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01-05-2011, 08:54 AM   #361
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There are times when this particular failure may well be epic, but for many of those times, manual focus is a better option anyway.
Anyway, I believe a couple of posters have indicated that Pentax is working on some sort of fix, and as always, if there are problems, it's the early adapters who will suffer with them.
I do find it odd that this problem took a couple of months to find and now it will cause the end of civilization as we know it.
People expect that according to the specs, the AF should work perfectly to EV-1, with a sharp drop off the pavement below that. I expect that whatever fix we get, there will be a gradual drop off accuracy or efficiency the closer the AF gets to it's limit.
Or, Pentax may have to put a double check system in which kicks in around EV 4, which will slow the AF down to pre K10 levels at lower light levels.

Nothing much has changed. If one truly needs world class AF, there are much better brands out there.
The metric for measurement has modified with the K5, but the reality has not, apparently.

01-05-2011, 09:28 AM   #362
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Hate to say this but this is nonsense...

QuoteOriginally posted by Wheatfield Quote
There are times when this particular failure may well be epic, but for many of those times, manual focus is a better option anyway.
Anyway, I believe a couple of posters have indicated that Pentax is working on some sort of fix, and as always, if there are problems, it's the early adapters who will suffer with them.
I do find it odd that this problem took a couple of months to find and now it will cause the end of civilization as we know it.
People expect that according to the specs, the AF should work perfectly to EV-1, with a sharp drop off the pavement below that. I expect that whatever fix we get, there will be a gradual drop off accuracy or efficiency the closer the AF gets to it's limit.
Or, Pentax may have to put a double check system in which kicks in around EV 4, which will slow the AF down to pre K10 levels at lower light levels.

Nothing much has changed. If one truly needs world class AF, there are much better brands out there.
The metric for measurement has modified with the K5, but the reality has not, apparently.
There isn't "months ago and civilization" - at least for some of us. I got the camera recently. The autofocus fail is in some situations where it has failed in an obvious way where it really should not. And certainly not for a USD $1500 MSRP camera. More so when the camera was billed as having the new autofocus engine it has capable of detecting light wavelength.

It's fine if you are doing daylight shots and this doesn't affect you but I find some of the stuff you write as if everyone is really exaggerating this or making it up which is complete utter nonsense. And for many of those situations, no, manual focusing is not "best", like a wedding or wedding reception in lower light.

What's the point of a camera with a high ISO performance if it's going to not perform well under those conditions? I really think Pentax is working on a fix. When they do, please don't update since apparently you don't need this and it's a total exaggeration by some of us.

Now that doesn't make sense either, does it?

- Raist
01-05-2011, 09:31 AM   #363
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QuoteQuote:
Frankly, I've never had any success with Pentax AF. When the chips are down, Pentax AF has always failed me, irregardless of camera. The best AF I've gotten was using LiveView AF with the K5 in the studio.
It was pretty fast and deadly accurate.
At weddings, I've had AF fail enough times that I just don't use it. K10, K20, K7 have all had one problem or another that for me renders the AF to be useless due to lack of trustworthiness to get a picture at the right time.

My question is, do you think that if they get the AF sufficiently accurate down to EV 0 or so that people will stop complaining, or will they still complain because they can take good pictures at EV -3 or -4 and the AF isn't working?
I think many would. The problem is that obvious. When cameras much cheaper than this one can nail focus what does that tell you? And looking from what you wrote you just don't care much for this. Fine and cool, that's you. Don't then go ahead and put your lack of care/standards on this issue to the rest of us.

If in the end Pentax came out and said "hey, he's right. You will never have success with Pentax AF" I can tell you I wouldn't have touched the K-5 with a ten foot pole.

- Raist
01-05-2011, 10:05 AM   #364
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A lot of frustrations....no doubt about it. Just some words of assurance would be very welcome about now. No use in tempers flaring, or word slinging, it is not what we need. We need something to lift our confidence....at least I do. I know, in the scope of things, what is one shooter? But there are many of us riding in the same boat, and we all share the same or similar concerns. Hoping for the best....fearing the worst.....that is what "in the dark" is all about.
Best Regards

01-05-2011, 10:17 AM   #365
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QuoteOriginally posted by Tommot1965 Quote
1 meter a 50mm F2.8 lens will only have 40mm DOF..at 2 meters that goes up to 180mm..perhaps enough for the increase in DOF
and what if the camera pretty often locks on thin air in front, the whole 3ft in front of a target which is 8ft away? That's what my copy of K-5 tends to do with sigma 30 f1.4 (yes, let's blame the reverse engineering) and, wait for it.... the kit 18-55mm as well! Let's compensate by shooting with massive flashgun at f45. No, wait. can't do that as the sensor stains are far too apparent at any f number over 11. Pay 1000 quid for the privilege of testing and documenting and 100 times over describing to different dimwits in service centres the faults of the product these guys have the audacity to call a FLAGSHIP model. Or was I too lucky with the Kx? Out of 10 (!!!) K-r cameras - some red and some black I tried in the shop - there was NONE that was not severely frontfocusing. I thought Kx I have was dodgy. Now I see that my Kx is a gem, considering the rest of my experiences in Pentax world so far.

Last edited by Mikhail_Kriviniouk; 01-05-2011 at 03:48 PM.
01-05-2011, 10:21 AM   #366
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QuoteOriginally posted by Rupert Quote
A lot of frustrations....no doubt about it. Just some words of assurance would be very welcome about now. No use in tempers flaring, or word slinging, it is not what we need. We need something to lift our confidence....at least I do. I know, in the scope of things, what is one shooter? But there are many of us riding in the same boat, and we all share the same or similar concerns. Hoping for the best....fearing the worst.....that is what "in the dark" is all about.
Best Regards
Well, SRS Microsystems are very nice as a dealer in the UK. You can count on them. And they have no plans of ditching the brand despite the endless obvious QA and QC production deficiencies in the Philippines and total sh*theadedness of Pentax staff... So, deal with your dealer, do not count on Pentax/Hoya
01-05-2011, 10:50 AM   #367
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QuoteOriginally posted by Wheatfield Quote
People expect that according to the specs, the AF should work perfectly to EV-1, with a sharp drop off the pavement below that. I expect that whatever fix we get, there will be a gradual drop off accuracy or efficiency the closer the AF gets to it's limit.
When previous cameras got the focus it was good, or they just couldn't lock. My K-5 locks fast, I have the green light in the viewfinder, but it's totally off in low light. That's where it's deceiving.

Last edited by PhilippeG; 01-05-2011 at 11:06 AM.
01-05-2011, 11:34 AM   #368
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Original Poster
QuoteOriginally posted by Wheatfield Quote

People expect that according to the specs, the AF should work perfectly to EV-1, with a sharp drop off the pavement below that. I expect that whatever fix we get, there will be a gradual drop off accuracy or efficiency the closer the AF gets to it's limit.
Or, Pentax may have to put a double check system in which kicks in around EV 4, which will slow the AF down to pre K10 levels at lower light levels.

Nothing much has changed. If one truly needs world class AF, there are much better brands out there.
The metric for measurement has modified with the K5, but the reality has not, apparently.
WHEATFIELD could you please stop writing down what "PEOPLE EXPECT" !
All forum members are well capable of expressing what they expect from a camera and in most cases that differs from what YOU expect !
If you want to write about what people expect it would be wiser to state that "PEOPLE expect a 1000 Euro plus camera to have proper working AF system. "
But even that is not true as some people are fully happy with the K5 as it is.

01-05-2011, 12:50 PM   #369
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I did a quick test, focused at a painting hanging on the wall. K-5 with old kit lens from the k10d. 18mm focal length, f3,5 iso 3200, range to wall about 2m.

Light from five tungsten bulbs in the cealing, controlled with a dimmer.

At shutter speed 1/50s the focus where ok.

I turn the light down slightly and

at shutter speed 1/40s I get severe ff

So focus ok at LV about 4,2 and severe FF at LV about 3,9

Seems to be in line with others result.


Same test with k10 (except iso1600)

focus ok at LV 3,5
focus starting to FF (not as bad as k-5 though ) at 2,9

So it's nothing new, it has just turned worse. More front focus in brighter light combined with a sensor encouraging low light photography.
01-05-2011, 01:02 PM   #370
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Gimbal - Following up on other suggestions here, if you did the test with AWB, could you please repeat it using Tungsten WB? A focussing software bias could be applied with the various WB settings.
01-05-2011, 01:11 PM   #371
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The test was with tungsten set, I tried it again with AWB and the result was the same. (only tested with k-5)
01-05-2011, 01:29 PM   #372
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Another weird thing is if I zoom in to 55mm I didn't get any FF at all, even if I turned down the light until the camera started to flash with the numbers (indicating it can't take a proper reading).

I continue to turn down the light, focus is spot on, it's getting really dark, and the painting is dark as well. Still the focus assist light hasn't turned on yet.

Shut off the lights completely (a little stray light from nearby room is all that is left) and finally the assist light turns on. At 55mm it never failed down to complete darkness where assist light finally turned on. Hm....weird.
01-05-2011, 01:59 PM   #373
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QuoteOriginally posted by jbinpg Quote
Gimbal - Following up on other suggestions here, if you did the test with AWB, could you please repeat it using Tungsten WB? A focussing software bias could be applied with the various WB settings.
I ran a similar test as Gimbal with a dimmer last night and got nearly identical results. I also saw no difference using AWB and the Tungsten preset.
01-05-2011, 03:40 PM   #374
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QuoteOriginally posted by raist3d Quote
There isn't "months ago and civilization" - at least for some of us. I got the camera recently. The autofocus fail is in some situations where it has failed in an obvious way where it really should not. And certainly not for a USD $1500 MSRP camera. More so when the camera was billed as having the new autofocus engine it has capable of detecting light wavelength.
There appears to be some confusion. Some people report (and have done some fairly convincing tests) that this is not a "light wavelength" (I would call it colour temperature) problem, since it doesn't seem to matter if the lightsource is daylight or tungsten light.
QuoteQuote:

It's fine if you are doing daylight shots and this doesn't affect you but I find some of the stuff you write as if everyone is really exaggerating this or making it up which is complete utter nonsense. And for many of those situations, no, manual focusing is not "best", like a wedding or wedding reception in lower light.
Are you a professional wedding photographer with 4 decades of experience?
I am. and I hate to say it, but what you just posted is nonsense.

QuoteQuote:

What's the point of a camera with a high ISO performance if it's going to not perform well under those conditions? I really think Pentax is working on a fix. When they do, please don't update since apparently you don't need this and it's a total exaggeration by some of us.
And when they fix it and people discover that they can still take decent pictures after the autofocus fails because the imaging sensor is definitely capable of outperforming the AF sensor, people will still whine about it.
QuoteQuote:
Now that doesn't make sense either, does it?

- Raist
Most of what I read here doesn't. Rupert seems to be the most lucid right now.

QuoteOriginally posted by raist3d Quote
I think many would. The problem is that obvious. When cameras much cheaper than this one can nail focus what does that tell you? And looking from what you wrote you just don't care much for this. Fine and cool, that's you. Don't then go ahead and put your lack of care/standards on this issue to the rest of us.

If in the end Pentax came out and said "hey, he's right. You will never have success with Pentax AF" I can tell you I wouldn't have touched the K-5 with a ten foot pole.

- Raist
It tells me that Pentax didn't quite get their camera right this time, and that those of us who are serious about photography need to make sure that we know the strengths and weaknesses of our equipment.


QuoteOriginally posted by Mikhail_Kriviniouk Quote
and what if the camera pretty often locks on thin air in front, the whole 3ft in front of a target which is 8ft away?
......
Then you send your camera back for repair or replacement since it is obviously defective, and for good measure, write a bunch of posts on the internet demanding that everyone at Hoya/Pentax commit Hari Kari.
It's the way things are done nowadays, it seems.


QuoteOriginally posted by bjan Quote
WHEATFIELD could you please stop writing down what "PEOPLE EXPECT" !
All forum members are well capable of expressing what they expect from a camera and in most cases that differs from what YOU expect !
If you want to write about what people expect it would be wiser to state that "PEOPLE expect a 1000 Euro plus camera to have proper working AF system. "
But even that is not true as some people are fully happy with the K5 as it is.
It's painfully obvious what people expect, or at least it is to someone who can read.
As an aside, that 1000 Euro plus camera will never have an AF system that works well enough to please PEOPLE. Even if it was 100% functional down to it's specified EV value, people would still be complaining because it isn't able to AF down to EV-5 or -6, which is the functional limit of the sensor in handheld operation with a fast lens and SR turned on.

I point this out to you as a public service, no need to thank me for it.
01-05-2011, 03:57 PM   #375
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Don't know what to tell you...

QuoteQuote:
"Are you a professional wedding photographer with 4 decades of experience?
I am. and I hate to say it, but what you just posted is nonsense.
It's not showing then. If you are going to act as if you are the only one that knows what he's talking about I reserve the same right then. This is pretty simple- it's not a user error or the like nor is it abnormal to expect a 1,000 quid ($1,500 USD) camera to act like this, particularly a DSLR. There is something clearly off here.

If you think this is acceptable well then that's you. Sounds like you don't user other brands or something (and if you say you do then you clearly have *very low standards*).

So, if you are willing to think this acceptable, I respect your right to espouse that opinion for yourself, but please don't throw around as if "we are so in error" or such stupidity.

Sure, there will be people that close enough is never enough. But that's not what we are talking about here. The error in FF I am seeing is quite obvious, quite off.

Thanks.

- Raist
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