The Close-Up Face of the Noct Nikkor

[John Koerner]

Apparently there is a slightly less field curvature in the AIS. Do note the Noct is not a flat-field design any way.

Bokeh might be a tad smoother with the AIS. Wide open no difference of course.

I doubt the differences, although can be shown, have any significant impact on the final outcome.

Interesting, thank you.

The Ai has double the focus throw, however.

Any advantage/disadvantage to this that you've noted?

Thanks again.

[Bjørn Rørslett]

Their price on the market is severely inflated due to collectors. Do not blame the lenses for this, though.

I got my Nocts for ridiculously low to very acceptable price though.

Also important to note that with many modern cameras one cannot properly focus such lenses, due to the groundglass of the finder being far too bright and fine-grained. The Df is pretty all right, though, and I will shortly install a darker and more coarse-grained screen into it.

[John Koerner]

Their price on the market is severely inflated due to collectors. Do not blame the lenses for this, though.

I got my Nocts for ridiculously low to very acceptable price though.

Also important to note that with many modern cameras one cannot properly focus such lenses, due to the groundglass of the finder being far too bright and fine-grained. The Df is pretty all right, though, and I will shortly install a darker and more coarse-grained screen into it.

You evaded my questions

Yes, when viewed through the viewfinder ... but using the LCD blown-up 10x I would imagine the focus would be even keener.

[Erik Lund]

The right amount of focus throw is very personal and different to focus length, system and focal length among others,,, So one singel lens is seldom right for everything, another reason many people here has many lenses of each focal length to choose from, not just to 'must have them all',,,,

Many of the Ai lenses are build with this, slower' longer focus throw that is nice especially for close-up work, These old Ai lenses have longer helical focusing threads so also more 'drag' to the focus feel especially with heave grease like #30 instead of #10 for instance.

[richardHaw]

i can second that.           
focus throw is a personal thing and will depend on the situation. (that is why i own several versions of some lenses)

shorter focus throw is great for street and documentary where subjects zip in and out so you want to be able to keep up. the bad thing about that is that you lose a couple of important markers for distances. as an example, the 35mm f/2.8 Ai goes from 1m-5m-infinity(i think). while it is OK and negligible to some people, to somebody like me, the missing numbers between 1-5m will make my focusing a lot less precise, so I bought a 35mm f/2.8 version that has at least a 2m and now i am happy with it for the fast pace street style (candid) that i do.

for studio and slow careful stuff, i would prefer the longer throw.

one thing that i do to mitigate any of these problems is having a lens with a long focus throw (55mm f/1.2 K) re-lubed with a much lighter grease. the reverse is also true for lenses with short focus throw (28mm f/2.8 Ai), I used a heavier grease so that i wont miss my focus while shooting on the street.

[Bjørn Rørslett]

You evaded my questions

Yes, when viewed through the viewfinder ... but using the LCD blown-up 10x I would imagine the focus would be even keener.

Not evading at all, just sticking to the facts. Sometimes there is not a simple yes/no answer to a question.

Unfortunately, LiveView is not always the answer for focusing accuracy. The image might dissolve into static noise when you really need to see the details. Even the much touted EVF of the Sony A7 series can fail badly with the Noct. I have tried under field conditions if you are puzzled about this observation.

[Michael Erlewine]

I have a question for Bjørn. When I have a lens like the Coastal Optics 60mm APO, which has a ridiculously small (for my work) focus throw, it was easier for me just to put the lens-camera on a focus rail where I have a longer focus throw via the rail. My question is:

What is the difference between using a helicoid on a lens and mounting a lens-fixed-on-a-camera on a focus rail and using that longer throw? My understanding is that the helicoid is better for stacking focus than a focus rail.

[Bjørn Rørslett]

The Coastal 60 has a CRC mechanism. Thus there is a difference in its optical performance when you use the focusing helicoid vs. putting the camera + lens on a focusing rail, the first being the better alternative. However, as the difference in actual magnification for your stacking purpose is likely small, and with the lens already focused to approximately the correct distance, the reduction in quality using the focusing rail should be small as well.

The real question is what method for focusing the stacking software deals with in an optimal manner. When I started with Zerene, I assumed that a fixed perspective would be optimal, thus kept the lens front stationary and changed extension, but that proved to be not so good option for the software. Fixed magnification and a change in perspective appears to be better. The last alternative, changing perspective *and* magnification concurrently, still has to be the least satisfactory.

[Michael Erlewine]

The Coastal 60 has a CRC mechanism. Thus there is a difference in its optical performance when you use the focusing helicoid vs. putting the camera + lens on a focusing rail, the first being the better alternative. However, as the difference in actual magnification for your stacking purpose is likely small, and with the lens already focused to approximately the correct distance, the reduction in quality using the focusing rail should be small as well.

The real question is what method for focusing the stacking software deals with in an optimal manner. When I started with Zerene, I assumed that a fixed perspective would be optimal, thus kept the lens front stationary and changed extension, but that proved to be not so good option for the software. Fixed magnification and a change in perspective appears to be better. The last alternative, changing perspective *and* magnification concurrently, still has to be the least satisfactory.

Yes,Rik Littlefield claims that the order of preference is (1) the best is bellows, moving rear standard, (2) is focusing the lens, (3) least best is focus rail. Thanks.