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02-18-2011, 08:25 PM   #676
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QuoteOriginally posted by PixleFish Quote
So what are the chances of pentax fixing the FF on this model...?
At the very least, they need to add a second user bias on the AF to allow users to dial in the AF below an EV cutoff point.

02-18-2011, 08:27 PM   #677
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QuoteOriginally posted by Ray Pulley Quote
CA in the PDAF optics would be consistent, however, and there is one very persistent advocate of this cause over at the other forums.
Actually, this has been my favourite explanation, and I posted it a number of times in the past...

I'm heavily overtired to the extend that I while I thought to myself that normal camera lens characteristics shouldn't be high enough to explain substantial FF, I simply forgot about the AF module being subject to dispersion effects as well.
Time to get some rest...

QuoteOriginally posted by Ray Pulley Quote
In my case, I tested many lenses in different light, reduced both daylight and tungsten light with ND filters on the lenses, used 3 different color filters over the lenses, used a LED light where I reduced the output of the light with the same lens using ND filters, and the only consistent result was a shift to FF at EV 3-4 with any color light.
Was that with the K-5? There should definitely be a difference between the K20D and the K-5. The extra colour sensor in the K-7/K-5's AF modules definitely is meant to compensate AF drift. To the best of my knowledge, it is not used for the camera's WB.
02-18-2011, 08:31 PM   #678
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QuoteOriginally posted by PixleFish Quote
So what are the chances of pentax fixing the FF on this model...?
Good, I think.
There haven't been any reports about the K-7 regarding this issue.

While trying to improve things in one area can always mean that other areas suffer a bit (and this could have happened with the new AF module of the K-5), I'm pretty sure that the Pentax engineers will be able to improve the situation.

It all depends on how straightforward the deviations are, in the sense of how reliably one can detect in which direction to compensate. Falk already indicated that the dependencies are not a 100% straightforward and this might be why we haven't seen a fix yet. I'm sure they want to release their very best fix, not some intermediate incremental improvement.

I think we'll know more when Falk has finished his report. I think it will give us a clue as to which degree the problem might be addressed.

Last edited by Class A; 02-18-2011 at 08:53 PM.
02-19-2011, 02:00 AM   #679
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Age Old Theory

QuoteOriginally posted by Class A Quote
Actually, this has been my favourite explanation, and I posted it a number of times in the past...

I'm heavily overtired to the extend that I while I thought to myself that normal camera lens characteristics shouldn't be high enough to explain substantial FF, I simply forgot about the AF module being subject to dispersion effects as well.
Time to get some rest...


Was that with the K-5? There should definitely be a difference between the K20D and the K-5. The extra colour sensor in the K-7/K-5's AF modules definitely is meant to compensate AF drift. To the best of my knowledge, it is not used for the camera's WB.
The CA theory pre-dates this forum's existence, IIRC. You would have to search the other forum which shall not be named for references there. It is not something anyone can easily prove or test for, however.

I had 3 K5 bodies and all had the same FF issue in low light regardless of color. I have owned 2 K20 bodies and still have one and the K5s I tried were all significantly worse at EV 3-4 and below in any sort of light. So yes the K5 is different than the K20, it is worse.

None of us (that I am aware of) have access to stabilzed and calibrated light sources that allow for precise color and light output changes, nor do we have proper test targets and optical test benches where we can make sure we have perfect alignment of cameras and targets, so anyone can argue with any test that anyone performs.

However, we should not need any such devices to simply walk into a normally lit indoor environment, tungsten or any color temp, and get properly focused images at f5.6 with bounce flash from the $1600 flagship Pentax camera. The issue is very clear in many images posted in forums all over the world. Regardless of the cause, more tests by Falk or anyone else are not going to make all of the users getting results like this suddenly get well focused images, nor is any testing going to show how all of the users like the one below are all doing something wrong:

https://www.pentaxforums.com/forums/pentax-k-5-forum/133556-what-%25%24-%2A-no-1-a.html

After all, the cheapest point and shoot can get these kinds of direct flash shots right with no problem at all, and most of us managed to get shots like this that had acceptable focus all the time with the earlier Pentax bodies.

The istds, k100, K10 and K20 bodies I own(ed) all moved to FF in reduced light. The K5 is far worse than any of these at EV 3-4.

You can also search the other forums and elsewhere and you will find some K7 reports of the same issue, although not as many. It would be interesting to test a K7 in the same manner as has been done on the K5s I had.

Just to be clear, I first noticed the K5 FF issue in normal indoor shooting in a room where I have been shooting for decades (in-laws house at Christmas). I also shot with the K5 at some indoor company events where I have used the K10 and K20 over the years. Even with full AF adjust and f5.6, I was not always able to get sharp images from the K5, so my conclusions are based upon more than just tests I undertook when I assumed that my lenses just needed adjustment on the new camera.

When 12 lenses (or is it 14? I forget ) all behaved in a simlar and consistent fashion on 3 bodies, I needed no more convincing nor tests. The K5 has a problem and so far there has been not a word from Hoya about it, which is not looking good to me.

Ray

02-19-2011, 03:05 AM   #680
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QuoteOriginally posted by Ray Pulley Quote
You would have to search the other forum which shall not be named for references there.
You can link to dpreview in many ways, e.g., putting a space in the URL, using a short URL (-> tinyurl.com/), etc.

QuoteOriginally posted by Ray Pulley Quote
Regardless of the cause, more tests by Falk or anyone else are not going to make all of the users getting results like this suddenly get well focused images, ...
Of course not, but I have a feeling that Falk's findings will give us an idea of how serious the issue is and whether there is hope for a "perfect" fix.

QuoteOriginally posted by Ray Pulley Quote
After all, the cheapest point and shoot can get these kinds of direct flash shots right with no problem at all, ...
You can replicate the same on the K-5 by using LV focus.

QuoteOriginally posted by Ray Pulley Quote
The K5 has a problem and so far there has been not a word from Hoya about it, which is not looking good to me.
  1. Very few claim that there is no problem (I don't belong to this minority).
  2. We've had several reports that Hoya is working on the issue.
Pentax has never been outspoken about future fixes and/or existing problems (the public apology regarding the "sensor stain" issue was a notable exception). Quietness doesn't mean inactivity.

I trust you just need a bit more patience and, FWIW, I think it will be worth it.
02-19-2011, 08:42 AM   #681
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QuoteOriginally posted by Wheatfield Quote
At the very least, they need to add a second user bias on the AF to allow users to dial in the AF below an EV cutoff point.
Indeed but it would have to have a wider range than +/- 10
02-19-2011, 08:45 AM   #682
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QuoteOriginally posted by Class A Quote
You can link to dpreview in many ways, e.g., putting a space in the URL, using a short URL (-> tinyurl.com/), etc.

Forums: Digital Photography Review


Works fine here.
02-19-2011, 09:04 AM   #683
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QuoteOriginally posted by Ray Pulley Quote

Just to be clear, I first noticed the K5 FF issue in normal indoor shooting in a room where I have been shooting for decades (in-laws house at Christmas). I also shot with the K5 at some indoor company events where I have used the K10 and K20 over the years. Even with full AF adjust and f5.6, I was not always able to get sharp images from the K5, so my conclusions are based upon more than just tests I undertook when I assumed that my lenses just needed adjustment on the new camera.


Ray
Sorry to intervene, but the soft results in artificial light + flash made me ditch Kx/K7 and switch to Nikon. I thought that the new combo Kr/K5 will nail that issue but apparently not. I hope Hoya will somehow find a way for the sake of an otherwise excellent camera.

02-19-2011, 09:30 AM   #684
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I don't mean to complain. I love my K5 but the fact that the long anticipated firmware that is supposed to solve all the FF problems has not been released yet after so long is worrying. Makes me wonder if this FF problem is even fixable.
02-19-2011, 09:48 AM   #685
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Pentax Has Had Plenty of Time

QuoteOriginally posted by Class A Quote
You can link to dpreview in many ways, e.g., putting a space in the URL, using a short URL (-> tinyurl.com/), etc.
Sure, but that way does not make fun of the war between the two sites...


QuoteQuote:
Of course not, but I have a feeling that Falk's findings will give us an idea of how serious the issue is and whether there is hope for a "perfect" fix.
I already know how serious the issue is from shooting with and testing 3 bodies with 12 lenses and also from seeing the problem on forums from Asia to Germany to Spain and other English forums like this one and the unnamed one. I have also seen that the Kr has the same issue.

I'm not sure how Falk's findings will have any bearing on a perfect fix unless he has recently signed on with Pentax Engineering. The results will likely be academically interesting, however.


QuoteQuote:
You can replicate the same on the K-5 by using LV focus.
Yes, I can make the K5 focus clumsily and slowly (but accurately) while trying to hold it out in front of me with a heavy pro f2.8 zoom and flash attached just like a point and shoot camera that costs over $1200 less

Using LV to compare does clearly show the problem, however.


QuoteQuote:
Very few claim that there is no problem (I don't belong to this minority).
I did not mean to imply that you did.

QuoteQuote:
We've had several reports that Hoya is working on the issue.
Yes, several unofficial reports, including some with time frames that have long since lapsed. We also have many quotes from folks who have contacted Pentax about the issue where they claim to have never heard of the issue nor seen a camera behaving this way.

Hard to know which to believe.

QuoteQuote:
Pentax has never been outspoken about future fixes and/or existing problems (the public apology regarding the "sensor stain" issue was a notable exception). Quietness doesn't mean inactivity.
Since I have been shooting Pentax since 1978, I do understand that they are a bit less than good at communication. However, it is closer to the truth that in all but the most extreme cases, the issues have simply not been addressed, so quietness has meant inactivity.

To list just a few:

K10D focus issues - Yes, the K10D had FF in low or "tungsten" lighting.
K10D "VPN" - This one needs a chapter of it's own.
SDM failures - No need to open that can of worms, is there?
Kx shutter blur - More worms
Decentered DA* 16-50 lenses
Unsharp 17-70 lenses

I am probably forgetting a few, and in some cases you could send your defective stuff in and get it fixed, but not because Pentax noted the problem and communicated with the buyers. You either played the exchange roulette game trying to get a good copy, or sent it in and often waited weeks or months while service tried to figure out what was wrong or sent it to Japan (sound familiar?).

For the most part, issues that seemed fairly widespread and could be duplicated by many or all were simply left completely unaddressed, or the burden was placed on the buyer to complain and return the product.

QuoteQuote:
I trust you just need a bit more patience and, FWIW, I think it will be worth it.
The K5 would be just about the perfect camera for me, but try a Google search on the FF issue with either the K5 or the Kr and see how many months it has been since the issue surfaced. You will find that the reports go back to not too long after the cameras got into the hands of the users and today there is still no fix or any official word about any fix.

With so many apparently willing to put up with Krs and K5s that do not work right, this long silence has me just about convinced that the issue is going to be just like the shutter blur issue, or SDM failures, or K10D VPN and it will not be addressed.

Ray
02-19-2011, 09:58 AM   #686
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QuoteOriginally posted by gtl Quote
I don't mean to complain. I love my K5 but the fact that the long anticipated firmware that is supposed to solve all the FF problems has not been released yet after so long is worrying. Makes me wonder if this FF problem is even fixable.

I think you are not alone in your wonderment. It may be that the repair would require a hardware fix and after what must have been a very expensive sensor repair, maybe Hoya will just let this ride out unsolved? Or.....we could see a firmware repair any day? No one knows.
I am thinking of buying the K5, after a little more time passes, just to determine if this would be a big disadvantage to me or just a small inconvenience? There are undoubted great features on the K5 even if the AF is not one of them. I can only decide this if I can test one, and since only a tiny number of retailers in America carry Pentax, I must buy one to make a determination. For some, moving to another brand may be the only option, but for me, that is most difficult to undertake, not just because of my Pentax gear, but because I like the Pentax features better than any other camera I have seen. The shooting modes are perfect, the user control and menus are excellent, and the IQ suits my needs and what I see in an image better than most anything else.

Tough decisions, and everyone is different, but sometimes you just have to live with the facts, even if you don't like them. Like grieving, the final step is acceptance. For some of us that comes very hard.
Best Regards
02-19-2011, 12:29 PM   #687
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QuoteOriginally posted by Rupert Quote
I think you are not alone in your wonderment. It may be that the repair would require a hardware fix and after what must have been a very expensive sensor repair, maybe Hoya will just let this ride out unsolved? Or.....we could see a firmware repair any day? No one knows.
I am thinking of buying the K5, after a little more time passes, just to determine if this would be a big disadvantage to me or just a small inconvenience? There are undoubted great features on the K5 even if the AF is not one of them. I can only decide this if I can test one, and since only a tiny number of retailers in America carry Pentax, I must buy one to make a determination. For some, moving to another brand may be the only option, but for me, that is most difficult to undertake, not just because of my Pentax gear, but because I like the Pentax features better than any other camera I have seen. The shooting modes are perfect, the user control and menus are excellent, and the IQ suits my needs and what I see in an image better than most anything else.

Tough decisions, and everyone is different, but sometimes you just have to live with the facts, even if you don't like them. Like grieving, the final step is acceptance. For some of us that comes very hard.
Best Regards
Pentax has to be working on this, if only to know the answer for the next model. Nikon seems to use the focusing assist light a lot, when i last shot with 2 Nikon friends at indoor theatre, the focus assist lights were on for every shot, (for a D90 and a D7000) If nothing else, they should be able to turn that focus assist light on earlier for the K5 - i'm unclear as to if thats already been done - too many posts. I would bet they would issue a firmware on this, and sooner rather than later. But they have to be careful not to mess up the cameras already reported to be working (investigation takes time i'm afraid)

Like Rupert, i'm probably just going to buy and see how much of an impact, if any, this issue will be. From most reports, i believe i would be much better off with the K5 than without. Heck, i did sort of a self-portrait from a tripod last night and a flashlight was enough to get my K20 focus anchored before I started shooting, so there are usually workarounds.

I'm not sure what the title for the shot should be; perhaps
"Searching for the K5"

[IMG][/IMG]

Last edited by philbaum; 02-19-2011 at 03:36 PM.
02-19-2011, 03:04 PM   #688
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QuoteOriginally posted by philbaum Quote
Nikon seems to use the focusing assist light a lot, when i last shot with 2 Nikon friends at indoor theatre, the focus assist lights were on for every shot, (for a D90 and a D7000)
Funny that you mention this as I was just at a party and someone with a Nikon D5000 (I think) taking pictures. The focus assist light keep coming on, and it's not even that dark ... it's pretty annoying too, but at least it's not red. My other friend has a Canon 5D and focuses without problem.
02-19-2011, 03:31 PM   #689
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QuoteOriginally posted by mrbrightside Quote
Funny that you mention this as I was just at a party and someone with a Nikon D5000 (I think) taking pictures. The focus assist light keep coming on, and it's not even that dark ... it's pretty annoying too, but at least it's not red. My other friend has a Canon 5D and focuses without problem.
We are not supposed to use flashes to avoid disturbing the actors, so i asked these two Nikon owners if they could possibly turn their assist lights off, but neither one knew if or how they could do that. The 4th guy, like myself had a K20 and we had no difficulty focusing without assist lights. As you said, they seem intrusive to me also, i wouldn't want to be using them in a crowded indoor environment. Later i read a post that implied they can be turned off. We in fact did have a complaint from an actress after the play, but i think that may have been a popup flash that was accidentally tripped.
02-19-2011, 07:50 PM   #690
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D7000 l
aF assist light seems intrusive to me as well, but it can be turned off. It seemed to focus well without it (within reason)
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