Author Topic: Fooling around with a Noct-Nikkor  (Read 1859 times)

David H. Hartman

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Re: Fooling around with a Noct-Nikkor
« Reply #15 on: April 20, 2017, 23:55:34 »
What is the size of a single pixel for a D800 censor? After the Bayer filter does its thing what is the "size" of a single pixel in the image file? Is it the size of four pixels, a red, two green and a blue?

What circle of confusion should be used for 100% pixel peeping? :D

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Airy

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Re: Fooling around with a Noct-Nikkor
« Reply #16 on: April 21, 2017, 00:07:55 »
Vast subject, worth another thread. In the present case, I only can say that the Noct dislikes high MP sensors. My subjective impressions (when it is properly focussed) is that Noct IQ wide open ranges from "remarkable" to "junk". I still do not understand how the 50/1.2 plays it even with the Noct when the D800 is behind, whereas on Df, I would immediately know my preference.

... to be taken with a pinch of salt, since I have only a few hundred shots done and none at night. I hope to be able to propose "comparative" shots, which is tricky because I'd have to change my vantage point (if some nifty fifty were used as a yardstick), to keep the framing identical (an thereby altering the perspective and possibly the lighting).

As for handling, the Noct is a pig. Focus shift, shallow DOF and short throw = no fun. Fortunately, weight and form factor are ideal on Df. If you want to stay comfortable, go for a Voigt 58/1.4, my sweetest lens so far.
Airy Magnien

simsurace

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Re: Fooling around with a Noct-Nikkor
« Reply #17 on: April 21, 2017, 09:34:21 »
Although I can understand the appeal of statistical shooting, I would like to humbly relate that I've been following an approach that is quite different.
I don't know whether it will work for everyone, but I believe that manual focus can be trained similar to throwing darts or basketballs, or playing an instrument.
You have to force yourself to get it right on the first try.
I did and still do the following practice method.

Pick a very fast shutter speed to make it just about the focus (like 1/1000s).
I stand with my camera in front of my belly, arms relaxed and my left hand on the focus ring. I put the lens on infinity between shots to have a consistent starting point.
I pick a target (for starting out, targets on an inclined plane like a bookshelf at an angle or an isolated target like a sharp pencil in a mug are best), I look at it and try to concentrate on its appearance. I then raise my camera to the eye while inhaling, and while exhaling I turn the focus ring in one continuous motion (no overshoot because that is too difficult for the brain, at least mine), stop and press the shutter. Then I lower my camera again, inhaling and exhaling, before doing the next turn. The whole cycle lasts 2-3 seconds only. I do five of the same target, then calmly evaluate the results. Afterwards, I go to the next target, picking a nice variety of focus distances between MFD and a few meters (for close to infinity focus I do rely on the green dot, otherwise I try to ignore it and concentrate on the visual appearance of the target). I will do no more than 5-10 targets a day, and then do something easier for the rest of the day (like shooting at smaller apertures and work on composition and exposure).

The method has the advantage of not straining the eyes so much because they can relax between the shots, while standing there turning the focus ring back and forth around is very tiresome for the eyes, and small differences are harder to perceive than a continuous focus action. You benefit from observing the target with your naked eye and having a short-term memory of it when you see it again through the viewfinder. Your brain learns how much to turn the ring based on the distance (if you prefer, you can also start from MFD all the time). You maintain a healthy breathing cycle and a relaxed stance, both of which make the whole thing more enjoyable, while also giving you a stable platform for slower shutter speeds. You also train yourself to be quick, which is handy for street and portrait shooting. Because you are not overshooting while turning the ring, you will learn to have a sense of the degree to which you missed focus even without looking at the image (like when throwing a ball, you usually know that it will miss as soon it leaves your hand, so over time you will be confident that it hits once it leaves your hand).

It's not that trying to nail focus by going back and forth is bad in itself or cheating, but I find that I'm not able to train myself to get better that way (essentially, it's an open control loop and you never have to make a commitment). I will reserve this for the really hard targets, but while practising I try to make one continuous turn and then stop.

If you try this, I would be interested to hear about your experiences.
Simone Carlo Surace
suracephoto.com

John Geerts

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Re: Fooling around with a Noct-Nikkor
« Reply #18 on: April 21, 2017, 16:43:46 »
As for handling, the Noct is a pig. Focus shift, shallow DOF and short throw = no fun.
Lenses should be fun on all camera's, not?

Airy

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Re: Fooling around with a Noct-Nikkor
« Reply #19 on: April 21, 2017, 18:43:52 »
Lens handling fun obviously varies. What matters most is the result,, but.
Airy Magnien

John Geerts

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Re: Fooling around with a Noct-Nikkor
« Reply #20 on: April 21, 2017, 19:17:21 »
Yes I understand. Thanks for your detailed experiences with the lens.  That's why I asked.  ;)   I agree that results matter. It all depends also on your personal goals and shooting style.

David H. Hartman

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Re: Fooling around with a Noct-Nikkor
« Reply #21 on: April 22, 2017, 01:40:40 »
Funny how skyrocketing ISOs have been balanced by skyrocketing resolution demanding higher shutter speeds.  ISO 12.8k is nice, but gone are my days of shooting a 50mm at 1/50.

Down sample and you're covered. :)

Last night I was trying to find out the DoF for a 58mm lens at f1.2 with a subject distance of 1.5 meters for a D800 when view at 100% pixels. If my logic was correct (which is not assured) the DoF would be a touch less than 8mm total (about 4mm fore and aft).

Dave Hartman
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Re: Fooling around with a Noct-Nikkor
« Reply #22 on: April 22, 2017, 05:20:43 »
Down sample and you're covered. :)

Unfortunately, not quite. Camera shake will result in a loss of contrast. Downsampling will make the blur less apparent for sure, but the contrast will not be restored. This is what I observed with the D800 on my first day of usage - blacks would appear "less black".
Airy Magnien

Jack Dahlgren

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Re: Fooling around with a Noct-Nikkor
« Reply #23 on: April 22, 2017, 05:29:17 »
Wide open ALL my lenses have less contrast. Especially pronounced on f/1.2 and f/1.4

pluton

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Re: Fooling around with a Noct-Nikkor
« Reply #24 on: April 22, 2017, 07:36:33 »
Simone, thanks for reminding me to practice quick focusing. Many of my lenses have too-short  and non-matching focus throws, so I tend to forget.
Practice and familiarization with the lenses also helps with predicting and controlling the actual, deliverable depth of field much more that charts and tables.
I often, but not always, practice what Airy has coined as 'statistical shooting'.  Not only against my camera shake, but against subject movement. Combined with instant focus check via playback, it is one of the great economies of digital.
With a non-moving photographer and subject, the imprecision of the modern focusing screens seem to demand repeated racking back and forth before settling on the placement of the plane of focus.
 
Keith B., Santa Monica, CA, USA

armando_m

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Re: Fooling around with a Noct-Nikkor
« Reply #25 on: April 22, 2017, 18:13:09 »
My 55 f1.2 is not a noct but it sure is complicated to focus on the D800

I can only focus with liveview when done with a tripod, and it looks better if the liveview is done in video mode, than switch to photo before taking the shot
I second the comment about the patient model and a photographer retaking the use of a MF lens

I'll practice Simone method, about the speed: the weight of the 55 seems to help a lot , and I get less motion blur than with my other lenses
Armando Morales
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Airy

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Re: Fooling around with a Noct-Nikkor
« Reply #26 on: April 22, 2017, 22:13:05 »
Today's finding, using test charts : indeed, on Df (16 MP), the Noct is better than the Voigt 58/1.4. On D800 (36 MP), the reverse was true.

In other words, the Noct is the better lens on relatively low res sensors, not on high res.

I still struggle to understand why this is the case, but it corroborates by practical shooting experience: on Df, the Noct does not disappoint. It is, so to say, a high contrast, low res lens, but the latter weakness is simply not apparent when the pixel count is 16 million (on FX).

The test chart shooting confirmed the better contrast, similar (apparent) resolution, lower coma of course, and lower (less "technicolor") LoCA. The focus shift is there and, if uncorrected, the focus area chosen at f/1.2 - f/1.4 will drift backwards, to the extent that the chosen focus point will slightly be out of focus, with slight purple fringing revealing the back-focussing. But the phenomenon, while annoying, does less damage that on D800.

I think I'll keep this lens - I really like the way ot draws at f/1.2-f/2, better that the 50/1.2 I think (and wide open, there is much less overall haze, increasing the subject isolation). But I'll never mount it on the D800, and can only hope that Df successors won't pack many more pixels.

Best use case: portraits, definitely, where the extra 8mm of focal length are quite welcome. As said before, for night shots, the Tamron 45/1.8 makes more sense. Now I am going to search for the patient model.
Airy Magnien

Akira

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Re: Fooling around with a Noct-Nikkor
« Reply #27 on: April 23, 2017, 00:15:59 »
I've heard somewhere that Noct was designed to reduce the coma while somewhat sacrificing the resolution.  The resolving power of Ai(s) 50/1.2 is higher.

So, the resolution of the 16MP sensor may not high enough to reveal the weak point of Noct, as opposed to the 36MP one.
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David H. Hartman

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Re: Fooling around with a Noct-Nikkor
« Reply #28 on: April 23, 2017, 01:23:34 »
I've heard somewhere that Noct was designed to reduce the coma while somewhat sacrificing the resolution.  The resolving power of Ai(s) 50/1.2 is higher.


Coma near the edges of the frame is a fault of spherical 50-55mm f/1.2 and f/1.4 lenses wide open and generally cured by stopping down. The aspheric front element of the Noct is there to control the coma.

Various correction of aberrations can confict so too much correction of coma in a spherical design will increase another aberration to an unexceptionable degree. The Noct was designed for shooting at night at large apertures, f/1.2 to maybe f/2.0 where a spherical design displays significant coma. If the Noct isn't as sharp as the 50/1.2 AI/AIS at f/5.6 it doesn't matter. Its primary design consideration isn't for shooting at f/5.6.

As a non-owner with no training in optical design I'm probably typing trash but that's my humble understanding.

Dave Hartman
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Re: Fooling around with a Noct-Nikkor
« Reply #29 on: April 23, 2017, 11:02:40 »
I've heard somewhere that Noct was designed to reduce the coma while somewhat sacrificing the resolution.  The resolving power of Ai(s) 50/1.2 is higher.

So, the resolution of the 16MP sensor may not high enough to reveal the weak point of Noct, as opposed to the 36MP one.

The trade-off "resolution vs. coma reduction" is obvious, away from the center. Far sides never get sharp when the Noct is wide open, regardless of focus compensation.This becomes apparent when shooting a +/- flat subject at an angle, here for instance:
Airy Magnien