[narual]

FYI, cyberjunkie, OP, and anyone else who owns or is considering a porst 55/1.2, yes, it's sort of milky/dreamy wide open... until you put a hood on it (one intended for 85mm lenses if you're on crop sensor).

And they're not kidding about the depth of field, and an 85mm/1.2 would be even narrower. Personally switching to a matte ee-s focusing screen helped but not enough - having focus peaking in live view makes it much easier.

Attached: all handheld in ambient light, with hood for sure on the foliage, the woman and I forget on the man but I think not; no hood for sure on the kid (that was the week I got the lens. I think that was actually like f/2 not 1.2 but you can still see the sort of dreamy/milky quality). Foliage shot is to show the narrow dof more obviously.

Attached Images

View Picture EXIF

File Date

 

View Picture EXIF

File Date

 

View Picture EXIF

File Date

 

View Picture EXIF

File Date

 

[cyberjunkie]

FYI, cyberjunkie, OP, and anyone else who owns or is considering a porst 55/1.2, yes, it's sort of milky/dreamy wide open... until you put a hood on it (one intended for 85mm lenses if you're on crop sensor).

And they're not kidding about the depth of field, and an 85mm/1.2 would be even narrower. Personally switching to a matte ee-s focusing screen helped but not enough - having focus peaking in live view makes it much easier.

Yes, a different focusing screen would help a lot, those sold with all Pentax DSLR cameras can be trusted down to f/1.7, if I remember correctly. I have a chinese split-image screen on my K10D that works fine with my fast fifties, and with a 1.4/85mm and 1.8/135mm.
Unfortunately the OP refers to full frame, and there are no such options for the K-1, so enlarged LiveView, with or without focus peaking, is the best way. The other is focus bracketing, shooting bursts while slightly adjusting the focusing ring.
The Porst doesn't have a very long focus throw, and my example should be re-greased (looser at one end and stiffer at the other), so I try to use the former option whenever possible.
You are right about the need for a working hood, it is highly beneficial with all the lenses with large front elements.
Unfortunately a properly sized lens hood can't compensate for the weak MC.
When I wrote that my vote was a 7 1/2 if used at night, but could have been a full point more in different conditions, I could have explained my point way better... but the post was already so long!
In practice, more than half of my pictures are shot at, or after, sunset. Many have strong artificial lights within the frame, or at an angle that couldn't be blocked by any lens hood.
The Pentax, and also the Revuenon, have better multicoating and the veiling flare is not so strong.
When I tried the Porst with different subjects, like flowers or portraits (avoiding contre jour), the results were completely different. I understand that for most people what really counts is daytime performance, and I aware that if the sun is the only light source, a proper lens hood and some common sense are all that is needed to overcome the limits of this optic.
When I wrote that the Porst is pure fun, I meant it. The "milkyness" (in photographic jargon: halation) that shows up wide open (or with varying intensity wider than f/4) is more evident than with other similar lenses I tried, and also the flare can be used in a creative way... which makes for a wide palette of different optical signatures, using the same lens.
Unfortunately the strong flare kills a good number of pictures shot in the kind of environment where a lens like this would be most useful (night events with strong artificial lights). But that's just me, others might have opposite requirements, and would use the lens in a completely different way.

I realized I overlooked one of the options chosen by the OP.
I don't have a Samyang fish-eye, my 8mm with circular full frame image is an old Peleng, which I'm sure doesn't match Samyang 8mm IQ and price/performance ratio.
Though I'd suggest a fish-eye made for full frame, like the Samyang 12mm. It seems to be great.
If there is no other UWA, I'd wait and make sure a fish-eye is really needed. I'd go first for a rectilinear UWA like the Samyang 14mm.
I own one, and I can say that it leaves my Pentax-A 15mm in the dust... unless I'm just considering build quality. Old lenses are always better in that regard, not just because of AF. Modern MF objectives, even the most expensive, are never better built than their counterparts made forty or fifty years ago.
Regarding Samyang's, all modern ones are more than fine, I also have a 1.4/35mm that is as great as the 14mm.
Let's face it, Samyang used to make abysmal optics, but now most of the lenses they make (but a few super cheap ones) are terrific value for their price.
From what I know, the 135mm f/2 is just terrific... even if price is of no concern, and it's directly compared with the best of the crop (Zeiss).
Not acknowledging the level recently reached by Samyang production is either due to a snobbish attitude, or to some kind of (rather silly) brand loyalty.
Let's be happy about the choice of great UWA primes offered by Samyang, Laowa and Irix.
If money is no bar, the new ultra super extra wide angle by Irix could find place in the same (big) bag containing one of the two super extra fast Mitakon teles
I firmly believe that the K-1 fully deserves some very good primes, to complement the few zooms released (or rebranded) by Pentax for its full frame camera.
Some say that it's more than enough for most uses, others have faith and wait for OEM primes.
Personally I see no problems in using Chinese or Korean manual focus lenses, and I've been amazed by how well the K-1 works with vintage glasses, even from the sixties/fifties
My interest for photography was getting colder, acquiring the K-1 and using it with some great vintage lenses made the difference, and gave new life and new opportunities to my photographic interests.

About the Porst 1.2/55mm, a few shots I posted on the Bokeh Club thread explain my point better than a thousand words

Cheers

Paolo

[cyberjunkie]

After the two very long posts, at least an example photo...
It's taken with the oldest super-fast lens i own.
The picture is nothing special, but it shows how important it is to nail the correct focusing, and which kind of result you can expect from a relatively cheap third party glass from the early seventies, used wide open.
The lens is a Raynox Polaris f/1.8 135mm released in 1973.
The picture is resized and compressed, the original is a little better. Though it shows well enough how thin is the depth of field at f/1.8.
There is some green-ish fringing, not too bad tough.



cheers

Paolo

[Wasp]

If it was my money, I would spend it on a 77mm Limited.

[cyberjunkie]

If it was my money, I would spend it on a 77mm Limited.

Yes, it's a beautiful little lens with a very nice rendition... and it's AF!
It's no magic bullet though.
It hunts in low light, more than slower (f/2.8) zooms; sometimes I give up and switch to MF.
It's too short to be used as a primary portrait lens, I found that the best focal is around 100/105mm.
It's a film era lens; I'm perfectly fine with a little CA (not invasive and only in certain conditions) and with resolution figures that don't match the best contemporary optical designs. It's not a macro lens after all, but some people might be unaware of the character of this lens and might find after the purchase that it's not a lens for obsessive pixel peepers
I like my 77mm Limited, but it's no Swiss Army knife.
Even acquired second hand, it's still expensive. For more or less the same price, speaking of fast lenses, I bought a Samyang 1.4/85mm first version, a Porst/Mitake 1.8/135mm and a Porst/Cosina 1.2/55mm.
If you want good sharpness wide open, better look elsewhere I mean, the Samyang is more than decent wide open, but the other two are severely lacking in that regard.
On the other hand, if the main goal is to experiment with blurred, creamy backgrounds, and the subject doesn't require very good sharpness, a cheap fast vintage lens could be more than enough for the job.

Sometimes I forget, taken by my love for vintage optics, that most lenses differ in minimal details, way beyond the capability to "see" of any casual viewer.
More than 90% of the merit goes to the photographer, to his/her control of light and composition, and of course to the simple fact of being in the right place at the right time.
Very few lenses make a really obvious difference. The donuts highlights of a mirror lens are an example, or the mix of halo and underlying sharpness of a soft-focus. In certain pictures a super fast lens turns the background into a mellow, unreal melange of colors and shapes; the same picture shot with a zoom of average speed shows the difference. If there are OOF highlights in the background an old Trioplan can show an overwhelming amount of bubble bokeh, an effect that the human eye will never see. Like the perspective of a fish-eye.
For sure there are other examples, but for the most part the differences between different optics can be spotted only by a very educated eye, the same way the difference between some esoteric HiFi and one that's just "good" can be perceived only by educated ears.
Only some lenses, actually very few, make a real difference. Most are just similar, unless we are after pixel peeping and not image making.
This is the reason that makes me stay with my Sigma 2.8/24-70mm, I know the new Pentax/Tamron is "better", but I mostly use primes and I decided that the new zoom is not "better" enough to deserve the money and the hassle.
It's a matter of priorities.

No lens would ever turn an average photographer into an artist.
Some would appeal, for a reason or the other, to the lover of vintage glasses (image making is kind of tangential, I know it very well cause I own plenty of old glasses).
Some, not so many, are "specialty lenses", that can be used as new tools to get new opportunities and experiment with a different aesthetic.
All the discussions about subtleties are... well, very pleasant I love them immensely, but when it comes to image making I think those subtleties should not be overestimated.

Cheers

Paolo

[bxf]

For portraits the best are: Leica, then Zeiss, then the rest.

This statement, even if technically correct (and I'd say that as a general statement that is arguable in itself), is very deceptive. I am sure I could find thousands of excellent images taken with one of "the rest", where nobody would think to say "nice, but it would have been better if it was taken with a Leica or Zeiss lens".

It is "unfair" to make someone feel that they must spend a small fortune to achieve excellent results.

[disconnekt]

Seeing as f/1.2 lenses command a pretty penny (at any focal length), depending on you're budget I'd say just go with the 85mm f/1.4 version & a 50mm f/1.4. Now if you got the money to throw out for the f/1.2 versions, go for it haha