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02-16-2011, 07:39 AM   #586
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QuoteOriginally posted by jolepp Quote
Thanks for pointing this out. However the Sigma 1:1.4 is 2 stops faster than 1:2.8 and so EV 2.3 with that would mean an amount of light for the AF sensor to work corresponding to EV 4.3 for a 1:2.8 lens where my K-5 seems to work fine. Trying the Sigma around EV 1 in tungsten light would seem like a way of reproducing the problem - or not .
As you can see in that post I also used the Sigma in single candle's light below EV0. And as I already wrote in this topic, I did the same test with DA* 16-50 and results were the same. There goes your 1.4 - 2.8 theory....

My (second, replacement) cam works fine, took hundreds of real portraits and candids in <4EV and ~2EV conditions with f/1.4 and f/2.8 lenses - that's the only thing that matters to me. To be honest I don't care any more what some random people think or believe on the internet, if they believe all K-5 must be bad then let them do so, fortunately that doesn't affect how my camera works.

02-16-2011, 09:31 AM   #587
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I for one don't know how equivalent tungsten and candle light actually are. At any rate, as I keep saying, it is quite possible that some K-5s work just fine in low tungsten light (without the assist light at, say, EV 3 for a 1:2.8 lens, or EV 2 for a 1:2 lens or EV 1 for 1:1.4 one).

However, as it is, it seems I cannot refer to a posted test that would demonstrate this beyond reasonable doubt either because they don't exist, I have missed them or there is wiggle room in the test circumstances (or for some other reason, such as being an unreasonable dimwit myself ). Seeing one would be interesting in general and potentially useful in practice: if other copies work just fine where mine has problems, an exchange would make sense, otoh it would not, if copies that do not have a similar problem are non-existent (or even rare). In the latter case waiting to see if the firmware update makes a difference would seem to make more sense.

Don't take me wrong: I appreciate anyone taking the trouble to do tests and post the results (and being exposed to the naysayers ). I'm not sure the problematic circumstances have been narrowed down as much as possible; tungsten light is the primary suspect, which is unfortunate as it remains pretty common in circumstances where the K-5 high ISO would really shine without this. Whether there are accomplices yet to be caught (such as spefic copies of a lens and or K-5s) is still unclear IMO .
02-16-2011, 10:06 AM   #588
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QuoteOriginally posted by simico Quote
Como se puede ver en este post que también se utiliza el Sigma en la luz de la vela solo por debajo de EV0. Y como ya escribí en este tema, hice la misma prueba con DA * 16 a 50 y los resultados fueron los mismos. Ahí va el 1,4 a 2,8 teoría ....
El Pentax 16-50, y otras lentes SDM y HSM, no tienen este problema de FF.

El problema de FF es sobretodo con lentes de enfoque por tornillo.

Aunque tambien hay algunas SDM que si les afecta, como el 50-135 o el 60-250.

En mi tienda, he probado mas de 150 cámaras Pentax K-5 bajo las mismas circunstancias controladas y entre 2EV y 4EV bajo cierto tipo de luz, especialmente de tungsteno, todas presentaron el mismo FF.

La ultima información que dispongo es que Pentax trabaja en ello.

Saludos...
02-16-2011, 10:53 AM   #589
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QuoteOriginally posted by jolepp Quote
I for one don't know how equivalent tungsten and candle light actually are. At any rate, as I keep saying, it is quite possible that some K-5s work just fine in low tungsten light (without the assist light at, say, EV 3 for a 1:2.8 lens, or EV 2 for a 1:2 lens or EV 1 for 1:1.4 one).

However, as it is, it seems I cannot refer to a posted test that would demonstrate this beyond reasonable doubt either because they don't exist, I have missed them or there is wiggle room in the test circumstances (or for some other reason, such as being an unreasonable dimwit myself ). Seeing one would be interesting in general and potentially useful in practice: if other copies work just fine where mine has problems, an exchange would make sense, otoh it would not, if copies that do not have a similar problem are non-existent (or even rare). In the latter case waiting to see if the firmware update makes a difference would seem to make more sense.

Don't take me wrong: I appreciate anyone taking the trouble to do tests and post the results (and being exposed to the naysayers ). I'm not sure the problematic circumstances have been narrowed down as much as possible; tungsten light is the primary suspect, which is unfortunate as it remains pretty common in circumstances where the K-5 high ISO would really shine without this. Whether there are accomplices yet to be caught (such as spefic copies of a lens and or K-5s) is still unclear IMO .

The confusion is stalling a lot of us that had plans to already have a K5 by now. Nothing seems crystal clear about any of this, the number of affected cameras, the severity, the circumstances....nothing really is clear as daylight.....except that these problems exist in the K5 and we never heard it on the K7? What everyone wants is some solid information, some glimmer of hope, some reality we can all trust. When and if that will come is as much a mystery as the issue itself. We all have questions...we all want answers.
Regards

02-16-2011, 11:02 AM   #590
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my head is spinning..... i've got a simple question regarding the k-5, the issue being bandied about is front focus issues/problems under tungsten lighting....
i get that.. however,
does this beauty of a new body have any focus issues in daylight, low light (natural, i.e. dusk +dawn), or anything other than tungsten situations ????
why i ask is that i MUST have the k-5, and if i avoid the tungsten lighting scenario, i should hopefully be okay with all other lighting environments, hence, no big deal for my shooting needs..am i on target??????
i have no limited lenses, , but use a variety of other nice lenses, kiron 105mm 'a', sigma 70-200mm f2.8 non macro, sigma 24-70mm f2.8 non macro, sigma 105mm f2.8 macro...
and also don't want to have to go through circus gyrations to have them work properly with a new k-5...... also a non problem???
thanks for the response(s).... much appreciated... dave m
02-16-2011, 11:54 AM   #591
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QuoteOriginally posted by dcmsox2004 Quote
my head is spinning..... i've got a simple question regarding the k-5, the issue being bandied about is front focus issues/problems under tungsten lighting....
i get that.. however,
does this beauty of a new body have any focus issues in daylight, low light (natural, i.e. dusk +dawn), or anything other than tungsten situations ????
why i ask is that i MUST have the k-5, and if i avoid the tungsten lighting scenario, i should hopefully be okay with all other lighting environments, hence, no big deal for my shooting needs..am i on target??????
i have no limited lenses, , but use a variety of other nice lenses, kiron 105mm 'a', sigma 70-200mm f2.8 non macro, sigma 24-70mm f2.8 non macro, sigma 105mm f2.8 macro...
and also don't want to have to go through circus gyrations to have them work properly with a new k-5...... also a non problem???
thanks for the response(s).... much appreciated... dave m
Cannot speak for anyone else, but I tried 3 K5 bodies and all had significant FF in LOW light regardless of the color temp of the light source. I tested extensively and the effect was clear.

I also have to agree with jolepp that I have not yet seen any convincing proof that any K5will focus correctly in low light. In fact, I have seen many such images where the claim was that the K5 F worked well when the image was clearly FF or not focused at all, or the image was taken at higfher light levels or at apertures where the problem would not show up.

This is simple to test even without any fancy light sources or targets; simply AF on something in dim light with the PDAF system and then do so again with LV. The difference is obvious.

For me, the slide to FF was obvious in any light temp as the light was reduced and the cameras all had a significant step to FF below EV4. One was somewhat better than the others, but not anywhere near the specification of AF to EV-1.

I do not recall seeing posts abot the K7 doing this, but at least one poster at the other forums has a K7 acting exactly the same as the K5s I have tested.

This information is all available by searching, BTW...

Ray

Last edited by Ray Pulley; 02-16-2011 at 12:13 PM.
02-16-2011, 12:13 PM   #592
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QuoteOriginally posted by Ray Pulley Quote
Cannot speak for anyone else, but I tried 3 K5 bodies and all had significant FF in LOW light regardless of the color temp of the light source. I tested extensively and the effect was clear.

I also have to agree with jolepp that I have not yet seen any convincing proof that any K5 wil focus correctly in low light. In fact, I have seen many such images where the claim was that the K5 F worked well when the image was clearly FF or not focused at all, or the image was taken at higfher light levels or at apertures where the problem would not show up.

This is simple to test even without any fancy light sources or targets; simply AF on something in dim light with the PDAF system and then do so again with LV. The difference is obvious.

For me, the slide to FF was obvious in any light temp as the light was reduced and the cameras all had a significant step to FF below EV4. One was somewhat better than the others, but not anywhere near the specification of AF to EV-1.

I do not recall seeing posts abot the K7 doing this, but at least one poster at the other forums has a K7 acting exactly the same as the K5s I have tested.

This information is all available by searching, BTW...

Ray

thanks ray..... appreciate your concise response .... just what i wanted to know... did hear from a fellow forum member who has no ff issues whatsover.... go figure... tis a puzzlement.... wonder if newer production bodies will have new (and silent) firmware updates installed before pentax releases the firmware to others... it'd be a gray day if the new and stunning silver k5 coming out the door soon has ff issues as well..... i'd spend the xtra $$ for it.... just don't want the myriad of focus issues so many have to deal with... regards, dave m
02-16-2011, 12:13 PM   #593
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Low Light

I don't know if I understand exactly what everyone one means by low light but I can tell you (a. I have taken a lot of pictures in my home in all sorts of lighting conditions without flash (including lens tests) and I have not experienced FF issues. (b. Pentax is selling an awful lot of K-5's and (c. I have yet to see a professional review comment on the issue and there are quite a few reviews on the street.

02-16-2011, 12:33 PM   #594
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QuoteOriginally posted by mgm2 Quote
I don't know if I understand exactly what everyone one means by low light but I can tell you (a. I have taken a lot of pictures in my home in all sorts of lighting conditions without flash (including lens tests) and I have not experienced FF issues. (b. Pentax is selling an awful lot of K-5's and (c. I have yet to see a professional review comment on the issue and there are quite a few reviews on the street.
AFAIK, reviews are not done at low light levels.

Regardless, do a search and you wil find all sorts of comments about the soft K5 images seen in initial reviews. Some reviews were re-shot and did improve, but this issue goes back well into last year just after the camera came out and has been reported consistently in forums all over the world.

I do keep hearing about K5s that focus perfectly in low light, but my experience with 3 bodies was very consistent and is well documented in these forums.

I would love to see some properly focused images below EV3 where the AF assist did not come on, as that would give some hope that Pentax can address the issue somehow. Otherwise, many will not buy a K5 and some (like me) will have to move on to another brand to get the K5 performance improvements that I do need.

Ray
02-16-2011, 12:54 PM   #595
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QuoteOriginally posted by Ray Pulley Quote
I would love to see some properly focused images below EV3 where the AF assist did not come on, as that would give some hope that Pentax can address the issue somehow. Otherwise, many will not buy a K5 and some (like me) will have to move on to another brand to get the K5 performance improvements that I do need.

Ray
I'm not sure that having some bodies focus correctly would give hope in the way you suggest. It would seem to me that if ALL bodies behaved identically, then possibly a setting could be changed to adjust things. But if it is variable, then do they have to change the setting to something different in each camera? More difficult to achieve via firmware update...
02-16-2011, 01:17 PM   #596
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I don't know if this helps anyone in the decision making about the K5.
I have had mine for about 3 months now and am extremely happy with the camera.
I am not setting out to extend into greatly exaggerated perameters purely find a fault somewhere.
I take the photos I want from macro to tele, in what light is available at any given time, and have had no problems at all.
In fact, I am very, very pleased with low light performance up to this time.

2 shots taken, without use of flash, for sample purposes:

K5/DA35mm :1/45sec/F2.8/iso6400. Extremely poor light. Focus on the word "Inside".



K5/Pentax M 50mm 1.4. : F4/1/20sec/iso3200



This is posted purely for information. I am not out to prove/disprove anybody's point.
A lot has been said for and against this camera for a long time now, and I have got to the point where I don't follow much of it anymore. I just take photos, and if something comes up that shows a problem then I will followup on it.

K5.....for me ..its great
02-16-2011, 01:26 PM   #597
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QuoteOriginally posted by Bramela Quote
Focus on the word "Inside"
i can see obvious front focus on that picture.... even at this size....
02-16-2011, 01:42 PM   #598
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QuoteOriginally posted by filorp Quote
i can see obvious front focus on that picture.... even at this size....
But isn't your subject in focus even if it is front focusing? Now if the "Inside" was out of focus and the front was in focus, that would be a problem in my mind. But if the subject is still inside the focus range, is that an issue?
02-16-2011, 01:44 PM   #599
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QuoteOriginally posted by Bramela Quote
I don't know if this helps anyone in the decision making about the K5.
I have had mine for about 3 months now and am extremely happy with the camera.
I am not setting out to extend into greatly exaggerated perameters purely find a fault somewhere.
I take the photos I want from macro to tele, in what light is available at any given time, and have had no problems at all.
In fact, I am very, very pleased with low light performance up to this time.

2 shots taken, without use of flash, for sample purposes:

K5/DA35mm :1/45sec/F2.8/iso6400. Extremely poor light. Focus on the word "Inside".



K5/Pentax M 50mm 1.4. : F4/1/20sec/iso3200



This is posted purely for information. I am not out to prove/disprove anybody's point.
A lot has been said for and against this camera for a long time now, and I have got to the point where I don't follow much of it anymore. I just take photos, and if something comes up that shows a problem then I will followup on it.

K5.....for me ..its great
Thanks. The first shot is very consistent with the best K5 body I tried. It is approximately EV3 or a bit below and the FF is just about to the limit of the DOF.

More and more evidence keeps piling up that all K5s have this problem and that some are a bit better than others, but still consistent FF on low light.

Maybe that is good news in terms of getting a universal fix should Pentax ever choose to address this issue. The kr seems to have the same problem, which is interesting as the two bodies have somewhat different AF systems.

I just cannot fathom why this has not been addressed yet given all of the noise all over the world about it? This has to be affecting sales and showing up in warranty costs.

Ray
02-16-2011, 01:52 PM   #600
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QuoteOriginally posted by jrforman Quote
But isn't your subject in focus even if it is front focusing? Now if the "Inside" was out of focus and the front was in focus, that would be a problem in my mind. But if the subject is still inside the focus range, is that an issue?
It would be if the aperture was set to 1.4 or 1.2

Anyone can take a pic with a smaller aperture and wider DOF and claim there isn't a problem.

That pic is about EV3 and it's front focussing. lets see the same shot at EV2 or below at f/1.4
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