NikonGear'23

Gear Talk => Lens Talk => Topic started by: atpaula on November 15, 2016, 20:10:56

Title: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: atpaula on November 15, 2016, 20:10:56
AF-S 105mm f/1.4E , 105mm f/1.8 Ais and 105mm f/2.5 Ais.
All pics wide open, with no pp.

First pics with a D4s/tripod

(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD4S_5452_zpsiit4aylx.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD4S_5452_zpsiit4aylx.jpg.html)
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD4S_5455_zpszjdryhoa.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD4S_5455_zpszjdryhoa.jpg.html)
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD4S_5463_zps98tpve2e.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD4S_5463_zps98tpve2e.jpg.html)
and a Noct at a closer distance:
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD5S_4389_zpstyehnfgw.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD5S_4389_zpstyehnfgw.jpg.html)


D4s handheld:
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD4S_5453_zpsz2wtyx76.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD4S_5453_zpsz2wtyx76.jpg.html)
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD4S_5454_zpsh9n0jmmo.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD4S_5454_zpsh9n0jmmo.jpg.html)
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD4S_5459_zpsfuspdzom.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD4S_5459_zpsfuspdzom.jpg.html)
and a Noct at a closer distance and D5:
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD5S_4390_zpsab8316wi.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD5S_4390_zpsab8316wi.jpg.html)


D5 handheld:
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD5S_4402_zpsulvo2t7b.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD5S_4402_zpsulvo2t7b.jpg.html)
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD5S_4403_zpsdjlbqhyo.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD5S_4403_zpsdjlbqhyo.jpg.html)
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD5S_4400_zpssnkpdmnd.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD5S_4400_zpssnkpdmnd.jpg.html)


AF-S 105mm f/1.4E  x 58mm f/1.2 Noct at a closer distance, handheld D5:
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD5S_4396_zpsixjmmw6m.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD5S_4396_zpsixjmmw6m.jpg.html)
(http://i1011.photobucket.com/albums/af237/atpaula/atpaula005/aD5S_4391_zpsqlivvizy.jpg) (http://s1011.photobucket.com/user/atpaula/media/atpaula005/aD5S_4391_zpsqlivvizy.jpg.html)
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Bjørn Rørslett on November 15, 2016, 20:20:17
The tendency towards a "swirly" bokeh is quit visible for the 105/1.4E. However, not all subjects and scenes will show it this clearly.

The increase in background softness is largely dictated by the size of the blur circles, themselves in a direct relationship to the aperture size. No surprises there. However, I prefer myself the AI version of the 105/2.5 because of the curved aperture blades. The straight edges of the AIS blades can cause a more nervous character to the background, but of course this is not apparent with the lens wide open :D
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Tristin on November 16, 2016, 01:20:24
The 105/1.8 is certainly the weakest here.  It's bokeh really drops in quality as the distance to the background decreases.  Very evident in the first set, but fine in the others.  Has been my observation as well.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: atpaula on November 16, 2016, 12:15:02
Thanks Bjorn and Tristin.
I wish I could see more of these comparisons here.
BTW, I've just updated my website.
Please take a look t www.aguinaldodepaula.com
Thank you.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Akira on November 16, 2016, 12:55:23
Congrats on the renewal of your website!  It's nice to be able to browse through all your stunning images whenever I like.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: atpaula on November 16, 2016, 14:12:22
Congrats on the renewal of your website!  It's nice to be able to browse through all your stunning images whenever I like.

My pleasure Akira!!!
Send my regards to all japanese people, whom I miss a lot.
I can't wait to return to your country.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: stenrasmussen on November 16, 2016, 14:19:01
Thanks for this informative posting!
Interesting to see how the 2.5 renders the bright construction in the background with less outlining than the 1.8.
It would be interesting to see how the 1.8 behaves when stopped down.
...yes, the 1.4G is king of OOF meltdown...
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on November 16, 2016, 16:00:35
Just had a check - the fellow Xenotars (105/2.5, 105/2.8) are very difficult to tell apart on 3-D subjects, also regarding bokeh. It looks like the rear blur increases faster with the 2.8, owing to more pronounced spherical aberration when leaving the focus plave. The only noticeable effect (whe pixel peeping shots made with the Df) is that the green fringes produced by the 1.8 are more "concentrated", more narrow, with higher green colour saturation. This could mean more nervous bokeh.

Here is an example from which I drew the above conclusion. First the whole scene; the 1.8 shot (on the left) is slightly darker, by maybe 0.2 EV. Picture taken at f/2.8. Distance : about 2.2m. All illustrations are X/Y screenshots with X = left shot=  105/1.8; 100% crops except the general view.

Lower center: you'll see the green fringe difference on one cutlery element. Also, the letters on the bottle (already behind focus plane) have a more saturated black color on the left, while of course having fuzzy edges.
Right: the big letters on the milk bottle are slightly less fuzzy on the left pic.
Left: no significant difference can be seen on the wooden hedgehog. Near the top, there are two pale horizontal stripes on the left, merging to one on the right, so there is a tendency towards softer bokeh with the 105/2.5, but once again, I do not expect the differences (neither in bokeh, nor in sharpness) to play a significant role.

This is maybe why the Naerfoto website rates the 105/2.5 higher: similar results with smaller size and weight make the 105/2.5 more usable. The full aperture of the 105/1.8 (or even f/2.0) are not going to be useful very often due to high aberrations and noticeable bokeh outline - unlike for instance the full aperture of the Zeiss 135/2. One use case, also mentioned by Tristin, is night shots, where the full aperture is more usable than expected (low astigmatism, low bleeding), and the drawbacks (LoCA, low contrast, bokeh) a lesser issue.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on December 26, 2016, 09:18:40
I just had another run with now three oldtimers : 105/2.5 AI, AIS, and 105/1.8

No surprize ; they are as difficult as ever to tell apart. The field curvature of the f/2.5s is quite apparent at a distance of 2m (focus plane bent by maybe 4 cm at the outer edges), but whether that's relevant depends on your subjects.

Coming back to the bokeh, I am pleased, and not in the least surprized, to confirm that Björn is right - the AI is better at 2.8 (nearly circular defocused highlights) than both AIS versions (delivering heptagons and enneagons) ; there may be a slight advantage at f/4; beyond, the advantage brought by the rounded blades is negligible. Maybe I'll revise this opinion when shooting shiny motorcycles under blazing sunlight - wrong season.

The 1.8 bokeh is altered by mechanical vignetting at 1.8 and 2.0, apertures that are of limited use (also because of lower contrast and purple fringing).

Again, it seems like the 1.8 has slightly higher contrast, visible on textured subjects (e.g. fabric). Bottom line, if you have one of these lenses, and assuming it is in a fair condition, shoot and be happy. They are so close that owning more than one is essentially a collector's fad.

Evidence to follow.

P.S. sorry I cannot type Alt0224 on that laptop keyboard, so Björn gets the Swedish version of his first name.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Tristin on December 26, 2016, 17:37:37
They are so close that owning more than one is essentially a collector's fad.

I have disagree here strongly.  The field curvature of the f/2.5 limits it's use as a landscape lense heavily and it's poor handling of strong light sources in front of the lens (compared to the f/1.8 ) makes it a far worse lens for many uses.  I would not trust the f/2.5 to shoot live music, for example, as washed out images from stage lights would be the course for the night.

Btw, I copy/paste Bjørn's name as I am on mobile.  Easy  :)
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on December 26, 2016, 18:22:50
I just took the 1.8 for a walk after sunset, to check exactly this.

   Concerning landscapes, I do not usually shoot them wide open, but rather between f/4 and f/8. The sharpness drop due to field curvature did not spring to the eye, but I'll  check again.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Tristin on December 26, 2016, 18:28:42
I tend to shoot landscapes with the 105 at f/11, the field curvature in the corners of the f/2.5 is surprisingly strong.  Distant landscapes are fine, but closer elements in the corners sill suffer noticably.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on December 26, 2016, 18:38:17
This was not noticeable when I shot brickwalls at a short distance, although the field curvature is absolutely there, and well visible at f/2.5. Maybe your copy had an issue ? something like axial misplacement of some element (I suspect that was also the issue I encountered with a 50/1.8 AI I quickly returned). Xenotar designs are known to be especially sensitive to manufacturing tolerances.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on December 26, 2016, 19:48:59
Foreground lights : OK, no reason to complain. (105/1.8 at f/4)
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on December 26, 2016, 20:32:22
Here the announced evidence concerning bokeh. Shooting distance is about 1.5m. Camera : D800.
First pic : general scene.
Second pic : 2.5 AI and 2.5 AIS at f/4. This is the most I could get in terms of bokeh difference
Third pic : 2.5 AI and 1.8 AIS at f/2.8 ; ditto.
Fourth : same lenses at f/4. The difference becomes narrower, but the 1.8 retains sharper OOF highlight edges, also observed in an earlier post.
Fifth : same lenses ; the in-focus zone at f/2.8. The 1.8 is more contrasty.
Sixth : ditto at f/4; the f/1.8 retains a minimal advantage.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on December 26, 2016, 20:50:10
Now concerning the field curvature issue : first pic, shot at 5.6 with the 105/2.5 AI. Given the forward field curvature, you'd expect the top right corner to be significantly unsharp. Well, it is hard to judge given the subject, but that corner looks reasonably sharp.
Pics : full, center, top right, bottom left. All with Df.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on December 26, 2016, 20:51:49
Second series, with the 105/2.5 AIS, one year and a half earlier. Same details as above ; aperture was f/8.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on December 26, 2016, 20:54:09
Footnote : the processing (using LR) left default sharpness settings. Nowadays, I'd rather use Capture NX-D and higher sharpening settings (base setting = neutral, contrast +1, sharpness +7 which is +/- the limit before getting halos)
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Tristin on December 26, 2016, 22:43:52
Everything in this image that needs to be in focus is on a reatively slim focal plane, it would have to be some extreme curvature to exhibit here.  This is not an image the f/2.5 will struggle with.  The f/2.5 struggles in having objects in focus across a large focal plane.

Excuse the image hijack, but this is an example of the type of image the f/2.5 struggles with.  It was shot with the f/1.8 a f/11 I believe.  Had the f/2.5 been used, the building in the foreground certainly would have been oof still in the corners. 

I pulled this image from my instagram, so ignore any artifacts or whatnot.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on December 26, 2016, 23:12:42
Not sure how field curvature would reveal itself at f/11. The following is a comparative example of a shot taken at f/2.8, at a 2m distance.
First : overall pic
Second : right edge, 105/1.8; the book with the black cover (approx. in the same plane as the center book, on which the focus was set) is about sharp ; the writing on the yellow egg is fuzzy.
Third : right edge, 105/2.5 AIS; the writing on the egg is sharp, despite being approx. 4cm in front of the book backs; the writing on the black book is fuzzy.
Fourth : stopping down at f/8, and showing the right edge taken with the 1.8 (left) and the 2.5 (right). The effect of field curvature is +/- annihilated or, more precisely, the reference plane is in focus, while the egg is sharp (a bit better with the 2.5, no wonder).
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: PeterN on December 27, 2016, 12:17:59
Aguinaldo, thank you for the comparitive shots (also with other lenses). I am very impressed by your website and photos.
Airy, thank you for adding your comparisons as well.
Very helpful indeed!
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: atpaula on December 27, 2016, 18:13:22
Aguinaldo, thank you for the comparitive shots (also with other lenses). I am very impressed by your website and photos.
Airy, thank you for adding your comparisons as well.
Very helpful indeed!

My pleasure Peter.
I'm glad you like my work.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Roland Vink on December 27, 2016, 19:15:46
The field curvature of the 105/2.5 at close range (typical portrait distances) may be one of the reasons why this lens works so well for portraiture, as it helps to produce a softer, rounder background rendition.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Roland Vink on December 27, 2016, 19:23:16
Here the announced evidence concerning bokeh. Shooting distance is about 1.5m. Camera : D800.
Second pic : 2.5 AI and 2.5 AIS at f/4. This is the most I could get in terms of bokeh difference
This picture clearly shows the effect that the shape of the aperture has on bokeh, influencing the shape of de-focused highlights. However, since the lenses are optically the same, the correction for aberrations (especially spherical) is identical, so the smoothness of background and foreground rendition is the same.

Many reviewers make the mistake of assuming a lens will have good bokeh because it has rounded aperture blades. This is only partly correct, a lens may have a perfectly round opening but still have awful bokeh - harsh, nervous, double-lining - since the rendition of backgrounds is due to optical corrections, not the shape of the opening.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Akira on December 27, 2016, 20:11:25
What Roland says.  The problem with the Ai"s" Nikkors in general is that the aperture blades make very harsh, gear-like septagons or nonagons when stopped down by around one stop which make the out-focused point light sources ugly.  This was clearly presented by the images posted by Airy in reply #14.  And this is a bit annoying because stopping down by one stop is a preferable way to render the focused area sharper by keeping the shallow DOF.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Tristin on December 28, 2016, 05:59:23
The curvature "plunge" I noted on the copy of the Ai f/2.5 manifested distinctly in the extreme corners, and not the borders much.  As I crudely drew on these examples.  With the example of the buildings, f/11 was the widest aperture I was able to use without the lower right corner going oof.  Which happens to be right before diffraction becomes visible on both the f/1.8 and f/2.5.  Had I used the f/2.5 I almost certainly would have had to resort to f/16, at least, to save that corner and subsequently inviting diffraction.  The curvature on the borders, as you focused on, was not as extreme as the corners and I did not find these areas problematic in the f/2.5

I don't think the curvature plunge in the corners itself adds to portraiture, or anything really.  It just may force one to stop down further in some instances.  Overly nit-picky to most I am sure, and not at all the use people pick up the f/2.5 for.  I just happen to be striving for a very minimal and flexible set of primes.  I am interested to see any tests on this to deduce if it was the copy I tried or not.

For the future, I need to be more clear and give examples early on so these conversations can be spared plenty of fat.
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on December 28, 2016, 09:55:05
Tristin, forward field curvature should actually help getting the bottom right corner in focus, in your quoted example.

Whether forward field curvature helps achieving better (central) subject isolation is an interesting question. I mostly saw such statements in relation with wide angles, by the way, where such effects tend to be more apparent (see: Zeiss 28/2). In the present case, I am a bit skeptical as you are.

Akira, Roland, I think that the main problem with "bad bokeh" is double edging, itself related to outlining of OOF points. This is the primary issue. The secondary issue is, outlined OOF points will in addition make the polygon shape of the aperture all the more apparent. This is where the 105/2.5 AI fares better. But all versions tend to outline the OOF points, i.e. bokeh can be harsh, depending on the background.

I'll try a systematic comparison - shooting reflections on beads of various sizes at various distances lit by one or several point light sources should help exacerbate the problem (the dreaded jewellry product shots, so to say, but at more usual distances).
Title: Re: Comparing the bokeh of 3 Nikkor 105mm (and a 58mm Noct)
Post by: Airy on June 10, 2017, 08:26:17
The field curvature of the f/2.5 limits it's use as a landscape lense heavily and its poor handling of strong light sources in front of the lens (compared to the f/1.8 ) makes it a far worse lens for many uses.  I would not trust the f/2.5 to shoot live music, for example, as washed out images from stage lights would be the course for the night.

Finally I got an opportunity to shoot jazz musicians, and I had the 105/1.8 in the bag (together with the Voigt 58/1.4, unfortunately not the Noct Nikkor).

It seems that you were right about the qualities of the 105/1.8 with light sources in the field. I'll open a thread when the processing is finished.