NikonGear'23
Gear Talk => Lens Talk => Topic started by: Airy on September 10, 2016, 23:16:52
-
This is the first part. Three old Nikkors : 50/1.2 AI, 50/1.4 AIS, 50/1.8 AI. One newer design : 50/1.8 G. All shots handheld at 1/50s, so I took 3 to 5 pics of each lens and f stop (from lowest to 5.6) and selected the best one using the handy X/Y feature of Lightroom. Some de-noising when necessary, standard sharpening (slider: 25). The camera was a Df.
The tricky aspects are (1) the shiny front pipes; (2) the fact that the subject is generally darker than the surroundings. So glow and flare are potential issues.
First shot, f/1.2 by guess whom. The usual haze. Not really usable here. You'll find below the overall view and two crops.
-
Nest stop, f/1.4. The 50/1.4 AIS (bottom) is clearly better, but ill-adapted too. For reference, I generally found the 50/1.4 AIS to be better than the 50/1.2 at f/1.4. Stopping down from f/1.2 to f/1.4 does not fundamentally change the lens performance. For one thing, the 50/1.4 has the better contrast.
-
However if you look at the details, it is a tie. In the center, the lenses have a very different glow - the 50/1.2 (left) leaning towards purple while the 50/1.4 (right) leans towards blue. And while the 50/1.2 has a lower contrast, it is sharper, in the center and (even more so) in the lower left.
-
In any case, do not inspect the corners. They are equally mushy (ok, the 50/1.4 is not quite as bad), and there is also significant coma. By the way, the greater distortion of the 50/1.2 is visible here (greater slant of the columns)
-
Now at f/1.8, the old AI and the new G... Overall they look similar. The G looks warmer, but the weather outside was slightly cloudy, so I do not guarantee constant color temperature.
-
Now looking at the center, the conclusion seems clear : the new G is sharper. But both are free from nasty glow, and therefore more usable (arty effects aside) than the above ones at 1.4.
-
Looking into the lower left, same conclusion, but there is less striking a difference, maybe because the scene is dark. The G also sports higher contrast.
-
Looking into the upper right corner does not reveal any big difference. A bit more contrast with the G, maybe.
-
Near the center, this zone also shows the extra sharpness of the "G" version. But that's a small difference for a 40 years gap.
-
Now f/2, where the fab four can be compared. It is midnight, you got impatient but I got tired. I'll resume after a good sleep ;)
-
Thanks for the comparison so far.
-
Now all at f/2.0. In succession : 1.4 AIS, 1.8 AI, 1.2 AI and 1.8 G, whole field but downsampled, due to forum limitations. By the way, the filenames are explicit.
-
Now in pairs, starting with 1.4 and 1.8 AI. The 1.4AIS colors are warmer. Despite the uncertainty brought about by the changing weather conditions, I can state that, generally speaking, the 1.8AI (as well as 1.8AIS pancake) lean to the cool side.
Looking at the center, it is apparent that the 1.4 AIS is sharper. Also, the reflections on the front pipes are more color-neutral.
-
On the lower edge and top right corner, same observations. The corner sharpness is still wanting, but in any case the 50/1.4 is better. Coma is quite apparent in both cases.
-
Now the 50/1.4 AIS and the 50/1.2 AI. Their overall color balance is similar. To my surprize, the 50/1.4 is undisputably better in the center.
-
In the lower left, the difference is smaller: the 50/1.4 seems abit more contrasty, while the 50/1.2 seems to reveal more detail. That is probably because of the lesser vignetting of the 50/1.2, rather than a difference in sharpness (see the bright pipe mouths - not that good).
Along the lower right edge, the 50/1.4 is sharper and more contrasty (see for instance the suspended contraption, from a former gas-fed heating device). And in the bottom right corner, the 50/1.4 is much better, i.e. much less bad, but it does not matter a lot.
-
That leaves us with the 50/1.4 AIS vs. 50/1.8 G, at f/2.0. Overall rendition: the G is slightly cooler, but still "neutral" in my opinion. Of course it vignettes more.
-
Center : it's a tie. I would tend to think that the 1.4 is sharper, but the difference is not significant given the uncertainties of the whole process (focussing, camera shake...).
-
Off center, the results are clearly to the 50/1.8 G's advantage. There is more detail to be seen, and sharper edges.
-
In the top, the reverse is true. This is an out-of-focus area (less the case in the bottom, since the horizontal distance to the pipes etc. was greater than in the center). So I won't say that the difference in sharpness is the result of a difference in focussing plane; if any, it must be secondary. I have no explanation.
-
On the bottom edge, and taking into account the difference in illumination (effect of vignetting), the 50/1.4 also seems sharper. This is an area well in front of the focus plane.
I have seen some reports where increased sharpness off center would be attributed to mechanical vignetting (effectively reducing the aperture), but I do not see such an effect here. See also the corner picture: performance is about the same (except illumination); the G might have less coma (but the lower illumination certainly helps in this comparison).
-
Bottom line: in the present situation,
- the wide apertures 1.2, 1.4 are not really useful;
- the 1.8 aperture delivers usable pictures;
- at f/2.0, the old 1.4 AIS and the recent 1.8 G show similar performance, with a slight advantage to the AIS that seems to exhibit deeper DOF, versus the 1.8G that seems to handle point light sources a bit better. Color rendering is about neutral, with the G being slightly cooler;
- the 1.2 does not live up to its reputation of being the best (MF) Nikkor at 2.0, but beware of sample variation. Since my two 1.2 are identical, they are probably average, so maybe the 1.4 is stellar?
-
For reference, we have not yet reached ultimate sharpness. The center at f/4 looks like this (1.4 AIS and 1.8G). Note that the screen capture and jpg saving do some damage.
-
Airy, as mentioned in (2), thanks for sharing your effort.
One question: which coatings do Ais f1.2 and f1.4 lenses have, the newer SIC or the older NIC?
-
No idea. How can I make the difference? some kind of reflected color under certain lighting conditions?
-
I'm afraid I myself haven't tested side by side. If you happen to have the same lenses (say, Ais 50/1.4), the rendition of the pipes might be different in terms of the flare...
The difference between NIC and SIC in appearance is fairly obvious. NIC looks differently in beautifully saturated colors according to the elements. SIC shows generally dull green color, which suggests the lower reflections in wider range.
-
A wonderful organ. 3 sets of pipes echoeing the form. Wonderful.