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Forum: Pentax News and Rumors 6 Hours Ago  
HD Pentax-D FA★ 85mm f/1.4 SDM AW
Posted By Kunzite
Replies: 201
Views: 13,423
That's a new low - that "Peter" guy cut the source text specifically to alter its meaning to the exact opposite of what was claimed.
This is lying. There's no excuse that it's "only" in the title, since the title sticks.
Forum: Pentax SLR Lens Discussion 1 Day Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
Using JPEG would be a serious mistake. But I'll give them the benefit of the doubt, as their wording is vague.

"RAW image" is used a lot.

Hmm... I wanted to say Optical Limits, but the results (with lenses tested on the corresponding 16MP Nikon) are close, and the excellent D FA 50mm macro is doing well.
Klaus even warns against comparing the numbers for different systems.
Forum: Pentax SLR Lens Discussion 1 Day Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
I always forget people aren't as literal in their reading as me in my writing :o
Pentax lenses measured worse, that's strictly about numerical results in various tests.
I'm not saying, "Pentax lenses are worse", or even "less sharp". I know that isn't true. So how come even the best Pentax lenses - IMHO as good as everything else - don't measure as they should? Even against themselves?
Forum: Pentax SLR Lens Discussion 1 Day Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
Well put.
And yes, this is partly the result of much criticism at various Pentax lenses, and partly toward my own professional quirks that makes me want an explanation when a test doesn't seems to match reality.
It has little to do with enjoying seeing the images; we're not only allowed to discuss about the most important things, right? :)
Forum: Pentax SLR Lens Discussion 1 Day Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
Norm, I paid for the upgrade after pixel peeping until my eyes bled (and deciding there's no detail loss to talk about). I totally get it. I'm also a happy owner of the D FA 28-105, and on APS-C I used the DA Limiteds.

But this is about charts... not photography, but this thread and my question.
Forum: Pentax SLR Lens Discussion 1 Day Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
I know you folks are trying to be helpful and I truly appreciate it... but please, pay attention to the question when answering.
"Same" lens (under Pentax and some other brand), different test results on Pentax vs. e.g. Nikon. This cannot be about lens design philosophies.

And you won't see me claiming this is important. OK, it is somewhat important for brand perception but that's it.
Forum: Pentax SLR Lens Discussion 1 Day Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
And in the real life.
Forum: Pentax SLR Lens Discussion 2 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
See ephotozine's latest Pentax reviews, those for which they're giving numbers rather than "excellent/good/etc" - no lens will get close to 3500lw/ph.
Yet Nikon's best lenses can approach 4000lw/ph, on a D810. Even a zoom like the 70-300 will reach 3500 (@f11)...
Forum: Pentax SLR Lens Discussion 2 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
Of course it can. But every single time?
Forum: Pentax SLR Lens Discussion 2 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
Except for the glass stack thickness in front of the sensor, which isn't correct for all lenses:
Lens Rentals | Blog
Forum: Pentax SLR Lens Discussion 2 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
There's also a discrepancy between numerical tests results and real life results and yes, I merely want to know why.
Or, it's just me pretending my D FA* 50mm f/1.4 doesn't lose in terms of resolution to some Canikony kit lens ;)
Forum: Pentax SLR Lens Discussion 2 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
MTF50 and no, Pentax doesn't reach the same numbers (I won't say performance) as the competition - at least not according to ephotozine and OpticalLimits (the latter admits to using different sharpening, but also warns against directly comparing systems).
IMO this isn't something we can attribute to sample variation; it's too uniform. Although in case of the 70-210, the resolution drop at the longer end could be sample variation, or a slight misfocus.

About CA (lateral CA) we're talking about a measured difference from under a quarter of a pixel to almost a pixel (for the Pentax, respectively Tokina 50mm).
Forum: Pentax SLR Lens Discussion 2 Days Ago  
Pentax 70 - 210 vs Tamron 70 - 210 | Lens Review
Posted By Kunzite
Replies: 108
Views: 3,348
Ridiculous.
Forum: Pentax SLR Lens Discussion 2 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
Of course; and I already mentioned it as testing "better" in terms of CA and maximum resolution.
Forum: Pentax SLR Lens Discussion 3 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
But this can't be the design philosophy if the "same" lens gets different results.
Forum: Pentax SLR Lens Discussion 3 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
Just to be clear, I'm not obsessing either about CA nor the lower resolution numbers. If I did, I'd have jumped ship long ago, to a brand measurably "better" (but which I'd like less to use). On the contrary, I'm happy with all my D FA lenses.
I'm only curious about the discrepancy... "same" lens, different results.


Right. Do we have one here? :)
Forum: Pentax SLR Lens Discussion 3 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
Are you saying Pentax' image processor is adding CA? :rolleyes:
Forum: Pentax SLR Lens Discussion 3 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
Imatest doesn't even recommend using MTF50 for testing.

A good thread, thanks, but it doesn't explain why e.g. the Pentax D FA* 50mm has higher CA than the Tokina Opera. And I'm 100% sure the Image Accelerator doesn't add CA... :rolleyes:

Of course, I knew about Pentax pursuing actual image quality rather than test results. But now I wonder, what if Pentax wasn't uniformly slightly "worse" than the competition, if there are other factors why the numbers weren't as high (or low)?
Forum: Pentax SLR Lens Discussion 3 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
My claim is that they're measuring worse, and I'd like to find out why.
Being measured wrong is just one possible cause; and it could be as simple as using a slightly different processing (which Photozone/Optical Limits actually does).
Forum: Pentax SLR Lens Discussion 3 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
There is no NR "baked in" at base ISO in the K-1 II, and I sure hope reviewers aren't incompetent enough to test at high ISO... and there's no accelerator unit on the K-1, so find the cause elsewhere if you can.
Anti-Pentax rants aren't helpful. Just sayin'.
Forum: Pentax SLR Lens Discussion 3 Days Ago  
Pentax 70 - 210 vs Tamron 70 - 210 | Lens Review
Posted By Kunzite
Replies: 108
Views: 3,348
Autofocus in live view.
For Pentax, they might use outoffocus in live view.
Forum: Pentax SLR Lens Discussion 3 Days Ago  
Pentax lenses measured worse?
Posted By Kunzite
Replies: 79
Views: 2,620
I hope you're all well and COV-19 free.

Reading various Pentax lens reviews, and particularly those where there is an other brand version - be it Tamron or Tokina - I've noticed how Pentax lenses tend to measure worse.
For example, the recent Pentax D FA 70-210's resolution falls quite badly at the longer end, and the CA is significantly worse than the Tamron tested on the D810. Or the Tokina Opera, having much less CA than the original Pentax. (That's according to ephotozine, one of the few remaining sites performing in-depth Pentax lens reviews)

The maximum resolution difference could be explained by MTF50 being very dependent on sharpening, although no sharpening should be applied. I cannot accept that basically the same 36MP sensor with no AA filter is somehow less sharp on a Pentax camera; it doesn't make sense.
And what about the CA?

Is it something reviewers consistently are getting wrong? (how could that be?) Is this Canikonyetc cherry picking the lenses sent for review, and Pentax just sending the same beat up sample they're sending everywhere? Is it Canikon's version of the Accelerator Unit applying sharpening and CA reduction? Is the Pentax badge cursed or something? :confused:

I could speculate and guess possible reasons; but I'd rather like to know - so I hope the knowledgeable (and hopefully bored enough ;) ) people here would chime in.
Thanks!
Forum: Pentax News and Rumors 3 Days Ago  
HD Pentax-D FA★ 85mm f/1.4 SDM AW
Posted By Kunzite
Replies: 201
Views: 13,423
Particularly with quite a few "well meaning" gentlemen pretending otherwise ;)
Forum: Pentax News and Rumors 5 Days Ago  
HD Pentax-D FA★ 85mm f/1.4 SDM AW
Posted By Kunzite
Replies: 201
Views: 13,423
Yes, that's precisely the point I was making.
Forum: Pentax News and Rumors 5 Days Ago  
HD Pentax-D FA★ 85mm f/1.4 SDM AW
Posted By Kunzite
Replies: 201
Views: 13,423
I already knew what KAF2 means, and it's quite evident from my post; I also know what I wrote, and properly read what you wrote. The point you are ignoring is that the same KAF2 had different "minor versions".
Adding a pin would not definitely give us KAF5. It might, but then Ricoh Imaging would unnecessarily have to explain compatibility.
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