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12-15-2013, 04:46 AM   #391
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To play devil's advocate again: designing lenses for people is pretty dangerous. Tastes vary equally as much as there are people. Some like the Pentax rendering with vignetting, soft borders and colours, others will dislike it. Moreover, it's completely subjective. Whilst designing lenses for test chart is measurable, objective. No discussion in the latter.

12-15-2013, 06:20 AM   #392
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QuoteOriginally posted by normhead Quote
Hirakawa's motives are clearly defined in his technical notes.
I meant to ask northcoastgreg how he knows about what Hirakawa had in mind specifically for the DA* 55/1.4.

There is no dispute about the 43/1.9 and the 77/1.8 having been designed with aesthetics in mind. Extrapolating the same design goals to the DA* 55/1.4 is just speculation.
Given that the DA* 55/1.4 measures really well, but has far less appealing bokeh than say the FA 77/1.8, I'm wondering whether Hirakawa tried to stick to the philosophy he applied to his earlier creations.

QuoteOriginally posted by normhead Quote
To me the 18-135 is the 31ltd of zooms…
To each their own.

That lens is just too poor a performer at the long end to get become even a candidate, AFAIC.

The best contender for that title I know of would have to be the Sigma 18-35/1.8.

QuoteOriginally posted by normhead Quote
Uncompromising when possible, sharp centre and soft edges when trade offs are required by design constrictions, as to tends not to be the case with manufactures like Sigma, who seem to go for a less centre sharp, but more consistent edge to edge philosophy.
Sigma produces so many lenses with different design goals that it is impossible to make such generalisations.

The Sigma 30/1.4, for instance, has excellent centre sharpness but gets quite a bit weaker towards the edges. It is often criticised for being so "inconsistent" and it is by far not the only Sigma lens with that characteristic.
12-15-2013, 06:34 AM - 2 Likes   #393
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CLass A, did you really just say.

QuoteQuote:
That lens is just too poor a performer at the long end to get become even a candidate, AFAIC.

The best contender for that title I know of would have to be the Sigma 18-35/1.8.
?

QuoteQuote:
OK, so how good is a performer is the 18-35 at the long end? Ooops, it doesn't even have a long end. Focus man, focus.
To play devil's advocate again: designing lenses for people is pretty dangerous. Tastes vary equally as much as there are people. Some like the Pentax rendering with vignetting, soft borders and colours, others will dislike it. Moreover, it's completely subjective. Whilst designing lenses for test chart is measurable, objective. No discussion in the latter.
As per usual, you describe the perceived Pentax attributse by their negative qualities, don't bother to mention that others produce lenses with similar issues, some without even bothering to achieve the Pentax centre sharpness. You should really change your nick to something like "Pentax_detractor." Truth in advertising and all that. I've never encountered before an internet persona before that continuously posts on the negative side of others peoples equipment with so little appreciation for or even acknowledging the positive.

What a load of crap. If designing the way Pentax used to design is "completely subjective", how did they know when they had it right.? See, you've left me a choice here. I can decide you know what you're talking about and Pentax engineers were all idiots. Or I can decide the opposite. Guess which way I'm leaning? After all, I like what they did, you, have you ever done anything but trash Pentax equipment? The fact that then Pentax design parameters and criteria are unknown, and being trade secrets, are likely to ever be known, does not mean they didn't exist, despite your assertion that they were "totally subjective". I don't know how one person can be so continually wrong and so many times, in one post with so few words.

Last edited by normhead; 12-15-2013 at 06:57 AM.
12-15-2013, 09:54 AM   #394
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Are you familiar with the term 'false dichotomy'? 'Strawman'?

12-15-2013, 11:03 AM   #395
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More than familiar, read back in the thread, you'll see several instances where a specific person said I said something I didn't say, and then proceeded to refute it. But of course you know that, you're following the thread, not cherry picking and then attacking a specific person.

Have you familiar with the term "piling on" ?

That's when one person engages another in conversation, and another jumps in to support one or the other without adding anything to the thread, apart from adding to the attack. it can also be construed as bullying…. not that I mind, but you should understand the concept.
12-15-2013, 01:44 PM   #396
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QuoteOriginally posted by normhead Quote
More than familiar
Finally, we agree!
12-15-2013, 01:56 PM   #397
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It's not the first time...
12-15-2013, 07:00 PM   #398
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QuoteOriginally posted by Class A Quote
Given that the DA* 55/1.4 measures really well, but has far less appealing bokeh than say the FA 77/1.8, I'm wondering whether Hirakawa tried to stick to the philosophy he applied to his earlier creations.
The problem with this theory is the DA* 55 is not the only Hirakawa lens that has generated complaints about bokeh, nor is it the only Hirakawa lens that does well on tests (at least on resolution tests). The FA* 85, the FA 77, the DA 40 and especially the FA 43 all have reputations for being super sharp. And keep in mind as well: the DA* 55 was designed before Hoya took over. Nor would I judge the philosophy that went into a lens on the bokeh alone.

12-16-2013, 01:35 AM   #399
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QuoteOriginally posted by normhead Quote
What a load of crap. If designing the way Pentax used to design is "completely subjective", how did they know when they had it right.?
You've answered your own question. Obviously, Pentax didn't know when they had it right. Otherwise they would have continued with the right formulas, instead of laying off engineers who got it right. And discontinuing lens designs that were right. Pentax gets it right all the time, and when they do they switch to take another course.


QuoteOriginally posted by normhead Quote
See, you've left me a choice here. I can decide you know what you're talking about and Pentax engineers were all idiots.
The engineers certainly weren't idiots, the people that layed them off certainly were. I would have thought you'd agree with that. But that requires you to pick up on it first of course.


QuoteOriginally posted by normhead Quote
Or I can decide the opposite. Guess which way I'm leaning? After all, I like what they did, you, have you ever done anything but trash Pentax equipment?
Yeah lots, but that's not gonna keep you from ignoring it, is it?
12-16-2013, 01:50 PM   #400
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QuoteOriginally posted by northcoastgreg Quote
The problem with this theory is the DA* 55 is not the only Hirakawa lens that has generated complaints about bokeh, nor is it the only Hirakawa lens that does well on tests (at least on resolution tests). The FA* 85, the FA 77, the DA 40 and especially the FA 43 all have reputations for being super sharp. And keep in mind as well: the DA* 55 was designed before Hoya took over. Nor would I judge the philosophy that went into a lens on the bokeh alone.
I would be interested to know: complaints by whom?

What people expect from a $700 lens — a bokeh at the level of a $5000 lens? Or that a 55mm lens has the bokeh of the 105mm or 135mm lens? I'd really love to see all those who complained about it big time, to ascertain is their opinion worth listening at all.

It seems people stubbornly forget these days that lens design is increasingly a matter of rude compromises and a result of severe cost reduction, much more so than 30 years ago. And that it is a darn good luck that at least Pentax is willing to do something else considering enormous constraints on the budget in view of economic times. At least to me it seems that they would rather economise production of cameras, but still retain the flexibility to give users better and more unique lenses.

After reading many complaints on the net, to me it seems everyone would love to have a Pentax lens that behaves like a 50mm Summicron, or like that new uber-xpensive Zeiss 55mm, but that is costs 1/10 of their price. Right?

Well, there is nothing wrong shooting with a plastic Holga. By the way things are moving, in a decade or two it is perhaps all we'd get from any camera manufacturer.

Last edited by Uluru; 12-16-2013 at 01:55 PM.
12-16-2013, 02:13 PM   #401
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We must all remember the changes to glass formulae rendered necessary by European squishes who think children will eat the trace lead particles in the glass (or who hope to "protect" the poor Japanese glass factory workers from their evil corporate overlords). We must also remember that eventually a glass foundry simply wears out and must be replaced, but capital is allocated differently today than it was years ago. In both cases properties of the glass blanks Pentax engineers designed for may no longer even exist, and more likely cannot be replicated at a price the market will accept today (at least from Pentax).

Further, we must accept that small lenses must have small AF motors (at least affordable small AF motors), which must turn smaller amounts of glass, or screwdrive which is thought a noisy, antiquated technology. The design ethic changes with the technology.

Ricoh is beavering away installing modern machines in Pentax plants to bring Pentax manufacturing methods into the late 20th C. (I meant that) - perhaps machines simply cannot do what Pentax formerly could do using its old design-for-assembly-reality methods.

There could be numerous reasons beyond merely the dismissal of lens engineers that Pentax does not design lenses to the old standard today - or that Hoya wanted them not to. There could be numerous reasons engineers were dismissed beyond mere salary economics. perhaps Hoya figured out that to bring precision manufacturing processes to lensmaking so that Pentax could win DXOMark tests would require gobs of capital - so they sold the entire company.

I don't know - do ya think?

Last edited by monochrome; 12-16-2013 at 06:07 PM.
12-16-2013, 02:24 PM   #402
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QuoteOriginally posted by Uluru Quote
I would be interested to know: complaints by whom?

What people expect from a $700 lens — a bokeh at the level of a $5000 lens? Or that a 55mm lens has the bokeh of the 105mm or 135mm lens? I'd really love to see all those who complained about it big time, to ascertain is their opinion worth listening at all.

It seems people stubbornly forget these days that lens design is increasingly a matter of rude compromises and a result of severe cost reduction, much more so than 30 years ago. And that it is a darn good luck that at least Pentax is willing to do something else considering enormous constraints on the budget in view of economic times. At least to me it seems that they would rather economise production of cameras, but still retain the flexibility to give users better and more unique lenses.

After reading many complaints on the net, to me it seems everyone would love to have a Pentax lens that behaves like a 50mm Summicron, or like that new uber-xpensive Zeiss 55mm, but that is costs 1/10 of their price. Right?

Well, there is nothing wrong shooting with a plastic Holga. By the way things are moving, in a decade or two it is perhaps all we'd get from any camera manufacturer.
Class A really doesn't like the DA *55. Not the rendering, not the bokeh, not the sharpness. I personally like it and in the focal length, the only options that are better are the Voigtlander 50mm f1.4 (manual focus, not available new in k mount) and Pentax A 50mm f1.2 (same as the Voigtlander). The 55 does have fairly busy bokeh wide open, but it isn't bad stopped down to f1.8 and it is the sharpest Pentax lens I have used -- sharper than my FA 77.

As you say, life is about compromises. If you want an auto focus lens in this focal length, it is a really nice option.
12-16-2013, 03:20 PM   #403
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It could be any of those things….. the technical end of lens production has apparently advanced so much, that things are possible now that weren't even possible in the past…. and quite possibly there should be a pie chart with all those things and a few we don't know about dividing up the pie with all the factors affecting modern design. It would be so cool to have someone who works in design at Ricoh/Pentax do one. Inquiring minds want to know.
12-16-2013, 03:59 PM   #404
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QuoteOriginally posted by Rondec Quote
Class A really doesn't like the DA *55. Not the rendering, not the bokeh, not the sharpness. I personally like it and in the focal length, the only options that are better are the Voigtlander 50mm f1.4 (manual focus, not available new in k mount) and Pentax A 50mm f1.2 (same as the Voigtlander). The 55 does have fairly busy bokeh wide open, but it isn't bad stopped down to f1.8 and it is the sharpest Pentax lens I have used -- sharper than my FA 77.

As you say, life is about compromises. If you want an auto focus lens in this focal length, it is a really nice option.
I don't have a 55.

The bokeh looks fine to me (but not superb), the rendering looks fine to me. The test results show poor sharpness below F/4.

It's also not... heavy, but certainly not light, either.

To me it was a non-starter because of the SDM issues. The SDM issues seem to have sorted themselves out, though, so if Pentax makes a FF I might consider it.

Last edited by ElJamoquio; 12-16-2013 at 05:05 PM.
12-16-2013, 04:23 PM   #405
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QuoteOriginally posted by monochrome Quote

There could be numerous reasons beyond merely the dismissal of lens engineers that Pentax does not design lenses to the old standard today - or that Hoya wanted them not to. There could be numerous reasons engineers were dismissed beyond mere salary economics. perhaps Hoya fuigured out that to bring precision manufacturing processes to lensmaking so that Pentax could win DXOMark tests would require gobs of capital - so they sold the entire company.

I don't know - do ya think?
Asahi Optical which became Pentax was — as it name suggests — an optics company. Despite designing cameras, we may assume majority of their workforce were optics engineers. If they needed to cut the jobs for mere salary economics, they'd economise within the largest group of employees, I'd suspect, no?
Besides, we indeed don't know details, and it's worthless presuming anything sinister or vile. Last information I've heard is that they are hiring again; but not advertising so loudly that an average idle grandma hanging around PF would be fully briefed about it.
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