First images SMC Pentax 85mm f/1.8

caspert79 · Joined: 31 Oct 2010 Posts: 3129 Location: The Netherlands

First images of my latest acquisition. Click for full size.

SMCPentax8518459 by devoscasper, on Flickr

SMCPentax8518464 by devoscasper, on Flickr

SMCPentax8518457 by devoscasper, on Flickr

SMCPentax8518450 by devoscasper, on Flickr

SMCPentax8518449 by devoscasper, on Flickr

55 · Expire: 2022-06-15

Excellent results, caspert! Like 1 small

It's delightful to see a portrait lens put to good use.

As far as I know, the PK mount SMC 85 is a scarce lens which usually fetches high prices. Congrats on a good find.

caspert79 · Joined: 31 Oct 2010 Posts: 3129 Location: The Netherlands

LittleAlex · Posted: Sat Sep 02, 2023 5:57 pm Post subject:

visualopsins · Expire: 2025-04-11

alex_d · Joined: 19 Jan 2019 Posts: 377

nice,

is that a sonar ?

LittleAlex · Posted: Sat Sep 02, 2023 6:13 pm Post subject:

My long experience in that field shows me, that for the face-shoulder portraits with 85-100mm lenses the best f-stop always will be 4.0 So, all the face then is in focus, and still the back plane is moody enough to give the good impression.

caspert79 · Joined: 31 Oct 2010 Posts: 3129 Location: The Netherlands

stevemark · Joined: 29 Apr 2011 Posts: 3925 Location: Switzerland

LittleAlex · Posted: Sat Sep 02, 2023 7:10 pm Post subject:

stevemark · Joined: 29 Apr 2011 Posts: 3925 Location: Switzerland

LittleAlex · Posted: Sat Sep 02, 2023 7:30 pm Post subject:

[quote="stevemark"]

caspert79 · Joined: 31 Oct 2010 Posts: 3129 Location: The Netherlands

LittleAlex · Posted: Sat Sep 02, 2023 7:33 pm Post subject:

caspert79 · Joined: 31 Oct 2010 Posts: 3129 Location: The Netherlands

Dejan · Joined: 05 Jan 2021 Posts: 147 Location: Belgrade, Serbia

Yeah, if DOF is too shallow or too deep depends on what you want to achieve and focus on, if the portrait is meant to be environmental or fully focused on the subject. As long the selection is intentional and not forced (by lack of light, lens being too slow, background being wrong, or a mistake...) that's fine and purely an artistic choice. I can't see how one can be better or worse as a general rule, as there shouldn't be one.
In any case, beautiful results with this Pentax, very nice rendering with typical SMC colour rendering it. I was going to hunt down this lens before, but I couldn't find a good offer before the prices went up. Since I'm not much of a portrait shooter, I'll just admire the lens from afar. For some reason, I did like Canon FD 85mm the most, but its price also jumped of course (I wish it was still cca 180-200 eur like it used to be few years ago).

caspert79 · Joined: 31 Oct 2010 Posts: 3129 Location: The Netherlands

stevemark · Joined: 29 Apr 2011 Posts: 3925 Location: Switzerland

visualopsins · Expire: 2025-04-11

This SMC Pentax K-mount lens has the same optics as the Super-Multi-Coated Takumar M42, yes?

caspert79 · Joined: 31 Oct 2010 Posts: 3129 Location: The Netherlands

alex_d · Joined: 19 Jan 2019 Posts: 377

stevemark · Joined: 29 Apr 2011 Posts: 3925 Location: Switzerland

alex_d · Joined: 19 Jan 2019 Posts: 377

@stevemark

sure, that 'small' difference.

like a normal burger and a burger with 1 leave of green salat inside .. covered in sauce or .. whatever ppl put inside.

visualopsins · Expire: 2025-04-11

stevemark · Joined: 29 Apr 2011 Posts: 3925 Location: Switzerland

Allow me to add a few historical facts.

As you know the Ernostar design was the basis for the later Sonnar. The Ernostar was based on the Unar, which basically was a triplet with two positive front lenses (instead of only one):

Back in the 1920s when Ludwig Bertele modified the Unar into his early Ernostars, coating hadn't been invented yet. Lenses with six air/glass surfaces (such as the triplet) had less internal reflections than the Unar/Ernostar with its eight surfaces. Those eight surfaces were just OK (and six surfaces were better of course), but more air/glass surfaces would not be feasible.

Just around this time - late 1920s - the silent movies were replaced by talkies. Silent movies - if shot indoors - had made use of the noisy, but very bright arc lamps. Their noise was completely unbearable for talkies, and they had to be replaced by the much weaker filament lamps. As a consequence there was a sudden and urgent demand for fast cinema lenses. f2 ... f1.5 ... you name it. Money was not an issue, but the lenses had to be fast: pronto, subito.

Bertele, then working at Ernemann, as well as MertÃ© at Zeiss came up with different solutions. MertÃ© was transforming the original slow and symmetric Planar into a fast, asymmetric f2 Biotar (which had four air/glass surfaces).

Bertele however had a brilliant idea: He would take the basic Unar/Ernostar design, and fill the air space between second and third lens with low refractive / low dispersive glass. This would result in two advantages:
1) only six air/glass surfaces (instead of eight with the Ernostar & Planar), and
2) reduced lateral CAs due to the use of LD glass.

The rather limited angle of field of the original Unar was enhanced by inserting a "hidden surface" into the rearmost lens. The Sonnar was born:

You can find a more detailed historical description in my 2011 article about the Sonnar, publshed in the Sony Fotospiegel. Its German language, but the corresponding lens schemes are self explanatory:
http://artaphot.ch/images/Technik/Zeiss/Sonnar/FS142_History_ZeissSonnar_150dpi.pdf

Bertele, by the way, had become famous due to his Ernostar and Sonnar designs. He wasn't happy at Zeiss, though, and even before the end of the war he left Zeiss (around 1944 as far as I know). Pretty soon he re-surfaced just a few 100 meters from the German-Swiss border, but this time in Switzerland. The (for insider) famous Wild Heerbrugg would be his new home - until his death in 1985. Actually I grew up in a village next to his place of residence, but sadly we never met. His two sons, now in their 80s as well, are still alive though, and you'll find their entries in the official Swiss phone directory ...

Enough for today.

S