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09-19-2018, 07:42 AM   #31
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If anyone wants to compare optical formulas for Pentax lenses, this page rules.

09-23-2018, 08:29 AM - 2 Likes   #32
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QuoteOriginally posted by jatrax Quote
On the other hand if you really need f/1.8 then this is pretty much the only game in town.
Not the only one.
It's the only Pentax and maybe the best (optically), excluding adapted lenses, though there are a number of other options, even discarding leitaxed/adapted objectives.
I have a couple of them myself.
The best is the Soligor (Tokina) C/D P f/2 135mm, which is not exactly as fast, but has a nice bokeh, good overall rendering, and a build quality not far from the outstanding mechanics of Pentax-A Star lenses.
It's a very good portrait lens, and maybe it was also made in PK mount. I have the M42 version cause I found it at an affordable price. I don't think a PKA version was ever made.
The second is the Porst (Makinon) 1.8/135mm in PK mount. It's a decent performer, it's not rare, and it's rather easy to find it on Ebay. It's also the cheapest of the three.
The last is a Raynox Polaris 1.8/135mm in M42 screwmount. It's the oldest, it's not very sharp wide open, but I like the rendering. It has proven to be better than I expected.

None of them is very expensive, and all of them serve their purpose: thin DOF and blurred backgrounds.

Here is a picture with the optical designs of all the vintage f/1.8 135mm's that can be used on a Pentax DSLR camera.
The Zeiss could be adaptable using a Leitax mount. I don't remember which Zeiss are adaptable, and I have no idea if a lens similar to the one in the picture has been successfully adapted. Others on this forum know much better
Credit goes to whoever posted this interesting picture in the first place. Sorry, I have no track of the original URL/author.


This post is old, though after seeing it has been revived, I decided to share the little info I know, showing a few possible alternatives to either the old A* and the Sammy.
I believe the monumental A* has something more than the Samyang, and of course it's not sharpness wide open.
What the Pentax has for sure is a great build and the pleasure of handling (and shooting with) such a smooth, refined, beautiful objective.
I didn't buy it when i had the funds and the price was much lower, but I know very well how these lenses are, cause I have other three A Star's.
Leaving aside the collector's value and considerations about the build, a fair way to compare the Pentax to the Samyang would be to test the way they handle out of focus.
The Samyang wins hands down in sharpness, it's one of the most amazing (fast) 135mm's ever.
I also expect a better handling of both LaCA and LoCA.
What I don't know, and would like to see, is the performance of the Pentax on different focus planes of the image.
To do that, pictures have to be shot with bokeh in mind. Which generally means to leave the in-focus subject on one side, leave some blurred foreground if at all possible, and have different planes of progressive defocusing. The background should be distant, possibly with strong highlights.
I'm sure there are a number of photos of this kind shot with the Sammy. I remember I checked Flickr for examples of its bokeh.
Pictures shot with the A* are scarce, and I think I've seen none of them properly showing how it handles OOF rendering.
Until I see how it fares under this point of view I reserve my judgement.
From my personal experience I have understood that some over-hyped optics might cost a bit too much, but the rendition is definitely special... and not because they are sharp!
Some Meyer lenses, like the Trioplans and the Primoplan, are probably a little overpriced, though if you compare them with an humble Pentax-M 2/50mm and say that they should be cheaper because they are not as sharp.... well, I guess would be pointless to try to argue that photography is not mathematics

Last edited by cyberjunkie; 09-23-2018 at 09:28 AM.
09-28-2018, 06:07 AM - 1 Like   #33
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QuoteOriginally posted by rozand Quote
just busy experimenting. all handheld, catch-in-focus

photographs did not upload initially, retrying

also several here: Vanishing into green by Roger van Zandvoort - Photo 274817197 / 500px
Beautiful!!!!
09-28-2018, 07:02 AM - 1 Like   #34
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QuoteOriginally posted by Kerrowdown Quote
Absolutely.
Inasmuch as I own one, I gotta got with Kerrowdown.

In fact, I'll add, "At least!"

10-14-2018, 06:12 AM   #35
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QuoteOriginally posted by SunnyG. Quote
Is this lens really worth 2000$+ ? All the lenses listed on eBay are going for this. Collectors item? Or is it miles ahead of the Pentax FA 135mm 2.8 and Pentax F 135mm f2.8 in performance? Or is it both? Damn this lens got my interest.
i am comparing this lens with the fa* 200mm macro. Set-up is the 135mm 1.8 with the xpro achromatic close-up lens f500. Although its use this way is way more limited than using the 200mm, i need to say the outcome is great. Once you get focussing right, the lens produces even more sharp results than the 200mm macro.

https://www.pentaxforums.com/gallery/photo-little-lady-damselfly-56526/

135mm top url
200mm url below

https://500px.com/photo/276968991/small-nightshade-on-green-by-roger-van-zandvoort

Last edited by rozand; 10-14-2018 at 06:36 AM.
10-14-2018, 07:13 AM   #36
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QuoteOriginally posted by beholder3 Quote
I even venture to say that my approach is the one billions of people on this planet use every day prior to making buying decisions.
How do you compensate for the different skills of the various photographers?
I bought my DA*55 after comparing it's images with the DFA 50, after someone posted a direct comparison, same image. The differences were apparent, and I was able to make an informed decision. I don't see how that fact that most of humanity doesn't make informed decisions helps your case.

Just because billions of people make poor decisions, does that mean you want to join them? Sounds like a good plan if your goal is to take to take average photos that look like everyone else's.
10-14-2018, 08:02 AM   #37
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QuoteOriginally posted by normhead Quote
How do you compensate for the different skills of the various photographers?
I bought my DA*55 after comparing it's images with the DFA 50, after someone posted a direct comparison, same image. The differences were apparent, and I was able to make an informed decision.
You are citing the wrong person. I said that I base my judgement on the available images like many people do.
You say, you based your decision on posted images as well.

The user Kerrowdown argued against your case and said that your decision was not "informed" because you did not own and handle the lens before you bought it, you "just" watched images.

Anyhow, all the images in this thread are of a quality supporting my position that the A*135mm definitely is not a "great" lens. By modern standards it seems it is not even average.
10-14-2018, 03:16 PM   #38
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QuoteOriginally posted by SunnyG. Quote
You cannot send messages to the sellers unless you buy the product
Are you talking about the Japanese sellers on ebay? I send messages to them all the time. I've never bought a lens at their advertised "Buy it now" price. I always offer about 75% and they usually counter with something or they tell me to buzz off. If the former, we negotiate a little, and if the latter, I go on with my life. If the former leads to success, then I usually end up paying 80-85% of the asking price.

---------- Post added 14th Oct 2018 at 05:28 PM ----------

QuoteOriginally posted by beholder3 Quote
The highly esteemed user Kerrowdown ....
you forgot a couple of words, so I inserted them for you


Last edited by jcdoss; 10-14-2018 at 03:29 PM.
10-14-2018, 07:11 PM   #39
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QuoteOriginally posted by normhead Quote
How do you compensate for the different skills of the various photographers?
I bought my DA*55 after comparing it's images with the DFA 50, after someone posted a direct comparison, same image. The differences were apparent, and I was able to make an informed decision. I don't see how that fact that most of humanity doesn't make informed decisions helps your case.

Just because billions of people make poor decisions, does that mean you want to join them? Sounds like a good plan if your goal is to take to take average photos that look like everyone else's.
I also don't see how dropping 2000 dollars on a lens to see whether or not something is actually good is exactly reasonable either.

If this lens is really that good why don't any of the owners do side by side shots with other more modern 135s? Or hell, any 135.



---------- Post added 10-14-18 at 10:14 PM ----------

QuoteOriginally posted by jcdoss Quote
you forgot a couple of words, so I inserted them for you
How about we don't put people on pedestals and have a normal discussion.
10-14-2018, 11:35 PM   #40
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QuoteOriginally posted by ZombieArmy Quote
I also don't see how dropping 2000 dollars on a lens to see whether or not something is actually good is exactly reasonable either.

If this lens is really that good why don't any of the owners do side by side shots with other more modern 135s? Or hell, any 135.
Or provide sample raw files of meaningful subjects at infinity distance shot wide open? Or at least 36 MPx full res images? Or a set of 100 % crops?


All we get from a lens that is claimed to be very good is web samples which can't be distinguished from smartphone shots or any other lens.

Why are from the very few samples so many stopped down (a lot)? A f1.8 lens has to deliver wide open.
10-15-2018, 01:07 AM - 1 Like   #41
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QuoteOriginally posted by beholder3 Quote
Or provide sample raw files of meaningful subjects at infinity distance shot wide open? Or at least 36 MPx full res images? Or a set of 100 % crops?
I doubt it would be really useful.
In all sincerity, I'd love to own (or at least test for a few days) such beautiful lens, but I wouldn't expect a much better sharpness at, say f/2.8, than the AF version of the same focal. And of course it would be trashed by the Samyang (in sharpness and fringing).
Albeit not as beautifully made, it matches the best of the crop (Zeiss).
Very few times what you expect from optical design is not matched by real life performance.
At that time, using no ED glasses, Pentax designers did the best they could.
I remember when it was released, it was a very good lens, but not as outstanding as the 85mm.
Let's not forget that in film times super fast lenses were designed to allow for easier focusing in extremely low light. Shooting wide open was last resort, to avoid motion blur. The best photographers of sports/concerts/etc made an extensive use of panning. In digital time it can be used for creative purposes, it's not a necessity anymore.

Having said all that, sharpness is not a dogma, and pixel peeping is a captivating pastime, but not a goal. The way we like or dislike the rendering of a picture is all that matters, in the end.
I'd like to see pictures shot with the A*, wide open or closed one click, showing in high res the way this lens handles out of focus. From distant highlights to almost in focus.
Shooting at infinity would inevitably highlight the faults and take out of the equation the possible strong points.
The only important optical design optimized for infinity I'm aware of is the Leitz Canada Apo Telyt 180mm. Because of a specific US Navvy request.

As much as I like to see myths debunked, I like old lenses So I appreciate when they are given a fair chance to show what they are capable of. Shooting optical targets or concentrating on infinity performance is a kind of mistreatment such old ladies should not be exposed to

Previous posts already highlighted the substantial lack of pictures shot wide open with the A* 1.8/135mm.
The total number of posted pics is quite low, and very few are actually shot in a way that could evidence the possible strengths of this lens.
I am very curious about the real performance of this beautiful example of opto-mechanical design.
Pictures intentionally shot "for bokeh" would help to understand the real value of a lens of this kind.
I love photographic lenses since long time, I developed my own tastes and had the chance to use a lot of different optics, but I am still very far from the level of understanding and experience of real connoisseurs. It's like with Hi-Fi, the more you get into it, the more you appreciate subtle differences... that become not so subtle once you learn what to look for.
I have two friends who repaired and tested a huge number of optics, including the very best. One still adjusts the focusing of rangefinder Leica lenses to minimal tolerances.
Sometime I realise the competence gap, it's like when a Hi-Fi enthusiast tells me why he likes the analog (vinyl) more than the digital (CD). It's way beyond my reach
Though I still trust my eyes more than anything else and try my best to have unbiased opinions.
IMHO the best way to judge the performance of a lens like the A* is to carefully check images that could evidence its potential.
Something like this. Main subject off center, various planes of progressive defocusing. It would have been better to have the background further away, and with some strong highlights.

Leitz Canada Summicron 2/90mm @f/2 on K-1 full frame

Last edited by cyberjunkie; 10-16-2018 at 07:53 AM. Reason: added picture as example
10-15-2018, 01:15 AM   #42
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QuoteOriginally posted by cyberjunkie Quote
I'd like to see pictures shot with the A*, wide open or closed one click, showing in high res the way this lens handles out of focus. From distant highlights to almost in focus.
Shooting at infinity would inevitably highlight the faults and take out of the equation the possible strong points.
Since providing full res images is so simple I would agree to your points but add that both scenarios need to be provided so any watcher can make up their mind. If it is a good lens the owners will have hundreds of images of all kinds with that lens. Sharing 5 different ones of them is a matter of minutes.
10-15-2018, 05:39 AM - 1 Like   #43
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Tulip mania - Wikipedia

The point? You are never going to be convinced. Others will never be unconvinced. What would you spend your $2000 on? Computers? Hats? Baked Beans? Someone will be able to come up with some condescending reasons why that would be a waste of money. Why not just decide for yourself that the A*135 is a waste of *your* money and get on with your life without ridiculing those who might disagree?
10-15-2018, 06:00 AM   #44
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Forums are there for exchanging opinions, so you have to live with other opinions or just stay away.

Much more so when nobody seems able to show any photographic evidence that this lens is optically better than any other old mediocre manual focus lens.



No evidence of it being worth more than the discussed 276 EUR in mint condition for anyone else than collectors.
10-15-2018, 06:08 AM - 6 Likes   #45
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QuoteOriginally posted by beholder3 Quote
Forums are there for exchanging opinions, so you have to live with other opinions or just stay away.

Much more so when nobody seems able to show any photographic evidence that this lens is optically better than any other old mediocre manual focus lens.



No evidence of it being worth more than the discussed 276 EUR in mint condition for anyone else than collectors.
Ya, ya, we get it, you know more than all those people willing to pay the big bucks for the lens.

QuoteQuote:
Argument from ignorance (from Latin: argumentum ad ignorantiam), also known as appeal to ignorance (in which ignorance represents "a lack of contrary evidence") is a fallacy in informal logic. It asserts that a proposition is true because it has not yet been proven false or a proposition is false because it has not yet been proven true. This represents a type of false dichotomy in that it excludes a third option, which is that there may have been an insufficient investigation, and therefore there is insufficient information to prove the proposition be either true or false. Nor does it allow the admission that the choices may in fact not be two (true or false), but may be as many as four,
Argument from ignorance - Wikipedia

I have absolutely no compulsion to make judgements as to the value of this lens, either way. It's an open question waiting for a definitive answer.

There are very few lenses if any, that have direct comparisons images. There are only a few places you can see results for different cameras, I know of none that compare different lenses. Asking people to find Imaging Resources type camera comparison images for lenses is impossible. Meaning working solely on images, you'll be working from ignorance, most of the time.

Personally I lucked out. I dropped my FA 50. Need a new fast 50, the DA*55 was available, the DFA 50 1.4 had just come out. I was able to see direct comparison images. The DFA 50 looked better in ways that were not significant to my shooting. But I could also see why someone else might pay the extra $700 for the DFA. That is an informed decision.

I lucked out, usually these kinds of decisions are a hope and prayer.

The thing with lens comparisons is, if you have two 135s and you know which you like, why would you take the time to do a comparison. What's in it for the tester. I can tell you. A lot of people complaining about your methodology. A lot of people who want to argue with your results. Nothing but grief.

So why would you do that with all these internet experts that know better out there?

Although I have to say, doing the tests teaches you way more than can be conveyed in a test write up. To the point I'd say, you shouldn't be commenting until you've done a few tests yourself. Many of the attributes that make a lens desirable are really not all that quantifiable.

I don't pay much attention to anyone who hasn't put a bunch of lenses down on their table and tried them all one after the other to produce comparison images, like I do for various focal lengths. Doing that, you know way more about the lenses, how nice they are to use, how easy it is to achieve focus etc. images are just part of the package.

Last edited by normhead; 10-15-2018 at 04:28 PM.
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