[JonPB]

My best guess:
f/2.8:
1 - Zeiss
2 - 16-50
3 - 55

f/1.4:
1 - 55
2 - Zeiss

I might say that because I like #3 and #1 the most, respectively, and I wouldn't mind being convinced to get the 55.

[SteveM]

My guess


F2.8 Series
Image #1 - DA*16-50mm
Image #2 - DA*55mm
Image #3 - Zeiss

1.4 Series
Image #1 - DA*55mm
Image #2 - Zeiss

[k100d]

the Zeiss 50 Planar usually has very rough bokeh
which is strange because most fast 50's are of a planar design including the Pentax

[Minawee]

the Zeiss 50 Planar usually has very rough bokeh...

I would have to disagree with this point. The Zeiss Planar T* 50mm has a bokeh that is often compared to that of the Nokton 58mm - a lens very well-known for it's "dreamy/buttery" bokeh. The Zeiss doesn't exhibit the Nokton's level of "dreaminess" in it's bokeh, but is still quite "buttery" and smooth with enough character to distinguish itself. I was initially drawn to this type of bokeh, but felt the Nokton was a little too overkill in this regard, whereas the Zeiss struck a nice balance between Nokton-esque bokeh and just great standard bokeh. This is the reason I chose to go with the Zeiss over the Nokton...

There are many comparison threads in this and other forums on the WWW between these two lenses, and I think I read every single one of them

Regardless of planar-type/based designs of Pentax (and other) lenses, I still think there are notable differences between them - I just wouldn't cosinder "very rough bokeh" to be one of them

-Paul

[k100d]

i personally wouldn't classify the Zeiss samples i've seen as "creamy" but it's all subjective anyways; as long as you're happy w/ the purchase that's all that matters

[georgweb]

As regards to the Planar designation, this is a very broad term that's been used for a variety of optics. See for an excellent intro here.
The original symmetrical 6-in-4 double Gauss has evolved to a rather different optics in the 1.4/50 Zeiss design from 1973, which has remained til today:

Also, even if a lens design is very similar it will not necessarily have the same attributes - slight mods in the lens scheme as well as different glass and coatings used will make for a very different bokeh.

Regarding the Bokeh question, I would agree it is all subjective - I for one would see the Zeiss Planar 1.4/50 vs. the Voigt 58/1.4 on the opposite ends though. I'd invite y'all posting pictures in the fine https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/31244-bokeh-ma...ggestions.html thread and also this one "Admirable" blur samples - FM Forums

Here's one last subjective Bokeh ranking, were said Planar scores quite low, http://free.art.pl/fotografie/johnston/LensBokehRatings.pdf respectively the intro to it: Bokeh Ratings and Lens Awards

Best, Georg (the other)

[cwood]

we need an answer here!!

[Minawee]

we need an answer here!!

Sorry...computer issues these past few days...

Anyhow, the answers are:

F2.8 Series:
Image #1 - Pentax DA* 16-50mm SDM
Image #2 - Zeiss Planar T* 50mm
Image #3 - Pentax DA* 55mm SDM

F1.4 Series:
Image #1 - Zeiss Planar T* 50mm
Image #2 - Pentax DA* 55mm SDM

Anyone surprised? I know there must be some thoughts out there...let's here 'em.

-Paul

[Minawee]

Here's one last subjective Bokeh ranking, were said Planar scores quite low, URL]http://free.art.pl/fotografie/johnston/LensBokehRatings.pdf[/URL] respectively the intro to it: Bokeh Ratings and Lens Awards

Best, Georg (the other)

It should be noted that the Zeiss Planar 50mm f1.4 used in that review is the older version and not their newest T* version released in (IIRC) 2007.

-Paul

[nostatic]

I think they all look good, and the 16-50* hangs in very well for a zoom.

Funny, but I could have sworn that #3 from 2.8 and #1 from 1.4 were the same based on the color response in the flower in the center. But the bokeh does show a little more relation between #2 in 2.8 and #1 in 1.4.

[georgweb]

Minawee/Paul,
I just looked at the 3x2.8 series and had the zoom as #1 but mixed #2 and #3 up.
Thanks a lot for putting up the test.

Paul said:
"It should be noted that the Zeiss Planar 50mm f1.4 used in that review is the older version and not their newest T* version released in (IIRC) 2007."

The red T* coating did change over time cause Zeiss/Cosina tried out different things for color rendition (sent an e-mail a while ago and that was the answer re. Contax AE to MM differences). The older Contax AE versions have a ninja star aperture til ca. f/4 and the latest versions have nearly round blades at all apertures AFAIK (maybe you could verify that Paul). All this contributes to very visible differences of bokeh say at a near distance @f/2.8.
AFAIK the lens scheme is still the exact same since 1973.
Best, Georg (the other)