Originally posted by Sliver-Surfer Thanks for asking. Yes to all. As with you all I can offer is my opinion. I like the A 1.2/50mm pentax because I prefer the Contrast, Bokeh and Sharpness.
Well, let's not exaggerate.
I own three different f/1.2 fifties, and the Pentax is not the best.
If you value sharpness, especially outside the center of the frame - I don't - you got to stop down a few clicks.
Bokeh is nice, but it's ruined by an horrendous amount of Bokeh fringing (LoCA).
Contrast is quite good for an f/1.2 lens (thanks to SMC coating), but not at the top.
All in all, a nice lens that shines in its own specific way, not a great all-rounder like the Zeiss.
I have no first hand experience with modern Zeiss lenses, only with old ones like those for Rollei and Contax (not the f/1.4 unfortunately).
Being a collector, my judgement, and my purchase strategies, are conditioned by my love for vintage optics.
Though I can make and educated guess, based on Flickr pictures and MTF charts. I tend to agree with @Fenwoodian: the new design should beat the Classic version, and economically it makes more sense to leitax a ZF version or even the Contax one.
Having said all that, I just missed a Sigma EX DG HSM sold from japan, like new, for $292 shipped. It should match the Zeiss at the center, and it's AF.
As I already wrote on another thread, I got interested in the Samyang, which is a kind of poor man's Zeiss Classic. If it's half as good as the 135mm it would be a very interesting alternative option. Maybe not as distant from the Zeiss as some people think... and here I stop, cause I might come out with some blasphemy
After I extensively tried the Samyangs I have, in all honesty I can say I'm seriously impressed. More by the 35mm and 24mm, and a bit less by the 14mm and 85mm, but all of them are fine lenses. Not with a great build, but not plasticky either, and the former two show a brightness of the image that is normally found in optics of more noble lineage.
Regarding the LoCA shown by the Pentax 1.2/50mm, I want to be clear.
I don't mean that it can't be found in other lenses, even blue blood ones. Actually my Leitz Elmarit 2.8/135mm has plenty.
It is the kind of bokeh fringing. The Elmarit has much softer rings around OOF highlights, while the Pentax has thick well defined blue rings that can be used creatively but most of the times are plain annoying.
---------- Post added 10-10-18 at 10:46 AM ----------
Originally posted by grahame 8-element ST is known for its very smooth bokeh and beautiful transition, but not for sharpness and resolution wide open -- few lenses at that time are design for wide open sharpness.
Did you see the MTF chart on photodo.com?
I have been impressed by the bokeh and the round, beautiful rendition of the 8-elements version of the Super Tak.
These are not qualities that are in any way reflected in an MTF chart, but still are an important (to my taste, prevalent) character that we consider when we express a judgement about a lens.
Just sticking to the MTF chart, and leaving out any other consideration, what left me seriously impressed is the level of performance stopped down.
Let's not forget that it's a single coated lens, and that contrast, together with resolution, gives the perceived sharpness (which is essentially what MTF measures). The old tests were done with targets, which meant that a lens could score high (i.e. resolve a high number of lines/mm), without giving a perception of good sharpness, cause the contrast was low.
MTF charts give a more realistic measurement, and in this case the chart highlights the performance of the lens stopped down.
Wide open it's rather good at the center, and quite bad at the borders, but once it's stopped down a few clicks it gets better than the FA 1.4/50mm!
Consistently better from medium to minimal apertures. It seems that this design suffers diffraction way less than a more modern one.
Really impressive.