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12-14-2008, 07:41 PM   #31
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Two Things to Tray

QuoteOriginally posted by phler2 Quote
Hi everyone

i am glad to see people are concerned here and are trying to sort things out.

i have been looking at technical aspects of pictures generated by the k20, as you might have seen on my post on dpreview (see link a few post higher in this thread)

i continued exploring. and there is bad news here : yes some images are very badly affected by the problem of this noise banding. but in fact pretty much all images are. let me explain here. it is not a noise problem :
it is a parasitic signal, or a signal interfering, not a noise : it is an horizontal high frequency (yielding vertical bands) and it is present even when your eyes don't see it on most pictures.

given the systematic (all the surface of the image is affected) vertical aspect and i suspect it could have to do with the electronics in the reading of the sensor. that said i don't know how the sensors is read put probably by scanning it horizontally.

a very simple fft reveals high power level at 1/2 the maximum Nyquist frequency which is definitely not noise. i can clearly observe it at different iso settings at and it is not only on the first shots of a series of shots that is affected (even thought it is the case for images that are heavily affected )

i would like your help here, if you have a k20d that has not shown to be problematic, can you send me some shots raw+jpegs
take shots of walls with plain colors or something like that, at different iso/exposure time.
please sent the data to l e r o u x 0 0 - a t - y a h o o - d o t - fr
i'll give you some feedback.

thanks

P
Are you using the battery grip? It has been known to induce some banding, which was first seen on some K10D cameras.

Try a different SD card. As as improbable as it may seem (to me as well) I have seen more than one instance of various banding issues resolved by using a different card.

I have seen some images with banding induced by nearby electrical sources as has been discussed recently at the "other" forum. These cases seem to involve very strong nearby signals such as might come from microwave towers and other strong sources.

BTW, I have not experienced any banding on either of my K10d cameras, or my K20D other than the dreaded VPN wnhich can be induced on any K10D I believe (not really banding, per se).

It would be helpful to post some samples so we could see what it is you are talking about.

Ray

12-14-2008, 07:53 PM   #32
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QuoteOriginally posted by Ray Pulley Quote
You missed the point:
Of course, since this is the internet, you two electronic experts clearly know better than the design engineers at Hoya/Pentax......
Ray

dude, i understand what you mean, in that yes pentax is probably going to be reluctant recognizing there is a problem that could be bad design/ production defect, if it happens outside the range of operating conditions.

that said, the specific problem we have here, and i am repeating myself, is not *due* to cold. it is merely (and not necessarily systematically) exaggerated by cold. and again, as i said, the problem often happens with temp higher than 0.

on an other point, your posts are not being any helpful at understanding the problem so to eventually debug it sort it out and give some important information to pentax engineer so they get a fix.

and sure you know why intel says their mobos may not work below 0?
no, it's not battery (except for portable devices)
perhaps its is problems related to condensations that could, be bad on the mobo. (but did you ever tried intel mobos cooled with liquid nitrogen, works great and far below 0 )
that said again : the k20d is definitely advertised to be weather proof and water resistant, and if condensation forms inside its electronics, then pentax would have to work on it given its on guaranty..
12-14-2008, 08:02 PM   #33
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Ray, please se the post on dpreview i gave link for
please see the first thread i refered to at the begining of this trhead

no it's not related to batery grip
it's clearly not related to RF (some shots are far far away form any rf in the montains)

it's not the SD either, i tried differetn, others have too

as far as i know, it is not vpn form the k10d.

the problem is very specific in its nature (the precise 1/2nyquist horizontal frequency)
go see this post
Re: K20D, don't like cold temperatures?: Pentax SLR Talk Forum: Digital Photography Review

thanks
12-14-2008, 11:04 PM   #34
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QuoteOriginally posted by phler2 Quote
dude, i understand what you mean, in that yes pentax is probably going to be reluctant recognizing there is a problem that could be bad design/ production defect, if it happens outside the range of operating conditions.

that said, the specific problem we have here, and i am repeating myself, is not *due* to cold. it is merely (and not necessarily systematically) exaggerated by cold. and again, as i said, the problem often happens with temp higher than 0.

on an other point, your posts are not being any helpful at understanding the problem so to eventually debug it sort it out and give some important information to pentax engineer so they get a fix.

and sure you know why intel says their mobos may not work below 0?
no, it's not battery (except for portable devices)
perhaps its is problems related to condensations that could, be bad on the mobo. (but did you ever tried intel mobos cooled with liquid nitrogen, works great and far below 0 )
that said again : the k20d is definitely advertised to be weather proof and water resistant, and if condensation forms inside its electronics, then pentax would have to work on it given its on guaranty..

Dude? How '80s

We have been over this sort of thing ad nausem with various camera problems over the years. Someone has a problem, or a few people have a problem, and suddenly everyone has design "advice" for the manufacturers. Maybe you guys should all get together and design your own cameras.

Regardless, in a few cases, the cameras have had systematic faults that were indeed found by the users and widespread or even in all cameras of that type. In a few cases, those faults were fixed. In many other cases (maybe even most), they were not (like the dreaded K10D VPN and alleged K10D focusing issues).

I have been shooting Pentax since 1978, and have owned all but the IstD of the digital series from Pentax, so I have seen it all. If you think that these posts, or even emails to Pentax with images will make any difference, I am sad to say that you will be disappointed.

Time after time people have been advised to simply send the camera back for repair. If it has a fault that can be reproduced, and the fault happens while being used within the specifications and operating range of the camera (and it is still under warranty) then Pentax has an obligation to fix it.

If the fault is widespread or inherent in the design, the only real way to get the attention of Pentax is for lots of cameras to be returned to fix the problem under warranty.

To paraphrase a famous rock legend, "you will get no satisfaction" from Pentax for a camera problem here on an internet forum. This is especially true if you have not even bothered to let them try and reproduce your problem and repair the camera.

To get back to the problem at hand, I have given you the only situations I am aware of with similar banding in Pentax cameras, and after 15,000 + istds images, 10,000 or so K100D images, 20,000 + K10D images, and over 5,000 on the K20D so far, I am happy to say that I have never seen such a pattern, not even a single time.

Perhaps the issue is related to certain modes or shooting conditions, or attached lenses, or more likely, just a faulty camera that needs repair....

I guess at the end of the day, my "helpful" advice is for you to send it back for repair with sample images that have the EXIF intact and see what Hoya/Pentax has to say. I have had really good service from Pentax the few times I have had to use the repair service.

Ray

12-15-2008, 12:01 AM   #35
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QuoteOriginally posted by Ray Pulley Quote
You missed the point:

Everything has a set of operating conditions and specifications, your car and your camera. Use them outside of these parametrs at your own risk, and there are no promises that anything will work correctly, and in almost all cases you would void your warranty by doing so. BTW, that includes Canon gear. Go ahead and try to get Canon to fix your camera under warranty if it behaves incorrectly when used outside of the specifications.

Electronics defiintely behave differently above and below the specified operating ranges and all electronics have such specs. Of course folks like Intel must also be less smart than you are because they specify 0 - 55C operating range on the Motherboards they make. Maybe that is also just about battery life, eh?

Cameras have shutters, aperture mechanisms, plastic parts, shake reduction assemblies, gears and other mechanical assemblies that all have specified operating ranges. Dimensions and sizes of various precision parts change with temperature, as do the various physical properties of the materials used in the product. The design has to take all of this into account and set limits upon the operating range inside of which the cameras is designed to work.

As for Engineers, well let's just say that I have been manufacturing electronic assemblies designed by EE's for more than 30 years (which currently includes specialized digital cameras) and what I have learned about engineers is that there are some good ones, and many bad ones, but I have yet to meet one that would say that the specified operating conditions of the equipment they designed is meaningless. Most are also clueless about most things mechanical, just as you two appear to be.

Of course, since this is the internet, you two electronic experts clearly know better than the design engineers at Hoya/Pentax......

Ray
A little bit condescending with your closing sarcasm.

I did not miss your point.

Manufacturers always place conservative recommended operating temperatures on their electronics. I will admit that I omitted I glossed over some other reasons for the 0 degrees limit, such as mechanical components (but mechanics is old hat, I never encountered a properly maintained mechanical camera that could not handle -30 c). Also, the LCD should never be exposed to extreme temperature for risk of catastrophic damage. The other issue with temperature extremes is expansion/contraction of the circuits. But this is more a problem with larger circuits, such as what one will find in an Intel motherboard. And, as previously stated, the other big problem is condensation.

Unless I missed a caveat, I will reiterate that overall, electronics actually work more efficiently at colder temperatures.

Getting back to the REAL ISSUE, it is reasonable to assume that the K20D should function perfectly at all the temperatures this would normally encounter in the real world. It's NOT an Intel motherboard that is normally expected to operate at room temperature. Rather it is a portable device that should be designed to operate in a much wider range of temperatures. If Canon and Nikon can build their cameras this way, I expect Pentax to do the same.
12-15-2008, 12:12 AM   #36
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QuoteOriginally posted by ManuH Quote
Here is one clear example:

That's interesting but could you please provide more information such as the EXIF data.

The banding is definitely to the other independent examples I have also seen.

Something else that might be revealing to know is your camera's serial number. Perhaps this problem only affects a series of cameras (part number versions could have changed at some point in manufacturing?). Also, what firmware version are you using?
12-15-2008, 05:28 AM   #37
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Believe it or not, I've seen that happen once w/ the K10D. I wish I kept the picture... :-P
12-15-2008, 07:46 AM   #38
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QuoteOriginally posted by Ray Pulley Quote
Dude? How '80s

I guess at the end of the day, my "helpful" advice is for you to send it back for repair with sample images that have the EXIF intact and see what Hoya/Pentax has to say. I have had really good service from Pentax the few times I have had to use the repair service.

Ray
Ray, i have send it back, it took 5 weeks to get it resent to me with with a simple notice "the camera is working"
took it out on weekend, and had the problem immediately

i got my seller to call pentax, she talked to a stupid idiot, maybe it was his bad day, sure. i will be sending it back again.

if you have no problem with your k20 please send me pictures of it as i asked (shots of plain color at different iso), so that i can analyze them and see if there is really no problem (the problem is present but not always visible as can attest my fft test in matlab)

no the problem is not related to specific conditions/lenses/...
i've had it last friday at a party when shooting portrait, with al kind of lenses.

12-15-2008, 07:48 AM   #39
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QuoteOriginally posted by pentaxmz Quote
Something else that might be revealing to know is your camera's serial number. Perhaps this problem only affects a series of cameras (part number versions could have changed at some point in manufacturing?). Also, what firmware version are you using?
my camera:

Manufacture Date : 2007:12:22
Production Code : 2.1
Internal Serial Number : 14901
12-15-2008, 07:56 AM   #40
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QuoteOriginally posted by Ray Pulley Quote
Dude? How '80s

We have been over this sort of thing ad nausem with various camera problems over the years. Someone has a problem, or a few people have a problem, and suddenly everyone has design "advice" for the manufacturers. Maybe you guys should all get together and design your own cameras.

Ray

i don't know what your referring to about the 80's, is it the expression "dude" i used or something else. english is not my first language.

i repeat myself though, your posts are not very interesting, if you don't want to help in there, go have some fun elsewhere.

fyi, this problem here is very particular (see the fft i posted). enough that pentax engineers definitely need to pay attention. and they're probably actually doing so for some time, but not talking about it, because they haven't sorted it out and don't want to do bad advertisement.
12-15-2008, 09:35 AM   #41
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QuoteOriginally posted by phler2 Quote
my camera:

Manufacture Date : 2007:12:22
Production Code : 2.1
Internal Serial Number : 14901
Hello Philippe,

Where did you obtain the above information. All I see is the s/n on the bottom of the camera.
12-15-2008, 09:38 AM   #42
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I think you can use this tool

PhotoME - Exif, IPTC & ICC Metadata Editor

i use exiftool in command line under linux

on any images the data is in the exif information
12-15-2008, 10:04 AM   #43
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From your other thread

Apparently it occurres in the Nikon d200 as well.......
Maybe searching the Nikon sites will reveal the cause.
guess I'm a bit surprised in the fact it's in a 20d w/ a CMOS sensor. Leads me to believe it's a problem not related to the sensor but more to do w/ a bad board/ ADC/ power supply....whatever

Nikon D200 Reviewed. Noise Performance
Discussion Forums @ Nikonians - D200 and banding
CCD Noise Sources
Looks like silkypics can remove it..
http://www.isl.co.jp/SILKYPIX/englis...letter/051222/



https://www.pentaxforums.com/forums/pentax-dslr-discussion/24253-k20d-dithering-problem.html
12-15-2008, 10:05 AM   #44
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QuoteOriginally posted by pentaxmz Quote
A little bit condescending with your closing sarcasm.

I did not miss your point.

Manufacturers always place conservative recommended operating temperatures on their electronics. I will admit that I omitted I glossed over some other reasons for the 0 degrees limit, such as mechanical components (but mechanics is old hat, I never encountered a properly maintained mechanical camera that could not handle -30 c). Also, the LCD should never be exposed to extreme temperature for risk of catastrophic damage. The other issue with temperature extremes is expansion/contraction of the circuits. But this is more a problem with larger circuits, such as what one will find in an Intel motherboard. And, as previously stated, the other big problem is condensation.

Unless I missed a caveat, I will reiterate that overall, electronics actually work more efficiently at colder temperatures.

Getting back to the REAL ISSUE, it is reasonable to assume that the K20D should function perfectly at all the temperatures this would normally encounter in the real world. It's NOT an Intel motherboard that is normally expected to operate at room temperature. Rather it is a portable device that should be designed to operate in a much wider range of temperatures. If Canon and Nikon can build their cameras this way, I expect Pentax to do the same.
It's NOT just a Pentax problem. See my post above. BUT it is a faulty camera and should be repaired/replaced. Bottom line.
12-15-2008, 12:50 PM   #45
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yup, thought i wish pentax wouldnt take another 5 weeks to tell me they couldnt reproduce the problem.

interesting info you got there on nikon. i'll go tho the store tomorrow and probably buy a Km so i dont miss a camera for the holidays.

thanks
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