Pentax Germany statement regarding K-r AF problems

Started Dec 1, 2011 | Discussions
GeneralLee Contributing Member • Posts: 655
Pentax Germany statement regarding K-r AF problems

I know there are a lot of threads about the AF performance of the K-r in low light, especially in tungsten light. But I haven't read anything like this so far and it might be of interest for some, so I thought it deserved another thread.

I contacted Pentax regarding whether a fix for the K-r low-light front-focus issue can be expected. Here is the response of the "Product Manager & Group Leader Marketing D / A / CH, Pentax Ricoh Imaging Company", Wolfgang Baus:

My translation:

Your inquiry is legitimate, and I can confirm your concerns.

Yes, there is a specific spectrum of the light in which autofocus cannot operate precisely.

So far this range was not relevant as one had to use flash anyway. Only new cameras reach this (physical) threshold.

In principle it is relatively easy to solve this problem by measuring the light temperature and correcting the focus for it.

As this is not possible, we probably will not offer a solution to this problem .

Original in German:

Ihre Anfrage ist genauso berechtig wie Ihre Befürchtung.

Und beides kann ich bestätigen.

Ja es gibt ein bestimmtes Spektrum des Lichts in dem der Autofokus nicht exakt arbeiten kann.

Dieser Bereich war bisher nicht relevant, weil man eh blitzen musste. Nur mit neuen Kameras kommt man eben an diese Grenze, die physikalischer Natur ist.

Die Problembeseitigung ist eigentlich auch relativ simpel. Es müsste im Vorwege die Lichttemperatur gemessen werden und mit diesem Wert die Fokusmessung korrigieren.

Da dies nicht geht, wird es von uns sehr wahrscheinlich keine Lösung des Problems geben.

Cheers,
Johann

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jotor
jotor Senior Member • Posts: 1,719
Re: Pentax Germany statement regarding K-r AF problems

GeneralLee wrote:

In principle it is relatively easy to solve this problem by measuring the light temperature and correcting the focus for it.

As this is not possible, we probably will not offer a solution to this problem .

I guess this means that Pentax is unprincipled.

;^)

Joe

Johann

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Gary Martin
Gary Martin Veteran Member • Posts: 4,705
Re: Pentax Germany statement regarding K-r AF problems

Yes, there is a specific spectrum of the light in which autofocus cannot operate precisely.

So far this range was not relevant as one had to use flash anyway. Only new cameras reach this (physical) threshold.

In principle it is relatively easy to solve this problem by measuring the light temperature and correcting the focus for it.

As this is not possible, we probably will not offer a solution to this problem .

I own a K200D which will auto focus accurately in situations (eg. low light in warm tungsten) where my K-r does not. So this explanation doesn't pass the smell test. However, I believe them when they say "we probably will not offer a solution to this problem," unfortunately.

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glanglois Contributing Member • Posts: 987
Re: Pentax Germany statement regarding K-r AF problems

Gary Martin wrote:

I own a K200D which will auto focus accurately in situations (eg. low light in warm tungsten) where my K-r does not. So this explanation doesn't pass the smell test. However, I believe them when they say "we probably will not offer a solution to this problem," unfortunately.

The Pentax reply suggests that the K-r can be used in lower light (without flash) than the K200D. So some users will be trying to get K-rs to focus in light that they would not try to shoot with a K200D. That rather matches my understanding but I own neither bodies. Is that right?

OTOH, are you simply saying that the K-r will not focus accurately at light levels at which the K200D will yield acceptable images re: noise?

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Russell Evans Forum Pro • Posts: 12,617
Re: Pentax Germany statement regarding K-r AF problems

GeneralLee wrote:

In principle it is relatively easy to solve this problem by measuring the light temperature and correcting the focus for it.

As this is not possible, we probably will not offer a solution to this problem .

The question is: Which part is not possible, measuring the light temperature, or correcting the focus?

If the measuring the the light temperature is the issue, then a simple workaround would be to simply attach the control to the manual setting of light temperature in question.

If the correcting of the focus is not possible, then the issue is a little more fuzzy. We know there is a debug menu in the camera whether we have access to it or not, that can adjust the focus to some degree. What we don't know is if that adjustment is large enough to correct for the issue.

It would seem pretty stupid for Pentax not to fix this if all it took was a firmware tweak to tie the AF correction to the manual color temperature control, so the only assumption left is that the AF correction needed is too large for the mechanical adjustment in the camera and they knew this at the design level.

So the question is how much does this mean to you in terms of your use of the camera? Is it so high that you would return the camera under the implied warranty?

Thank you
Russell

Barry Fitzgerald Forum Pro • Posts: 29,888
Re: Pentax Germany statement regarding K-r AF problems

I don't really buy that I've been shooting in pretty low light levels with my older Km5d for years comfortable at ISO 1600 and I'd even stretch to ISO 3200 at times if you get a decent exposure (ie not underexposed) you'd be fine.

That camera whilst fairly hmm for AF speeds today (about average at the time) wasn't actually bad for AF accuracy you got misses but it would hit the spot in low kelvin light no problem most times.

And another point is this the light levels don't have to even be that low it's the light temp and when it's around sub 3000k the K-r runs into serious problems. I've never used a camera prior to this that had a specific AF issue related to light temp even my film bodies nope didn't make any difference if there is adequate contrast they'd AF just fine.

It might be late in the day for a fix but there are alternatives available to Pentax if they have new models coming very soon..they could offer a trade in/exchange scheme. Situation as it stands is very unsatisfactory.

Gary Martin
Gary Martin Veteran Member • Posts: 4,705
Re: Pentax Germany statement regarding K-r AF problems

glanglois wrote:

Gary Martin wrote:

I own a K200D which will auto focus accurately in situations (eg. low light in warm tungsten) where my K-r does not. So this explanation doesn't pass the smell test. However, I believe them when they say "we probably will not offer a solution to this problem," unfortunately.

The Pentax reply suggests that the K-r can be used in lower light (without flash) than the K200D. So some users will be trying to get K-rs to focus in light that they would not try to shoot with a K200D. That rather matches my understanding but I own neither bodies. Is that right?

OTOH, are you simply saying that the K-r will not focus accurately at light levels at which the K200D will yield acceptable images re: noise?

What I'm saying is that the K200D can accurately focus in low levels of tungsten light when the K-r cannot. Noise is a different issue. But good high ISO performance is useless if the subject is not properly focused.

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Brad99 Veteran Member • Posts: 3,145
Re: Pentax Germany statement regarding K-r AF problems

GeneralLee quoted...

So far this range was not relevant as one had to use flash anyway. Only new cameras reach this (physical) threshold.

Flash is irrelevant as the AF is done using ambient lighting in the conditions people are having a problem with, i.e. the AF assist light isn't coming on, and anyway that's only good at short range as is flash.

Barry Fitzgerald Forum Pro • Posts: 29,888
Re: Pentax Germany statement regarding K-r AF problems

Gary Martin wrote:

What I'm saying is that the K200D can accurately focus in low levels of tungsten light when the K-r cannot. Noise is a different issue. But good high ISO performance is useless if the subject is not properly focused.

Pretty much sums up the problem

The chances of getting an AF hit are pretty low on the KR in such situations. It can also miss even if the light levels are not that low.

OP GeneralLee Contributing Member • Posts: 655
New statement

I got a new mail today:

Translation:

Perhaps your idea to activate the AF assist beam earlier is not bad, I will discuss it.

At first there was a similar problem with the K-5, but here it could be fixed because the sensor allows it.
I cannot confirm whether there is a colour temperature sensor in the K-5.

There are a lot of issues that have come up durig the development of digital cameras. A lot of these have been solved succesfully, however sometimes new problems were created by doing so.
So far the successors always have been improved in this regard.
I'm very optimistic for the next generation of cameras.

Not too helpful (and not very well-informed imho).

Original:

Eventuell ist Ihr Ansatz gar nicht so verkehrt einfach das AF Hilfslicht schon früher zu aktivieren. Dies werde ich einmal diskutieren.

Anfangs gab es eine ähnliche Problematik, in der K-5. Hier hat man es unter Kontrolle gebracht weil der Sensor es zulässt.
Ob ein Farbtemperatursensor drin ist vermag ich nicht zu bestätigen.

Es gibt sehr viele Dinge, die im Laufe der Entwicklung von Digitalkameras aufgekommen sind. Herausforderungen wurden wirklich gut gelöst, aber auf der anderen Seite wurde dadurch eine neue Baustelle geschaffen.

Bisher war es aber immer so, dass die Folgemodelle entsprechend verbessert waren.
Ich bin für die neue Modellgeneration auf jeden Fall sehr zuversichtlich.

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Barry Fitzgerald Forum Pro • Posts: 29,888
Re: New statement

GeneralLee wrote:
I got a new mail today:

Translation:

Perhaps your idea to activate the AF assist beam earlier is not bad, I will discuss it.

At first there was a similar problem with the K-5, but here it could be fixed because the sensor allows it.
I cannot confirm whether there is a colour temperature sensor in the K-5.

There are a lot of issues that have come up durig the development of digital cameras. A lot of these have been solved succesfully, however sometimes new problems were created by doing so.
So far the successors always have been improved in this regard.
I'm very optimistic for the next generation of cameras.

Not too helpful (and not very well-informed imho).

Keep pushing obviously the problem is here "right now" and it won't go away either!

I don't know on the K-5 I simply have had just a grab of one and I was not looking at AF in low kelvin lighting so it's impossible for me to know if it has problems or not.

New models that don't have the problem might be some comfort if and when they are released, but it doesn't exactly help K-r users.

My experience of quite a few cameras in the past didn't reveal any "problems" with low kelvin AF in fact it just was not an issue that arose ever, at all.

My guess is that the new Safox unit was not field tested properly and for some reason they tried out some new design which probably introduced the issue.

I'd again ask for K-r users to contact their regional service and raise this issue the most we get the better chance we have of something happening.

Gary Martin
Gary Martin Veteran Member • Posts: 4,705
Re: Pentax Germany statement regarding K-r AF problems

Barry Fitzgerald wrote:

Gary Martin wrote:

What I'm saying is that the K200D can accurately focus in low levels of tungsten light when the K-r cannot. Noise is a different issue. But good high ISO performance is useless if the subject is not properly focused.

Pretty much sums up the problem

The chances of getting an AF hit are pretty low on the KR in such situations. It can also miss even if the light levels are not that low.

Hmmm, that's not my experience, but then my testing has not been exhaustive. I get my worst front-focusing outcomes when using the FA50 and DA35. The DA40 seems to focus fine, and the DA70 does pretty well most of the time. At my office, which uses fluorescent lighting, the K-r focuses pretty accurately even in low light, which reinforces my impression that this is a color temperature issue. The latest firmware also made the problem a lot less severe for me. But I've read posts from other K-r owners who have had auto focusing problems even in other lighting sources, so there may be quality-control factors as well, which complicates this whole issue.

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Pentax_Prime
Pentax_Prime Senior Member • Posts: 2,505
Move On

The K-r is old news; they aren't going to offer you any kind of firmware, nor are they going to update the K20 again. If you have an issue - sell your camera and move on. Continually starting new threads to whine about it make you look like trolls.

GeneralLee wrote:

I know there are a lot of threads about the AF performance of the K-r in low light, especially in tungsten light. But I haven't read anything like this so far and it might be of interest for some, so I thought it deserved another thread.

I contacted Pentax regarding whether a fix for the K-r low-light front-focus issue can be expected. Here is the response of the "Product Manager & Group Leader Marketing D / A / CH, Pentax Ricoh Imaging Company", Wolfgang Baus:

My translation:

Your inquiry is legitimate, and I can confirm your concerns.

Yes, there is a specific spectrum of the light in which autofocus cannot operate precisely.

So far this range was not relevant as one had to use flash anyway. Only new cameras reach this (physical) threshold.

In principle it is relatively easy to solve this problem by measuring the light temperature and correcting the focus for it.

As this is not possible, we probably will not offer a solution to this problem .

Original in German:

Ihre Anfrage ist genauso berechtig wie Ihre Befürchtung.

Und beides kann ich bestätigen.

Ja es gibt ein bestimmtes Spektrum des Lichts in dem der Autofokus nicht exakt arbeiten kann.

Dieser Bereich war bisher nicht relevant, weil man eh blitzen musste. Nur mit neuen Kameras kommt man eben an diese Grenze, die physikalischer Natur ist.

Die Problembeseitigung ist eigentlich auch relativ simpel. Es müsste im Vorwege die Lichttemperatur gemessen werden und mit diesem Wert die Fokusmessung korrigieren.

Da dies nicht geht, wird es von uns sehr wahrscheinlich keine Lösung des Problems geben.

Cheers,
Johann

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Gris Gris Man Junior Member • Posts: 48
Hmmm, aren't you more or less fitting the description of troll?

Maybe you want to give up and "move on" when encountering a problem. Please feel free to do so. Others want to work to resolve issues that affect others. Even if Pentax never fixes the K-r problems the feedback will have the potential to improve future products.

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Barry Fitzgerald Forum Pro • Posts: 29,888
Re: Hmmm, aren't you more or less fitting the description of troll?

Forget Pentax Prime believe me if he had a problem with his camera we'd def hear about it!

There is no trolling going on, but there is a discussion in a number of threads which are for the benefit of K-r users. I would have hoped most would support that. Pentax Prime doesn't give a damn about our K-r problems. Even if I didn't have a K-r I would support users wanting a fix.

I'm not selling my camera as I'll lose money but if all else fails I'll get a full refund for it.

Pentax_Prime
Pentax_Prime Senior Member • Posts: 2,505
Re: Hmmm, aren't you more or less fitting the description of troll?

I don't own a K-r; so, while you may be moving on, I'll stick around and enjoy my K-5s. Sound good? Thx

Gris Gris Man wrote:

Maybe you want to give up and "move on" when encountering a problem. Please feel free to do so. Others want to work to resolve issues that affect others. Even if Pentax never fixes the K-r problems the feedback will have the potential to improve future products.

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Pentax_Prime
Pentax_Prime Senior Member • Posts: 2,505
Re: Hmmm, aren't you more or less fitting the description of troll?

Barry Fitzgerald wrote:

Forget Pentax Prime believe me if he had a problem with his camera we'd def hear about it!

Yeah? Find me a thread I've started complaining about equipment I own. You won't - good try though kid.

Pentax doesn't give a damn about our K-r problems.

I do believe you are correct, for once.

I'm not selling my camera as I'll lose money but if all else fails I'll get a full refund for it.

BTW how is that Sony forum ... from which you are permanently banned for trolling ? Oops!

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Barry Fitzgerald Forum Pro • Posts: 29,888
Re: Hmmm, aren't you more or less fitting the description of troll?

Pentax_Prime wrote:

Yeah? Find me a thread I've started complaining about equipment I own. You won't - good try though kid.

Well I saw a thread where you were moaning about aperture blades oh sorry all those got deleted by the admin obviously they didn't think it added to the discussion.

Just like your post in this thread it adds nothing and is designed to dismiss a perfectly valid point.

Kid? Well nice try but it's not going to work pal

BTW how is that Sony forum ... from which you are permanently banned for trolling ? Oops!

Maybe it's time to get a ban on this forum. You have some very serious issues my friend, I'd take them somewhere where they get the attention they deserve

Gris Gris Man Junior Member • Posts: 48
Not sure what this "moving on" gibberish is.

I guess for you tossing out non sequitur barbs is viewed as constructive. Seems quite the opposite to others. No need to thank me, it was my pleasure to point out your faulty logic.

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Terry k Regular Member • Posts: 102
please keep this thread on track

This thread and many others like it were started to discuss a problem with a current Pentax dSLR model, the K-r. I think that this topic and its resolution (or lack thereof) is indeed a suitable topic for forums such as this one. Personal attacks and off subject personal suggestions are not needed, and do not contribute to this thread or its purpose. We all have our pet peeves and foibles. Live and let live.....

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