensNames_Distagon.pdf) the design was invented by another Russian, Roosinov (or Roossinov), and later became the Zeiss Biogon and the Schneider Super-Angulon.  It is symmetrical, and has a large negative element at both ends, so both the entry and exit pupils are enlarged at oblique angles, and because of the symmetry there is no distortion (the design was intended for aerial reconnaissance cameras).  A lens with a large negative front element but not a large negative rear element will show the effect for the entry pupil but not the exit pupil (Kingslake illustrates this with Nikon's 8mm fisheye), and will have a lot of barrel distortion because of the extreme asymmetry - which also contributes to uniformity of illumination.

According to Nasse peripheral light fall-off in Distagon-type designs is due mainly to mechanical vignetting by the mount, which is why it clears as the lens is stopped down.  In symmetrical lenses like the Biogon smaller apertures have little effect.

[Bjørn Rørslett]

A fisheye lens is all about barrel distortion of course. It is also very efficient in terms of the fraction of incoming light actually ending up at the film plane. Thus evenness of illumination is no surprise.

I looked closely on my 15 mm Nikkors and their clearly show the most pronounced enlargement of the entrance pupil. Whatever changes taking place in their exit pupils are much more difficult to observe. They are highly retrofocus optics with huge negative front elements and also show very low barrel distortion (at distance). Very nice lenses for architecture they are.

Up close, their CRC design introduces substantial barrel distortion, just like with the 35/1.4 to name another lens sharing this behaviour.

[bjornthun]

Les, we are talking about the same man, I got the "-ich" at the end of name wrong. Properly transscirbed from Cyrrilic it is Rusinov. More about the original Russar, http://microsites.lomography.com/russar-lens/history/

[Akira]

Nothing to elaborate, Akira. I just prefer this approach.

Okay, this would be my last question for this particular topic.  Do you like to change ISO value for the exposure compensation or for the intentional over/underexposure rather than tweaking the dedicated exposure compensation dial?