RiceHigh's Pentax Blog: K-5II/IIs: Central Cross AF Sensor Will be Disabled with Most DA Zoom Lenses, and even Some DA Limited Primes!

Monday, October 22, 2012

K-5II/IIs: Central Cross AF Sensor Will be Disabled with Most DA Zoom Lenses, and even Some DA Limited Primes!

(Source: Pentax Japan K-5II/s page, Credit: Blog reader "jaad75".)

Look at the above official diagram and illustration. For the "new" K-5II and K-5IIs, the first thing is that only the central AF point is equipped with the f/2.8 sensor, for the horizontal one. That f/2.8 sensor is unique for being the one and only one f/2.8 AF sensor that the camera has. However, this sensor will NOT work with any lens that is slower than f/2.8! Under such case, the horizontal AF sensor will have no function! That means that the central cross sensor will simply become only a vertical linear sensor with most zoom lenses, except for those very few f/2.8 ones. Moreover, even those slower primes are affected, e.g., the DA21 F3.2 Limited and the DA15 F4 Limited!

At the end of the day, I would rather keep my K-5 and do the AF fine adjustment in a precise way instead if I have to sacrifice like that, which is even more problematic IMHO! :-o

After all, my last prediction is correct! Pentax is yet to do thing in the easiest but cheapest way, without taking the real drawback caused as a result into account! >:-|

Related:-

K-5II User Manual is Put Online

What is the Exact Layout of the f/2.8 AF Sensor(s) in the K-5II/s?

Focus Adjust the K-5 and Pentax AF Lenses with Live View

Again, Why a "f/2.8" AF Sensor is Crucial for Higher AF Accuracy!

Comments (25)

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+8 Vote up Vote down

Djay · 647 weeks ago

"After all, my last prediction is correct!".
Seeing the past wrongly correct prediction you made lately, I'd wait to have a camera in hand to verify this hunch on a badly drawn schematic.

+2 Vote up Vote down

Wider · 647 weeks ago

Nonsense. 2.8 AF sensor works with any lens.

14 replies · active 646 weeks ago

-5 Vote up Vote down

RiceHigh 110p · 647 weeks ago

You are really funny! A f/2.8 AF sensor that doesn't need a f/2.8 or faster lens? Thats the biggest joke that I've heard this year! Pardon?

+3 Vote up Vote down

Wider · 647 weeks ago

double cross 2.8 sensor in ANY camera of ANY brand works with any lens even slower f2.8. your antiscientific conclusions are funny.

-4 Vote up Vote down

RiceHigh 110p · 647 weeks ago

The *official* diagram by Pentax above does NOT show anything that you *imagined*!

+2 Vote up Vote down

Alex · 646 weeks ago

There is nothing in the *official* diagram (which is of course simplified, excluding pretty much every technical detail except for the AF points position and sensitivity to horizontal/vertical details) which would indicate that the horizontal component of the central AF point can't work with slower than f/2.8 lenses. Nothing at all.
As usual, you've made up the most unfavourable - and extremely unlikely - scenario.

By the way, it appears Pentax has a different opinion than yours: http://cocolo-no-paradise.cocolog-nifty.com/parad... http://cocolo-no-paradise.cocolog-nifty.com/parad...

+1 Vote up Vote down

Leon · 646 weeks ago

the horizontal sensor is actualy a doble sensetive it is a F5.6 and F2.8. SO all GOOD :-)Leon

-2 Vote up Vote down

RiceHigh 110p · 646 weeks ago

That diagram was imagined by the poster, there is no official information of such a design.

+2 Vote up Vote down

Alex · 646 weeks ago

No, *you* were imagining things.
That diagram was made after an official Pentax presentation.

-1 Vote up Vote down

RiceHigh 110p · 646 weeks ago

Oh, "was made"? "After"? What do you want to tell actually?

+2 Vote up Vote down

Alex · 646 weeks ago

Exactly what I wrote.
But maybe you believe making up things out of thin air is more reliable than using a technical presentation? I wouldn't be surprised.

0 Vote up Vote down

RiceHigh 110p · 646 weeks ago

How "reliable" is a diagram drawn by someone who is actually unknown but just attended a marketing briefing? On the same basis, I am sure that YOU can write even "better" things, as *imagined*!

+1 Vote up Vote down

Alex · 646 weeks ago

Oh, so it's better to make things up, ignoring an official presentation full of technical details? Like you made up the "lack" of an IR-cut filter, on the K-5 IIs?

Don't try to make me a supporter of your BS - unlike you, I'd rather act and think according and not in spite of available information.

-1 Vote up Vote down

RiceHigh 110p · 646 weeks ago

The "official presentation" contains no more "technical details" than the above official AF layout diagram that the *same* Pentax Ricoh posts at their website. After all, you still do not admit that the diagram you have been referring to is nothing official.

And, if you want to "discuss" on the filter archectiture of the K-5 and K-5IIs, please go back to the relevant post and try not to distract from this topic when you've already found no more valid "point" to argue and then "try to make things up" after that.

+3 Vote up Vote down

Alex · 646 weeks ago

Well, Ricey, I never expected you would actually read those pages. You know, this one: http://cocolo-no-paradise.cocolog-nifty.com/parad...
And the next one: http://cocolo-no-paradise.cocolog-nifty.com/parad...
And the next one: http://cocolo-no-paradise.cocolog-nifty.com/parad...
And the next one: http://cocolo-no-paradise.cocolog-nifty.com/parad...
Or at least the first page, which is talking about the AF (not only diagrams, but text also).
By the way, if you have doubts about how the diagram was made why won't you ask the author? Afraid of the answer?

And you being wrong, i.e. contradicting publicly available information from Pentax themselves is a reality, not something I'm making up. You also have a habit of not correcting your mistakes, even if evidence is provided.

+3 Vote up Vote down

Wider · 647 weeks ago

Go to Canon or Nikon forums and declare your silly conclusion - it will be funny too

+5 Vote up Vote down

jaad75 · 647 weeks ago

As I told you before - Your "prediction" is not necessarily correct and there is a scheme that makes more sense: http://www.pentaxforums.com/forums/members/28598-...
BTW, f/2.8 sensors are not immediately "blind" just above f/2.8...

2 replies · active 647 weeks ago

-5 Vote up Vote down

RiceHigh 110p · 647 weeks ago

The official diagram is clear and exact.

+5 Vote up Vote down

jaad75 · 647 weeks ago

No, it's just a marketing picture that says about f/2.8 sensitive point in the center which might be just a horizontal sensor (if it's not too many conclusions drawn from a simple picture), but doesn't say much about how the actual array looks like. There is still a couple of options and you might be right as well as you might be not...

0 Vote up Vote down

Arn · 647 weeks ago

It should be easy to check with someone who owns a K5II or IIs and a few lenses.
A focus test on a horizontal & vertical motif should do the trick easily.

1 reply · active 647 weeks ago

-1 Vote up Vote down

RiceHigh 110p · 647 weeks ago

I think Pentax needed not to advertise fewer if they had more! Also, the above is actually so specific!

+3 Vote up Vote down

Trolle Yeager · 647 weeks ago

This entire site is one big vanity troll blog. Every "update" is some trolling commentary designed to needle and invoke a response from Pentax users. RiceHigh ... go outside more. Everyone else, ignore this self-important troll.

3 replies · active 646 weeks ago

-3 Vote up Vote down

Geo · 646 weeks ago

What is your problem?? If you don't like what he writes--don't visit his site. You do realize that by visiting his blogsite you add to his visitor count,right?
It's his site- so he can basically write what he wants. I don't always agree with him but it's better than all the apologists and fanboys for Pentax.
I like to find out the problems and foibles of the equipment so I can make an informed decision on what to buy and what to skip.

+2 Vote up Vote down

Trolle Yeager · 646 weeks ago

I think I may have fewer problems than you Geo. Got a little hot tempered there did we ? Relax. You'll live longer, and be better company. Good for you for stepping up to defend a simple troll site. I'm sure you enjoy endlessly looking for validation of your next purchase. Bit insecure are we ? Prefer internet browsing for "problems and foibles" to going out and taking photos ? Know all the specs of your computer but never used it to create anything ? Well done :-)

-1 Vote up Vote down

Geo · 646 weeks ago

Well Trolle- name is fitting I think. It's good to see you back at RH's site, boosting his numbers for visitors.
Don't you think you should "go outside more" and "ignore this self-important troll". It seems you find it hard to follow your own advice..

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Monday, October 22, 2012

K-5II/IIs: Central Cross AF Sensor Will be Disabled with Most DA Zoom Lenses, and even Some DA Limited Primes!

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